Pharmacology Flashcards

Question

What is the role of angiotensin-converting enzyme?

Answer 1

It converts Angiotensin I to angiotensin II.

Answer 2

decrease proteinuria promote vasodilation and ventilation reduce plasma volume All of the above sums to decrease systolic blood pressure ACEi can also decrease the metabolism of vasodilatory agent bradykinin resulting in decrease in vascular tone.

Answer 3

ACE inhibitors

Answer 4

Enalapril and Benazepril

Answer 5

ACEi is not a recommended fist line treatment for cats as it does not sufficiently nor consistently lower blood pressure. Benazepril may be beneficial in conjunction with calcium channel blocker.

Answer 6

There is potential to worsen glomerular filtration rate and renal function through preferential dilation of the efferent arteriole that would thereby decrease glomerular filtration pressure. Overall risk is low unless the patient also being treated with diuretic therapy or the patient has severe azotemia.

Answer 7

hyperkalemia secondary to inhibition of aldosterone. However, this is unlikely to be clinically relevant event when given in conjunction with aldosterone antagonist such as spironolactone.

Answer 8

Blocks the ability of angiotensin II to activate its receptors. It does not affect the metabolism of bradykinin.

Answer 9

Do not use in severely dehydrated or azotemic patients

Answer 10

aldosterone antagonist

Answer 11

Block the effects of aldosterone on the distal convoluted tubule and collecting duct.

Answer 12

It is a steroid hormone produced by the adrenal cortex when stimulated by Angiotensin II. It helps control the balance of water and salts in the kidney by keeping sodium and releasing potassium from the body.

Answer 13

Induces vascular remodeling in the glomerulus to retain sodium and water resulting in systemic hypertension. Aldosterone also exerts proinflammatory effects promoting fibrosis.

Answer 14

Hyperaldosteronism

Answer 15

hypertension hypernatremia hypokalemia mostly in chronic kidney disease

Answer 16

development of hyperkalemia. However, this is unlikely unless used with ACEi, ARBs or Beta blocker

Answer 17

Dihydropyridines are a type of calcium channel blocker (CCB) that block calcium channels located in the muscle cells of the heart and arterial blood vessels, thereby reducing the entry of calcium ions into the cells. By blocking these channels, CCBs promote: vasodilation increase strength in contractility minimal effect on cardiac conduction though the decrease in blood pressure may trigger a reflex tachycardia. E.g. Amlodipine and Nicardipine

Answer 18

Amlodipine because it has shown to be more effective than ACEi. If the cat is refractory to amlodipine, then it may require an addition of ACEi or ARB

Answer 19

Reflex tachycardia weakness, lethargy and decrease in appetite intrarenal hemodynamics --> CCB promotes preferential afferent arteriolar dilation over the efferent arteriole, which may result in increased intraglomerular pressure, resulting in damage to the glomerulus and worsening proteinuria.

Answer 20

It can help manage SHT, especially if the underlying mechanism is sympathetically driven.

Answer 21

Selective alpha 1 antagonist to promote smooth muscle vascular relaxation.

Answer 22

Dopamine antagonist with the potential to cause hypotension and GI upset

Answer 23

Beta 1 selective antagonist Decreases heart rate and contractility Reduces renin release and peripheral vascular resistance Used more in cats with SHT and hypethyroidism Used in dogs as adjunct for refractory SHT with reflex tachycardia

Answer 24

Non-selective beta antagonist Decreases heart rate and contractility Reduces renin release and peripheral vascular resistance

Answer 25

Excessive bradycardia

Answer 26

Injectable mix of alpha and beta antagonists. Used to manage severe acute hypertension promotes vasodilation and prevents associated tachycardia The use has been explored in dogs undergoing craniotomy or adrenalectomy

Answer 27

Promotes vasodilation by altering smooth muscle intracellular metabolism. works primarily on arteries Causes vasodilation, afterload reduction and lowering of blood pressure The mechanism is not entirely understood but the end result is smooth muscle relaxation and decrease in peripheral vascular resistance. It is not used as a first-line drug but used as an adjunct in chronic management. Injectable form used in urgent/emergent treatment due to its potent vasodilatory effects, and rapid onset.

Answer 28

Arteriolar vasodilator excessive or irreversible hypotension reflex tachycardia sodium and water retention GI upset

Answer 29

Arteriolar vasodilator promotes potent vasodilation through release of nitric oxide. Nitric oxide diffuses to vascular smooth muscle decrease influx of calcium, activation of actin/myosin chains and overall contractile forces Effects: smooth muscle relaxation and decreased vascular tone and peripheral vascular resistance The injectable form has a short half-life and is easy to titrate, so it is ideally used for hypertensive crises. Administer as CRI. Used to treat acute hypertensive crises or fulminant CHF Contraindicated in hypotensive patients

Answer 30

promotes potent vasodilation through release of nitric oxide. Nitric oxide diffuses to vascular smooth muscle decrease influx of calcium, activation of actin/myosin chains and overall contractile forces Effects: smooth muscle relaxation and decreased vascular tone and peripheral vascular resistance The injectable form has a short half-life and is easy to titrate, so it is ideally used for hypertensive crises. No risk of cyanide poisoning

Answer 31

generation of cyanide and thiocyanate at high doses and prolonged use. Patients with kidney and liver disease have decreased metabolism, therefore greater risk of cyanide toxicity. Clinical signs of toxicosis: metabolic acidosis, depression, stupor, seizures

Answer 32

Selective agonist of dopamine 1 receptor. Promotes peripheral and renal vasodilation and natriuresis Increases glomerular filtration rate Injectable has a short half life. Good potential for application in hypertensive crisis, but needs further investigation in vet med.

Answer 33

Sodium channel blockers Interferes intracellularly with sodium conduction through sodium channels Subclassification determined by potency of effects on sodium channel, activated/inactivated blockade and effects on other channel receptors.

Answer 34

Quinidine and procainamide Effective against ventricular and supraventricular arrhythmias. fast sodium channel blocking effects and moderate blockade of rapid component of the delayed rectifier potassium current resulting in action potential elongation.

Answer 35

Class 1 A antiarrhythmic Sodium channel blocker Depresses conduction velocity and prolongs refractory period in a variety of tissues, including atrial and ventricular myocardium Administer slowly IV over 5-10 minutes to prevent hypotension Adverse effects more commonly associated with cats and humans; include anorexia, nausea, and vomiting

Answer 36

Inhibits fast sodium channels, primarily in the open and inactivated state, with rapid onset. Sodium current is also inhibited, resulting in the shortening of action potential in normal myocardial tissue Lidocaine and mexiletine

Answer 37

Class IB antiarrhythmic Sodium channel blocker. The ability of lidocaine to block sodium currents is better during acidosis. Benefit: minimal hemodynamic, SA, AVN affect at standard doses Hepatic clearance determines serum concentration Heart failure, hypotension, and severe hepatic disease can decrease lidocaine metabolism and predispose patients to lidocaine toxicity. Adverse effects: higher incidence in cats Nausea, vomiting, lethargy, tremors, seizure activity (usually symptoms stop when lidocaine is discontinued) Dosing: Bolus 2mg/kg over 20-30 seconds; bolus can be repeated up to 8mg/kg within 10 minute period barring adverse effects CRI: 25-75mcg/kg/min

Answer 38

Class 1B antiarrhythmic most common oral class in dogs Highly protein-bound and excreted by the kidneys Use and adverse effects similar to Lidocaine (rarely used in cats because of adverse effects)

Answer 39

Class 1B antiarrhythmic Similar to lidocaine, rarely used in small animals because of high incidence of serious adverse effects including renal failure and corneal dystrophy

Answer 40

Potent blockade of the open state fast sodium channel with greater effects as the depolarization rate increases These agents prolong the refractory period in atrial and ventricular tissues Propafenone and Flecainide

Answer 41

Class 1C antiarrhythmic used to treat narrow complex tachyarrhythmias usually combined with diltiazem also has mild beta blocking properties

Answer 42

Class 1C antiarrhythmic potent negative inotropic properties Side effects include GI, but not commonly seen Rarely used in veterinary medicine Monitor heart rate, blood pressure and ECG when administering

Answer 43

Beta-adrenergic antagonists or beta-blockers are the most used cardiovascular drugs. Must be cognizant of animals' underlying disease when prescribing. Beta-blockers contraindicated in patients with evidence of sinus nodal dysfunction, AVN conduction disturbances, pulmonary disease or CHF (must be evaluated for fluid retention and condition must be stabilized before implementing beta-blockade). Reduces heart rate and myocardial oxygen demand and increases atrioventricular conduction time. Inhibits pacemaker current I(f) that promotes proarrhythmic depolarization in damaged cardiomyocytes Inhibits calcium current by decreasing tissue cyclic adenosine monophosphate levels ; the magnitude of effects depends on the sympathetic state. Greater effect with higher adrenergic states Beta-adrenergic antagonists slow AVN conduction in SVT by slowing sinus discharge rate in inappropriate sinus tachycardia and suppresses ventricular tachycardia that may be exacerbated by increased sympathetic tone. Used to treat supraventricular and ventricular arrhythmias. Also used in HCM to control heart rate and decrease myocardial oxygen demand Can cause hypotension due to decreased heart output. Extremely low dosages must be used with patients with systolic myocardial dysfunction. Because of that, beta blockers are not generally first choice for acute anti-arrhythmic therapy because the amount required is not well tolerated.

Answer 44

Non-selective beta receptor antagonist (targets both beta-1 and 2 receptors). Function: decrease heart rate and contractility. Decrease renin release and peripheral vascular resistance

Answer 45

Class II Antiarrhythmic Short-acting Beta-1 blocker that can help control sympathetically driving ventricular tachycardia . Administered as a CRI on telemetry. Side effects: Negative inotropic effects may be too pronounced in some patients and cause cardiovascular collapse. Requires blood pressure monitoring.

Answer 46

Class II antiarrhythmic. The most common oral beta blocker in small animals. Relative beta 1 selectivity and long half-life compared to propranolol. Water soluble and eliminated by the kidney.

Answer 47

Class II antiarrhythmic. Common oral beta blocker in small animals. Long half-life compared to propranolol. Metabolized and eliminated through the liver.

Answer 48

Block the repolarization of I(k) resulting in prolongation of action potential durations and effective refractory period. Blocks rapid component of I(k) instead of the slow component -- therefore effects are accentuated at slower heart rates rather than at the problematic tachyarrhythmic rates. Puts patients at risk of early afterdepolarization (accounts of proarrhythmic effects of class III AA drugs) - risk is increased in patients with hypokalemia, bradycardia, intact females, increasing age, macrolide antibiotic therapy/other drug therapies

Answer 49

Class III Antiarrhythmic Alpha and Beta blocking properties. Effects on sodium, potassium, and calcium channels. Broadest spectrum exhibiting properties of all 4 AA classes. Makes action potential durations more uniform throughout the myocardium and has the least reported proarrhythmic activity of any of the class III agents. Used for refractory tachyarrhythmias, both atrial and ventricular Significant side effects in dogs, including hepatopathy and anaphylaxis. Monitor heart rate, blood pressure and ECG with administer. Available as oral or injectable. Major drawback: associated with a host of multi-systemic adverse side effects that do not occur with sotalol. Adverse side effects (more common with higher maintenance doses): vomiting, anorexia, hepatopathies, thrombocytopenia Two brands: Cardarone IV, Nextarone

Answer 50

IV formulation of amiodarone Serious side effects attributed to vasoactive solvents in the formulation. Side effects include life-threatening hypotension, anaphylaxis, bradycardia, acute hepatic necrosis, and death.

Answer 51

Premixed aqueous solution of IV amiodarone. No adverse hemodynamic effects of other adverse cllinical effects in healthy research dogs.

Answer 52

Calcium channel antagonist Slow AVN conduction and prolong the effective refractory period of nodal tissue Effects are more notable at faster stimulation rates and in depolarized fibers. Effective in slowing the ventricular response rate to atrial tachyarrhythmias and can prolong AVN's effective refractory period to terminate AVN-dependent tachyarrhythmia. It is mainly indicated to reduce the rate of arrhythmias passing through the AV node, such as supraventricular arrhythmias. Major negative inotropic effects due to interactions with calcium in the smooth muscles. Causes vasodilation Limit amount of calcium available in cardiac contractility. Diltiazem is the most widely used IV antiarrhythmic drug

Answer 53

Class IV antiarrhythmic Calcium channel blocker. Minimal negative inotropic effects. Used in dogs to immediately terminate a severe AVN-dependent tachyarrhythmia or slow ventricular response rate to an atrial tachyarrhythmia. Adverse side effects: hypotension and bradyarrhythmia. Administer IV slowly over 2-3 minutes. Oral diltiazem administered TID.

Answer 54

Class V anti-arrhythmic (other) Effects occur indirectly through the autonomic nervous system by enhancing central and peripheral vagal tone. Used as an antiarrhythmic due to its ability to slow AV conduction time and have parasympathomimetic effects Treats SVT to slow AV nodal conduction and reduce ventricular rate Positive inotrope that will increase cardiac contractility in systolic disease The risk of toxicity manifests as neurological, GI, and cardiac involvement. Predisposed to toxicity if the patient has renal dysfunction, hypokalemia, elderly, chronic lung disease, hypothyroidism.

Answer 55

1st line treatment for torsades de pointes Used to treat hypomagnesemia Administer slowly IV @ 30mg/kg over 5-10 minutes Adverse effects: CNS depress, weakness, bradycardia, hypotension, hypocalcemia and QT prolongation

Answer 56

Used in humans to terminate AVN dependent tachyarrhythmias. No study to date has shown effectiveness in dogs and cats.

Answer 57

Transvenous radiofrequency catheter ablation Permanent pacemaker implantation Implantable cardioverter defibrillators

Answer 58

Identify reentrant circuit or automatic focus for ablation Deliver radiofrequency energy via electrode causing thermal desiccation of small volume tissue to interrupt tachycardia circuit

Answer 59

Manage bradyarrhythmias

Answer 60

experimental in dogs

Answer 61

class of drugs taht block the action of acetylcholine (ACh), a neurotransmitter that sends signals between cells that affect a bodily function. By blocking ACh at synapses in the central and peripheral nervous system, anticholinergics inhibit the parasympathetic nervous system.

Answer 62

Anticholinergic inhibit acetylcholine at muscarinic receptors Clinical effects include increasing heart rate, resolving vagally mediated bradycardia, decreasing GI motility, pupillary dilation, bronchodilation, urinary retention and drying or secretion Most commonly used to treat vagal-mediated bradycardias and toxicities Able to pass the placental barrier.

Answer 63

Anticholinergic inhibit acetylcholine at muscarinic receptors Clinical effects include increasing heart rate, resolving vagally mediated bradycardia, decreasing GI motility, pupillary dilation, bronchodilation, urinary retention and drying or secretion Most commonly used to treat vagal-mediated bradycardias and toxicities Glycopyrrolate is associated with more stable cardiovascular system with fewer arrhythmias Glycopyrrolate has a stronger anti-saliva secretion effect than atropine It does not pass the placental barrier and, therefore, is the agent of choice for pregnant animals.

Answer 64

Loop diuretics Osmotic Diuretics Potassium sparing diuretics Thiazide diuretics Carbonic anhydrase inhibitors Aldosterone Antagonist Aquaretics (new)

Answer 65

Enhanced excretion of retained water, solutes and toxins Promote urine flow decrease urine concentration of solutes and toxins

Answer 66

Oligoanuric acute renal failure decompensated kidney disease Congestive heart failure ascites from liver failure other fluid and electrolyte disorders

Answer 67

Only when fluid retention is caused by an increase in hydrostatic pressure. When vascular permeability is increased, further depletion of vascular volume with diuretics is rarely indicated and often detrimental

Answer 68

May activate RAAS by reducing intravascular volume and ventricular filling and may subsequently decrease tissue perfusion. Therefore, diuresis requires therapeutic monitoring

Answer 69

pressure natriuresis osmotic diuresis

Answer 70

A negative feedback in hypervolemic hypertensive states

Answer 71

Diuretics at the loop of Henle are the most effective because of the large amount of filtrate delivered to this site and the lack of efficient distal reabsorption region.

Answer 72

Elevated plasma osmolality hypovolemia hypotension (lesser extent) nausea increased concentration of angiotensin II

Answer 73

passive mechanism due to abnormal urine concentration of osmotically active solutes such as glucose and sodium

Answer 74

functional renal tubular system medullary concentration gradient of sodium and urea functional ADH receptor system without any one of these factors will result in inappropriate diuresis

Answer 75

Diuretics that work on proximal tubule can modulate a greater bulk of sodium, but their efficacy may be overcome by distal compensatory increases in sodium reabsorption.

Answer 76

Diuretics operating on distal tubule may be limited by small amount of sodium reaching distal tubule

Answer 77

hyperosmolality causes water shift from the intracellular fluid compartment to extracellular space, causing ECF expansion Used to contract ICF in cases with cerebral edema associated with an increase in ICF and elevated intracranial pressure Contraindicated for patients in or at risk of heart failure. Effective in patients with anuric or oliguric rental disease, cerebral edema and increased intraocular pressure eg. Mannitol

Answer 78

osmotically active non reabsorbed sugar alcohol filtered by the glomerulus; does not undergo tubular reabsorption, thereby increasing tubular flow rate and osmotic diuresis An increase in tubular flow rate reduces urea absorption, resulting in increased urinary clearance and serum urea concentration. Potential benefits of mannitol: Prostaglandin-induced renal vasodilation reduced tendency of erythrocytes to aggregate reduced renal vascular congestion reduced hypoxic cellular edema protection of mitochondrial function reduced oxidative damage renoprotectant when administered before toxic or ischemic event *No data supports above benefits in renal failure cases At high doses, mannitol can cause renal vasoconstriction and tubular vacuolization Use cautiously with oliguric animals to avoid volume overload, hyperosmolality and further renal damage.

Answer 79

Clinical application of carbonic anhydrase inhibitors - mainly used to treat elevated intraocular pressure in glaucoma. Work by suppressing the activity of carbonic anhydrase, an enzyme in red blood cells that converts carbon dioxide into carbonic acid and bicarbonate ions. CAIs can reduce secretion of H+ ions by the kidney tubule and can also impair the reabsorption of sodium, chloride and bicarbonate. eg. Acetazolamide Carbonic anhydrase also located on other organs. Blockade of ocular and brain CA decreases the production of aqueous humor and CSF. Blockade of red blood cell CA hampers carbon dioxide transport Gastric CA - minimally affected by inhibitors.

Answer 80

Carbonic anhydrase inhibitor Function: diuretic Inhibits mostly the type II (cytoplasmic) and IV(membrane) proximal tubular carbonic anhydrases, decreasing the reabsorption of sodium bicarbonate. Results in metabolic acidosis and natriuresis - minimal and self-limiting because progressively less bicarbonate is filtered as the proximal tubule becomes less responsive to carbonic anhydrase inhibition and the distal sodium reabsorption increases to compensate for the proximal losses.

Answer 81

Binds to and inhibits Na+-K+-2Cl- cotransporters on the apical membrane of epithelial cells of the thick ascending loop of Henle. Inhibition of reabsorption of both Na and Cl, ions remain in the tubular lumen and water follows, resulting in diuresis and increased Na secretion ○ High sodium concentration later in the nephron results in increased sodium and potassium exchange, which leads to increased potassium secretion as well ○ Increased calcium secretion also occurs ○ Also believed to decrease renal vascular resistance and increase renal blood flow Prototypical loop diuretic: furosemide Torsemide

Answer 82

Loop diuretic Improves renal parenchymal oxygenation by decreasing the energy expenditure of the secondary active Na-K-2Cl transporter Mannitol + furosemide > synergistic in inducing diuresis in dogs with acute renal failure Relative short half-life: 1-1.5 hours in dogs > can result in intermittent rebound sodium retention with loss of efficacy. most commonly used in patients in heart failure.

Answer 83

potent loop diuretic of pyridine-sulfonylurea class longer half-life (8 hours) higher bioavailability (80%-100%) strong diuretic effect than furosemide Large scale study - effective in dogs with mitral valve disease, but high rate of renal adverse events. Additional benefits observed in other species: vasodilation, improved cardiac function, reduction of myocardial remodeling, mineralocorticoid-receptor blockade with anti-aldosterone effect - has not been shown in small animals

Answer 84

exert their action by inhibiting the NaCl cotransporter on distal tubule. Mainly used for anticalciuretic properties to prevent calcium-containing uroliths Managing CHF in conjunction with other diuretics treating ascites associated with right-sided heart failure also used for treating polyuria of diabetes insipidus by inducing a mild hypovolemia and increasing proximal sodium conservation. eg. Hydrochlorothiazide

Answer 85

Antagonize aldosterone by binding to its receptor in the late distal tubule and the collecting duct increases sodium, calcium and water excretion and decreases potassium loss e.g. Spironolactone and eplerenone

Answer 86

concurrent hypernatremia, severe hypokalemia

Answer 87

Aldosterone antagonist potassium sparing diuretic Best used in cases of hyperaldosteronism Main clinical applications in liver and heart failure. Also used as an antihypertensive in hyperaldosteron cases. Usually, it is in combination with a more efficient loop diuretic. Also seems to have a positive effect on myocardial remodeling and the reduction of cardiac fibrosis Commonly added to other diuretics to reduce their potassium-wasting effects Main adverse effect: development of hyperkalemia

Answer 88

Inhibit sodium reabsorption in the distal tubule and the collecting duct; suppressing the driving force for potassium secretion. Only weak diuretic and natriuretic properties Mostly used to counterbalance potassium-wasting effects of proximal diuretics. e.g. Amiloride and triamterene

Answer 89

New class of diuretics that antagonize the vasopressin V2 receptor in the kidney and promote solute-free water clearance Vaptans - vasopressin receptor antagonist Clinical use: free water rention in hypervolemic hyponatremia or normovolemic hyponatremic drugs: conivaptan, tolvaptan and mozavaptan Not used in small animals

Answer 90

Function: positive inotropic and vasodilatory effects Phosphodiesterase III inhibitor Calcium sensitization Used to treat congestive heart failure

Answer 91

increase contractility via increasing binding affinity to the regulatory site on troponin C for calcium sensitizes the myocyte contractile apparatus to calcium without increasing the amount of calcium within the cell. Pimobendan is not dependent on catecholamines

Answer 92

increase contractility by increasing intracellular calcium levels. PDE III inhibition increases cyclic adenosine monophosphate (cAMP), which in turn increases cAMP-dependent protein kinase. Increase in calcium sequestration during diastole and increase in calcium influx during systole - both contribute to positive inotropy PDE III and PDE V are found in vascular smooth muscle. Inhibition of PDE III and PDE V increases intracellular cAMP and cGMP - which facilitates calcium update through intracellular storage sites. Results in reduction of available calcium for contraction > greater vascular smooth muscle relaxation.

Answer 93

undergoes hepatic demethylation

Answer 94

Pimobendan is highly protein bound with greater than 90% bioavailability. Maximal cardiac effects at 2-4 hours following oral administration and persists up to 8 hours.

Answer 95

FDA approved to treat CHF with myxomatous mitral valve degeneration or DCM

Answer 96

generally well tolerated but may cause GI upset - inappetence, vomiting, diarrhea and lethargy

Answer 97

Angiotensin-converting enzyme inhibitor Angiotensin receptor blocker aldosterone antagonist calcium channel blocker alpha 1 antagonist beta antagonist arteriolar vasodilator

Answer 98

Family of drugs designed to disrupt the renin-angiotensin-aldosterone system (RAAS). Medications function by inhibiting the conversion of angiotensin I to angiotensin II. ACE inhibitors can decrease proteinuria promote vasodilation, venodilation and reduction in plasma volume with reduction in systolic blood pressure ACE inhibitors can cause decreased metabolism of vasodilatory agent bradykinin --> further reduction in vascular tone Clinical application of ACE inhibitors where systemic hypertension is caused by known or suspected increase in RAAS - most commonly related to chronic kidney disease and or glomerular disease. Most commonly considered 1st line treatment for dogs (not cats). Generally well tolerated. Biggest concern: potential to worsen glomerular filtration rate and renal function through preferential dilation of the efferent arteriole (thereby reducing glomerular filtration pressure) e.g. Enalapril, benazepril, lisinopril

Answer 99

Angiotensin Converting Enzyme Inhibitor

Answer 100

Angiotensin Converting Enzyme Inhibitor

Answer 101

Angiotensin Converting Enzyme Inhibitor

Answer 102

Class of drugs that block angiotensin II from its receptor. **Does not affect the metabolism of bradykinin** ARBs can decrease proteinuria promote vasodilation, vasodilation and reduction in plasma volume with a reduction in systolic blood pressure Side effects: similar side effects as ACEi; avoided or cautiously used in patients with severe dehydration or azotemia. e.g. Telmisartan, losartan

Answer 103

Angiotensin receptor blocker

Answer 104

decrease calcium influx into cardiac tissues (antiarrhythmic properties) and vascular smooth muscles (antihypertensive properties) May cause reflex bradycardia Other side effects could include weakness, lethargy, decreased appetite CCBs promote preferential afferent arteriolar dilation over the efferent arteriole, which increases intraglomerular pressure, which could damage the glomerulus and worsen proteinuria.

Answer 105

Belongs to the dihydropyridines family Calcium channel blocker Relative selectivity for vascular smooth muscles so promotes vasorelaxation and reduces systemic vascular resistance An associated decrease in blood pressure may trigger reflex tachycardia. First-line antihypertensive of choice for managing SHT in cats

Answer 106

Alpha 1 adrenergic antagonist used in hypertensive crisis, specifically as rescue therapy during pheochromocytoma surgery

Answer 107

Alpha 1 adrenergic antagonist commonly used to stabilize patients with pheochromocytoma prior to surgical intervention

Answer 108

Any drug specifically used to cause constriction to blood vessels increase cardiac afterload, produce vasoconstriction, increase vasomotor tone and systemic vascular resistance most common pathway is alpha 1 adrenergic agonism

Answer 109

Any drug specifically used to increase cardiac contractility most common pathway to achieve this is beta 1 adrenergic agonistm

Answer 110

decrease cardiac contractility

Answer 111

Catecholamine and sympathomimetic Primary receptors: dopaminergic, beta-1 and alpha 1 adrenergic agonist different doses = different effects Low range - stimulate urine production in oliguiric or anuric AKI Intermediate range: predominantly positive inotropic effects High doses: vasoconstriction/increase in vascular resistance Effects: increases renal blood flow improves inotropy increases heart rate increases systemic vascular resistance increases blood pressure increases cardiac out put Deliver as a CRI Side effect: arrhythmias, tachycardia, hypertension Continuous ECG, BP monitoring recommended

Answer 112

Sympathomimetic receptors: Beta-1 and Adrenergic-2 agonist Effects: improves inotropy +/- increase in heart rate Increase in cardiac output +/- increase in blood pressure decrease systemic vascular resistance Deliver as a CRI Side effects: arrhythmias, tachycardia, hypertension, bradycardia Monitoring: ECG/BP continuous

Answer 113

catecholamine and sympathomimetic Receptors: Alpha-1 and beta 1 adrenergic agonist Effects: increase in inotropy decrease in heart rate increase in systemic vascular resistance increase in blood pressure Deliver as a CRI Side effects: arrhythmias, hypertension, bradycardia, excessive vasoconstriction

Answer 114

Catecholamine Receptors: alpha 1 and beta 1 adrenergic agonist Lower doses have predominantly beta agonist effect: vasodilation, bronchodilation, increased cardiac contractility and cardiac output, increased heart rate higher doses: more alpha 1 adrenergic effects: vasoconstriction Used to treat anaphylaxis Side effects: arrhythmia Monitoring: continuous ECG/BP Deliver as IV bolus, CRI, IM or intratracheally

Answer 115

sympathomimetic receptor: alpha-1 adrenergic agonist Effects: decrease in heart rate increase in systemic vascular resistance (marked vasoconstriction) increase in blood pressure May improve blood pressure, but the increase in cardiac afterload may decrease stroke volume and cardiac output Deliver as a bolus or CRI Side effects: arrhythmia, hypertension, bradycardia, excessive vasoconstriction

Answer 116

Sympathomimetic receptors: beta-1 agonist, and alpha 1 adrenergic agonist effects: increase inotropy increase in blood pressure increase in cardiac output +/- Heart rate increase in systemic vascular resistance deliver as a bolus (short duration of effect) or CRI Side Effects: arrhythmias, tachyphylaxis (reduced sensitivity after repeated administration), hypertension, bradycardia, tachycardia

Answer 117

Non-adrenergic hormone AKA anti-diuretic hormone receptors: V1 vasopressin Agonist effects: increase systemic vascular resistance increase blood pressure Increase in cardiac afterload may decrease stroke volume and cardiac output, resulting in decrease oxygen delivery to tissue Alternative or conjunctive therapy to epinephrine in CPCR More effective than epinephrine when patient in acidosis. deliver as a bolus or CRI Side effects: arrhythmias, hypertension, bradycardia, excessive vasoconstriction

Answer 118

- increases in plasma osmolality - central chemoreceptors detect systemic osmolality. Peripheral chemoreceptors in mesenteric and portal veins detect changes in osmolality of ingesta. Afferent impulses ascend via vagus nerve to stimulate vasopressin release. Plasma tonicity sened by hypothalamus to stimulate more vasopressin release. - decreases in blood pressure - shifts osmolality. Baroreceptors in left atrium, aortic arch and carotid sinus sense drops in blood pressure and circulating blood volume. Allows for release of disinhibition of vasopressin release. - drop in circulating blood volume

Answer 119

glucocorticoids low dose opioids atrial natriuretic factor GABA neurotransmitter

Answer 120

found primarily on smooth muscle cells Activation of voltage gated calcium channels, increases intracellular calcium levels allowing for vasoconstriction. V1-R in platelets - facilitates thrombosis because of intracellular calcium V1-R in kidneys decrease blood flow to inner medulla and limit anti-diuretic effects; selective cause contraction of efferent arterials to increase GFR There are species variations in V1R locations.

Answer 121

Found primarily on basolateral membrane of distal tubule and principle cells of cortical and medullary rental collecting duct triggers fusion of aquaporins with plasma membrane of collecting duct --> increasing water absorption. stimulates release of platelets from bone marrow and enhances release of Von Willebrand's factor and Factor VIII from endothelial cells

Answer 122

regulating fast shuttling of aquaporin-2 to cell surface stimulates synthesis of RNA encoding aquaporin 2 hereditary nephrogenic diabetes insipidus have V2-R gene mutations

Answer 123

half life is 24 minutes cleared by renal excretion and metabolized by tissue peptidases

Answer 124

contraction of bladder and gallbladder smooth muscles increase peristalsis decrease in gastric secretions increase in GI sphincter pressure Local irritation at injection site. If extravasated, may cause skin necrosis May increase liver enzymes and bilirubin levels decrease platelet count hyponatremia anaphylaxis/urticaria bronchospams abdominal pain hematuria water intoxication reported with high dose treatment of diabetes

Answer 125

selective for V1R prolong duration - 6 hours half life Used to manage hemorrhagic gastroenteritis increase adverse effects - peripheral cyanosis/ischemia (use with caution)

Answer 126

V1R agonist found to reduce risk of coronary ischemia less adverse effects on mesenteric blood flow and gastric mucosal perfusion effective substitute for maintaining MAP, reducing vascular leak, edema formation and shortening duration of shock. Comparative study with norepi -> no improved outcome

Answer 127

synthetic vasopressin intranasal and injectable form binds primarily to V2R more potent antidiuretic and procoagulant

Answer 128

gram-positive cocci arranged in chains

Answer 129

It can cause pharyngitis, glomerulonephritis, and rheumatic fever in humans. It rarely causes illness in dogs and cats, although dogs can carry the organisms.

Answer 130

rare causes of illness in healthy dogs and cats

Answer 131

common resident microflora and are the cause of most streptococcal infections in dogs and cats. Streptococcus canis is the most common.

Answer 132

The main source of infection in anal mucosa in dogs. May be found in cats in abscesses, pyelonephritis, sinusitis, arthritis, metritis or mastitis In dogs, it may be the cause of nonspecific infections including wounds, mammary tissues, urogenital tract, skin and ear canal. May cause toxic shock syndrome in dogs. Tx: Penicillin-G and ampicillin are effective for most infections

Answer 133

Enterococcal Commensal bacteria that inhabit the alimentary tract of humans and animals Most commonly see in post op wounds and urogenital infections.

Answer 134

Gram positive bacteria, developing resistance to antimicrobials. cephalosporins, penicillins and fluoroquinolones decreasing in effectivness.

Answer 135

significant cause of morbidity and mortality in critically ill patients

Answer 136

known to be toxic Induces proinflammatory responses and endothelial dysfunction harmful effects of endotoxin include vasodilation, enhanced vascular permeability, tissue destruction, and activation of coagulation pathways

Answer 137

Stimulates the chemoreceptor trigger zone to induce emesis as a non-selective dopamine agonist Side effects: Failure to produce emesis, refractory vomiting, nausea, sedation Adverse sedative effects can be reversed with an opioid agonist such as naloxone

Answer 138

Induces emesis Thought to occur through the stimulation of the chemoreceptor trigger zone at least in part through the area of postrema of the medulla oblongata Concerns include sedation, hyperglycemia, bradycardia, increased systemic vascular resistance, and increased cardiac afterload. Drug: dexmeditomidine

Answer 139

Alpha-2 adrenergic agonist

Answer 140

Alpha-2 adrenergic agonist

Answer 141

most common include hydrogen peroxide, syrup of ipecac, and salt paste syrup of ipecac no longer used due to potential for abuse and fatal cardiac arrhythmia. Salt paste no longer clinically used due to risk of hypernatremia and questionable efficacy Hydrogen peroxides: irritate oral, esophageal and gastric mucosa

Answer 142

Acepromazine, chlorpromazine and prochlorperazine Reduce emesis through blockade of dopamine receptors in CRTZ and emetic centers No longer used because of potential side effects and availability of more effective agents Produce an alpha-1 adrenergic antagonist which causes systemic vascular resistance and vasodilation; can result in hypotension

Answer 143

Prokinetic Dopamine and serotonin antagonist and cholinergic agonist Increases lower esophageal sphincter tone, facilitates gastric emptying short half-life, thus usually prescribed as a CRI contraindication: mechanical obstructions in the GI tract and intussusceptions

Answer 144

Serotonin (5-HT3) Antagonist Block serotonin receptors in the CRTZ and peripherally Appear to be more effective than phenothiazine and metoclopramide Side effects are rare

Answer 145

Neurokinin-1 (NK) antagonist Blocks substance P at vomiting center in the brain

Answer 146

Omeprazole, pantoprazole, esomeprazole Inhibits Na/K ATPase pump activity Recommended treatment for acid suppression; controls proton deposition in the gastric lumen and hydrochloric acid secretion

Answer 147

Famotidine, ranitidine, cimetidine H2 blockers Specific antihistamines that reduce the action of histamine at histamine receptors on gastric parietal cells; reduce stomach acid

Answer 148

Sucrose sulfate-aluminum complex Binds to locally injured GI lining and creates a physical barrier Promotes bicarb production and may increase production of prostaglandin E2 Commonly used to treat GI or duodenal ulcers Can also be beneficial in esophageal strictures

Answer 149

Synthetic prostaglandin E1 analogue It improves gastric blood flow, decreases gastric acid production, increases mucus production and bicarb secretion, and promotes cell turnover. Specifically used to help prevent NSAID-induced GI injury and ulceration Also has effects on myometrial contraction Wear gloves when handling

Answer 150

Bronchodilators and enhance mucus clearance via mucociliary system Relaxes smooth muscle in respiratory passageways May also cause vasodilation in muscles. Commonly used to trat asthma in cats, chronic bronchitis in dogs or hyperkalemia drugs: terbutaline, albuterol, salmeterol Most common side effects: tachycardia, increased cardiac contractility and arrhythmia

Answer 151

beta-2 adrenergic agonist Bronchodilator Commonly used to treat asthma in cats, chronic bronchitis in dogs or hyperkalemia Administered orally or parenterally Common side effects are tachycardia, increased cardiac contractility and arrhythmia

Answer 152

beta-2 adrenergic agonist Bronchodilator administered via inhaler Common side effects are tachycardia, increased cardiac contractility and arrhythmia I.e. albuterol toxicity

Answer 153

bronchodilator Inhibit phosphodiesterase and blocking adenosine believed to inhibit leukotriene synthesis and reduce inflammation Narrow therapeutic range Occasionally used to treat pulmonary hypertension and tracheal collapse. adverse effects are tachycardia, arrhythmia and GI signs examples of Methylxanthines: Caffeine and theobromine - toxic to animals

Answer 154

Antihistamine Inverse agonist of H1 histagenergic receptor (produces opposite effect of histamine since its an inverse agonist) influences muscarinic acetylcholine receptors, sodium channels and potentially reuptake of serotonin Predominately used for: - reducing signs of acute allergic reactions - treat increase capillary permeability secondary to histamine release. - reducing symptoms of histamine release from Mast cell tumors. - crosses the blood brain barrier --> affect CNS; cause sedation or excitement (rare in dogs and cats) Do not administer SQ because of irritating effects.

Answer 155

antihistamine Used for patients with vestibular disease Antiemetic and motion sickness

Answer 156

antihistamine serotonin agonist Used as a mild appetite stimulant Can also be used to treat serotonin syndrome --> evidence to support efficacy is limited

Answer 157

antihistamine Has an effect on serotonin, adrenergic, dopamine and muscarinic receptors weak appetite stimulant and antiemetic

Answer 158

nonsteroidal anti-inflammatory drug blocks platelet cyclo-oxygenase (COX)1 which causes inhibition of thromboxane A2 (TXA2) Effect is irreversible Primarily used to treat hypercoagulable states or states of increased platelet reactivity

Answer 159

Thienopyridine class drug Blocks adenosine diphosphate (ADP) induced platelet aggregate through binding the platelet P2Y12 receptor Primarily used to treat hypercoagulable states or states of increased platelet reactivity Does not remove already formed blood clots

Answer 160

Naturally occurring - stored within mast cells and released into vasculature at sites of tissue injury Drug - Unfractionated heparin: heparin sulfate can be reversed using protamine sulfate Drug - low molecular weight heparins: Dalteparin and enoxaparin Does not dissolve preexisting blood clots

Answer 161

Low molecular heparin Associated with fewer bleeding events, more predictable absorption and can be given less frequently than UFH Inhibits factor Xa Incompletely reversed by protamine sulfate

Answer 162

Unfractionated heparin Binds to antithrombin and inhibits factors IIA, IXa, Xs, XIa, and XIIa can be reversed using protamine sulfate

Answer 163

Rivaroxaban and apixaban Does not require antithrombin for factor Xa inhibition and clinical effects Does not dissolve blood clots that have already formed

Answer 164

Trade name: Xarelto Direct Factor Xa inhibitor Oral anticoagulant used to prevent or treat thrombosis in high risk patients Contraindicated in patient with uncontrolled pathologic bleeding, severe hepatic disease, hepatic disease associated with coagulopathy or with significant renal impairment

Answer 165

Drugs: streptokinase, urokinase, tissue plasma activator (t-PA) Not widespread in vetmed Should be administered as early as possible to be most effective contraindicated or inappropriate in situations of known coagulopathy, states of active bleeding, cardiac thrombi, neoplasia that invades the vasculature and infective endocarditis Complication associated with thrombolytic agents: Bleeding

Answer 166

1) 5-lipoxygenase (LOX) 2) Cyclo-oxygenase (COX)

Answer 167

Arachidonic acid is released from the cell membranes, triggered by phospholipase A2

Answer 168

Arachidonic acid is metabolized into leukotrienes by LOX

Answer 169

arachidonic acid is metabolized into prostaglandins, prostacyclin and thromboxanes by COX

Answer 170

COX 1 and COX2

Answer 171

Primarily responsible for basal prostaglandin production for normal homeostatic processes within the body, including gastric mucus production, platelet function, and, indirectly, hemostasis.

Answer 172

found at sites of inflammation and some basal production of constitutive prostaglandins. Ideally, selective inhibition of prostaglandins produced primarily by COX-2, however currently there are no pure COX2 inhibitors.

Answer 173

Present in phospholipid portion of plasma membrane. It is an inflammatory mediator which causes vasodilation and vasoconstriction. Inflammation = vasodilation blood coagulation = vasoconstriction Phospholipase A2 releases Arachidonic Acid. Arachidonic Acid can then be broken down to prostaglandins or the leukotriens by COX or LOX respectively.

Answer 174

steroids Therefore steroids are anti-inflammatory

Answer 175

NSAIDs inhibit COX enzyme, which inhibits formation of prostaglandins. NSAIDs are metabolized by the liver and excreted by the kidneys. Give with food. Adverse side effects: Because prostaglandins play a role in maintaining GI mucosal integrity, some of the side effects of NSAIDs are gastroenteritis, ulceration, and potentially GI perforation. Use cautiously in patients with hypotension, hypovolemia, pre-existing renal disease (due to increased potential for renal vascular vasoconstriction which could lead to worsening of renal insufficiency) use with caution perioperatively because of decreased platelet function --> may increase risk of operatie hemorrhage.

Answer 176

Produced when lipoxygenase acts on arachidonic acid. Lipid-like bronchoconstrictors that are released during the inflammatory response. Asthma is treated with inhaled and oral medications that include beta-2 adrenergic agonist anti-inflammatory drugs and leukotriene antagonist

Answer 177

Produced when cyclooxygenase (COX) acts on arachidonic acid. Many functions including: Inflammation, Reproduction, gastric secretions, blood clotting Two types of prostaglandins depending on tissue type. Location: Platelets --> Thromboxane Location: Endothelium --> Prostacyclin Thromboxane -->vasoconstriction +bronchoconstrictor = procoagulation Prostacyclin --> vasodilation + prevent platelet aggregation = anticoagulation **Prostaglandins protect GI mucosa from environment of stomach**

Answer 178

Vasoconstrictor increases platelet aggregation bronchoconstrictor

Answer 179

"keeps blood cyclin" 1. vasodilator 2. decreases platelet aggregation

Answer 180

1. Promote fever 2. promotes pain

Answer 181

Inhibits Arachidonic acid prostaglandins and leukotriens

Answer 182

tissue injury thrombin bradykinin angiotensin II (stimulates vasoconstriction) epinephrine (stimulates vasoconstriction)

Answer 183

Rimadyl, Carprovet, Truprofen NSAID

Answer 184

Previcox or Equioxx NSAID

Answer 185

Deramaxx NSAID

Answer 186

Galliprant NSAID

Answer 187

Onsior NSAID

Answer 188

Adrenal gland, gonads and placenta

Answer 189

Glucocorticoids and Mineralcorticoids

Answer 190

Increase carb, protein and fat metabolism growth (specifically in utero) increase contractile activity of left ventricle signal kidneys to reabsorb sodium inhibit activity of cells that are used to promote connective tissue production alter turnover of bone stop GI from absorbing calcium and promote calcium excretion from kidney Inhibit formation of prostaglandins and bradykinins -> inhibit inflammation suppress white blood cells (lymphocytes and eosinophils)

Answer 191

1. optimize antimicrobial use 2. minimize the duration of prescription 3. Re-escalating antimicrobial therapy when culture and susceptibility results have returned

Answer 192

1. endocarditis 2. prosthetic implants 3. persistent neutropenia

Answer 193

only efficacious when [drug] in plasma is above the MINIMUM INHIBITORY CONCENTRATION (MIC) for that pathogens. Note: in critically ill patients, ft>MIC may be 100%

Answer 194

percentage of time drug concentration is above the minimum inhibitory concentration.

Answer 195

usually bind irreversibly to their target their efficacy is usually predicted by comparing the maximum concentration (Cmax) to the MIC) Critical illness Cmax:MIC should be >8

Answer 196

Depending on if the antimicrobial is hydrophilic or lipophilic Volume of distribution of the antimicrobial will be affected e.g. If the antimicrobial is hydrophilic, the net effect of volume distribution is higher, decreasing [antimicrobial] in plasma --> decreasing [antimicrobial] in target tissue

Answer 197

AKI --> elimination via kidney is decreased therefore fT>MIC is increased. However, must consider risk of toxicity is increased due to drug accumulation

Answer 198

Augmented renal clearance --> increased removal of substrate by the kidneys Antimicrobials may remain at subtherapeutic levels resulting in worsening patient outcomes Incidence not studied in VetMed.

Answer 199

Antimicrobial clearance may be decreased for hepatically metabolized drugs. (Usually takes reduction of 90% of liver) --> therefore patients in fulminant liver failure = consider dose reduction Generally no change needed if biochem panel shows hepatic dysfunction.

Answer 200

Penicillins cephalosporin carbapenam monobactam

Answer 201

beta lactam ring effects exerted by disrupting the synthesis of the cell wall during bacterial replication by binding to the "penicillin-binding proteins" (PBP) when beta lactam ring binds to PBP --> results in degradation of cell wall and imparis synthesis of new cell wall leaving bacteria exposed to local environment and resulting in bacterial lysis Beta lactams are bactericidal

Answer 202

alterations to PBP development of antimicrobial efflux pumps changes to porins in bacterial cell wall inactivation by beta lactamases --> can be acquired or intrinsic resistance

Answer 203

Beta-lactam Gram positive and anaerobic coverage Minimal gram negative coverage Able to kill enteric flora which can cause vomiting and diarrhea. C

Answer 204

Excreted unchanged in urine highly effective in UTI

Answer 205

benzylpenicillin (Pen-G), phenoxymethylpenicillin (penicillin V), procaine penicillin, benzathine penicillin (pen B)

Answer 206

Beta-lactamase resistant Most effective against gram positive aerobes and anaerobes.

Answer 207

Beta-lactam 5 generations: grouped into generations based on their relative spectrum of activation lower the generation, the better gram positive spectrum the higher the generation, the better gram negative coverage more stable against beta lactamases than penicillins

Answer 208

beta-lactam effective against variety of gram positive limited activity against anaerobic bacteria. drugs: cefazolin, cephalexin, cefadroxil

Answer 209

moderate gram positive and gram negative increase spectrum against anaerobes drugs: cefoxitan, cefotetan, cefuroxime

Answer 210

Broad spectrum activity with resistance to many beta lactamases relies on normal plasma albumin for effective therapeutic serum levels Good penetration of CSF drugs: ceftiofur, cefotaxime, ceftazidime, cefovecin(Convenia - 1 injection for 14 days), cefpodoxime (only drug in this gen available as oral medication)

Answer 211

excellent activity against enteric organisms drugs: cefepime, cefpirome and cefquinome

Answer 212

only 1 drug: ceftaroline spectrum of action similar to 3rd gen - good gram positive coverage retains efficacy to Staphylococcus spp. that are resistant to methicillin

Answer 213

Drug: Aztreonam Gram Negative coverage Not used much in vetmed

Answer 214

broad spectrum resistant to many beta lactamases considered top tier antimicrobial goup and should not be used empirically Drugs: imipenem, doripenem, ertapenem and meropenem

Answer 215

Carbapenem beta lactam antimicrobial nephrotoxic - drug degrades in renal tubule by kidney enzyme dehydropeptidase 1 Administer with Cilastatin to prevent degradation associated with seizures in humans

Answer 216

Carbapenem beta lactam antimicrobial not nephrotoxic

Answer 217

clavulanic acid sulbactam tazobactam bind irreversibly to beta lactamases so when administered with a beta lactam, the beta lactam can bind to bacterial PBP.

Answer 218

Toxicity to beta lactam group considered very low. Potential adverse reactions: Type 1 hypersensitivity from urticaria to anaphylaxis - frequency unknown in small animals (occurs in 0.7%-10% of people receiving penicillin Type 2 hypersensitivity can also occur -- hemolytic anemia, thrombocytopenia and neutropenia reported Type 4 reactions usually manifest as cutaneous disease Can rigger immune-mediated reactions such as IMHA Can kill neric flora which cause nausea, vomiting, diarrhea High doses can result in seizures and other neurologic diseases (more likely if brain diseases already present)

Answer 219

Antimicrobial used to treat gram negative infections Rely on aerobic bacterial metabolism parenteral administration only requires monitoring of renal function Exhibit synergistic bactericidal effects when administered in combination with beta lactams

Answer 220

Inhibit bacterial protein synthesis by binding to ribosome resulting in faulty protein. further synthesis increases aminoglycoside uptake by the cell which eventually leads to complete cessation of ribosomal activity. Stage 1: outer bacterial lipopolysaccharide membranes are negatively charged while aminoglycoside is positively charged. Ionic binding allows aminoglycoside entry into cell and increase cell wall permeability Stage 2: Energy dependent phase Faulty protein synthesis inserted into cytoplasmic membrane of bacteria allowing for more aminoglycoside entry (slow process and relies on ATP hydrolysis --> therefore reduced activity in anaerobic conditions). This stage can be blocked by inhibitors of oxidative phosphorylation or electron transport Stage 3: Aminoglycoside accumulate quickly after nonspecific membrane channels inserted --> increasing rate of mistranslation of protein synthesis

Answer 221

1. enzymatic mutation of aminoglycoside molecules 2. target modification in ribosomal 30s subunit structure 3. increase in aminoglycoside efflux 4. intrinsic resistance to anaerobes

Answer 222

Absorption: water soluble; poorly absorbed from GI tract therefore must be administered parenterally Distribution: primarily extravascular - can reach bone, synovial fluids, peritoneal fluid (especially if inflammation present). Distribution to bronchial secretions is good. Does not penetrate cell membranes well because of positive charge. Not recommended for CNS, eyes or prostate. Elimination: primarily through kidneys unchanged by glomerular filtration.

Answer 223

Aminoglycosides readily taken up by cells in proximal tubules and in ears 5-15% will suffer aminoglycoside induced nephrotoxicity (excreted through kidneys) Nephrotoxicity: dose dependent majority of aminoglycoside is excreted but small amount is absorbed by renal tubules Necrotic cells slough into tubular lumen which can result in obstruction Underlying renal dysfunction predisposes patient to aminoglycoside induced nephrotoxicity Often damage is reversible if caught early. Ototoxicity: hair cells update drug resulting in cell death and inflammation dose and duration dependent Ototoxicity is not reversible Neuromuscular blockade Rarely reported, but can be severe enough to cause respiratory depression @ high doses - calcium release impaired at level of neuromuscular junction --> hypocalcemia. Concurrent use of neuromuscular blockade medications or myorelaxants may augment effets.

Answer 224

Amikacin Gentamicin sulfate Tobramycin sulfate neomycin

Answer 225

aminoglycoside Monitor for casts in urine and increases in BUN/Creat dosage may need to be adjusted in critically ill patients can be administered IV, IM, SQ q 24 hrs

Answer 226

Aminoglycoside Monitor for casts in urine and increases in BUN/Creat Can be administered IV, IM, SQ, q 24 hours

Answer 227

Amino glycoside Monitor for casts in urine and increases in BUN/Creat Can be administered IV, IM, SQ q24 hours

Answer 228

Aminoglycoside Used to treat hepatic encephalopathy Minimal GI absorption administer PO q 6-12 hrs

Answer 229

synthetic antimicrobials Inhibit bacterial DNA gyrase which prevents bacterial DNA synthesis, replication and division, resulting in cell death Bactericidal Widest spectrum against gram-negative bacteria Incomplete effectiveness against gram-positive and anaerobic bacteria RESISTANCE TO FLUOROQUINOLONES CAN DEVELOP DURING THE COURSE OF THE TREATMENT

Answer 230

hepatic metabolism and excreted in bile +/- urine either unchanged or as metabolites Most are eliminated by the kidneys Half-life depends on renal elimination and dose

Answer 231

increasing rate of resistance attributed to widespread use of fluoroquinolones Use of fluoroquinolones can lead to development of resistance to other antimicrobial classes Fluoroquinolones should not be used as 1st line treatment. (exception - pyelonephritis, lower respiratory tract infections, bacterial prostatitis, hepatobiliary infections).

Answer 232

GI upset: V/D, nausea, abdominal cramping Neurologic: rapid administration risk CNS adverse effects including seizures It may lower the seizure threshold; therefore, do not use or use it with extreme caution in patients with seizure disorders. Juveniles: cartilage defects - not recommended in growing animals retinopathy: irreversible blindness in cats Rapid IV administration may result in histamine release in dogs Can chelate with positively charged ions - contains beta-keto acid group that can bind to and chelate with positively charged ions; most profoundly seen with aluminum and copper, but can also happen with magnesium and calcium Cardiovascular signs can result in hypotension, bradycardia, prolonged QT Rare reports of fluoroquinolones used in patients with necrotizing fasciitis resulted in activating bacteriophage, rapid bacterial cell lysis, and release of bacteriophage superantigen and the potential sequelae of toxic shock syndrome.

Answer 233

2nd fluoroquinolone only one available as injectable for dogs and cats generally safe, though adverse effects can be permanent Adverse effects can include: - blindness in cats - cartilage defects in juvenile animals Max dose in cats if 5mg/kg q24hrs primary metabolite of enrofloxacin is ciprofloxacin.

Answer 234

2nd gen fluroquinolone longest post-antibiotic effect and half-life No clinical trials support the translation of long half-life to superior antimicrobial efficacy.

Answer 235

3rd gen fluoroquinolone Labeled for use in cats 12 weeks +, off-label for dogs (use in dogs associated with bone marrow suppression) broad spectrum activity including many anaerobic bacteria High potency with lower MIC values when compared with other fluoroquinolones

Answer 236

2nd gen fluoroquinolone not labeled for veterinary use Significantly higher doses needed in dogs than in humans and even so does not always achieve desired serum levels

Answer 237

4th gen fluoroquinolones improved activity against gram-positive and gram-negative only used in human medicine

Answer 238

nitromidazole antimicrobial Indicated to treat most gram-positive anaerobic and all gram negative anaerobic organisms At higher dosages - effective against protoozoal diseases (giardia, amebiasis, trichomoniasis); however higher doses associated with CNS adverse effects Concentration dependent Within the bacteria: reduced and incorporates into bacterial DNA causing loss in helical structure inhibits nucleic acid synthesis results in cell death Bactericidal

Answer 239

Good oral bioavailability Excellent tissue distribution with good penetration to BBB and CSF Elimination is dose dependent with renal and biliary routes Hepatic metabolism --> dose reduction with liver dysfunction Use with caution in patients with neurologic disease

Answer 240

GI upset neurologic signs associated with higher doses and prolonged use Clinical signs: vertical nystagmus, ataxia, paraparesis, tetraparesis, hypermetria, head tilt, tremors Treatment: discontinue therapy and provide supportive care (IV fluids, antiemetics, sedatives PRN). Most patients improve within 3 days.

Answer 241

Phenicol Bacteriostatic Inhibit protein synthesis by binding to 50S ribosomal subunit In mammalian cells, can also inhibit mitochondrial protein synthesis (especially erythropoietic cells).

Answer 242

Gram-positive Gram-negative anaerobic intracellular organisms such as: Chlamydia, mycoplasma and rickettsia Not effective against pseudomonas aeruginosa

Answer 243

Good bioavailability through oral administration and tissue distribution Penetrates CNS Limited prostate Hepatic metabolism --> dose reduction with liver dysfunction Excreted in kidneys in mostly inactive form

Answer 244

Dose-dependent bone marrow suppression in humans, dogs and cats (cats more sensitive) **DO NOT SPLIT** **DO NOT PULVERIZE** Caretakers to wear gloves Dogs: hind end weakness and GI signs

Answer 245

Chloramphenicol is a potent inhibitor of CYP450. Drugs that require CYP450 may need dose adjust to prevent toxicity.

Answer 246

Competitive inhibitors of 50S ribosomal subunits Do not give chloramphenicols with lincosamides and macrolides Tetracyclines bind to 30S subunit Therefore Chloramphenicols may act synergistically with tetracyclines

Answer 247

Lincosamide Antimicrobial binds to 50S subunit of ribosome Bacteriostatic and time dependent

Answer 248

Effective against gram-positive aerobes and anaerobes Effective against mycoplasma and toxoplasmosis

Answer 249

Good bioavailability after oral administration. Can also be administered SQ and IV Good tissue distribution especially to skin and bone penetrates CNS penetrates blood prostate barrier --> good for gram-positive bacterial prostatitis penetrates biofilms --> use for gingivitis, and peridontal disease

Answer 250

Overall rare Humans: overgrowth of C. diff

Answer 251

Tetracycline inhibits protein synthesis by binding to 30S ribosomal subunit bacteriostatic Lipid soluble --> greater bacterial penetration

Answer 252

1st line therapy for tick borne rickettsial diseases felin upper airway canine respiratory Gram-positive, gram-negative, mycoplasma, chlamydia, rickettsial, spirochetes not considered effective against anaerobic infections

Answer 253

found in all bacteria secondary to presence of efflux pumps alterations to binding sites bacterial enzymatic destruction

Answer 254

high bioavailability drug is lipophilic so will also distribute into placenta and milk limited in prostate highly protein bound 30%-40% CSF elimination: mostly unknown with 16% in urine unchanged predominance for intestinal elimination and enterohepatic recirculation

Answer 255

Adverse effects more likely with decrease in rental function. Give with food to decrease GI upset Associated with ESOPHAGEAL EROSION - follow with 6ml water Incorporates into bone and enamel resulting in discoloration IV Doxycycline needs to be diluted and ideally given through central line to reduce risk of thrombophlebitis Give over 1 hour as anaphylactic shock has been reported Rarely hepatotoxic

Answer 256

should not be administered with antacids, aspirin or calcium containing fluids as it chelates with cations May bind to cholestyramine because of its lipophilic nature

Answer 257

individually - bacteriostatic used together = bactericidal and time dependent work on different stages of bacterial folic acid production Combo therapy 1:5 trimethoprim: sulfonamide

Answer 258

broad spectrum gram-positive, gram-negative and anaerobes Ineffective against mycoplasma and rickettsial disease

Answer 259

goo tissue distribution to include CNS for sulfadiazine and prostate for trimethoprim Both drugs undergo hepatic metabolism metabolites thought to be responsible for allergic and idiosyncratic reactions Both active drug and metabolites renally excreted TMS highly concentrated in urine therefore considered 1st line therapy for bacterial cystitis

Answer 260

allogenic, immunogenic and toxic metabolites (Dobermans, Samoyeds and Mini schnauzers more sensitive) hypersensitivity reactions: fever, polyarthritis, pancreatitis, hepatitis, glomerulonephritis, anemia, ITP, mucosal skin lesions. KCS most common because of direct cytotoxic effects of sulfonamides on lacrimal gland reversible with short treatments (<5 days), but may be irreversible with long term use. decrease in thyroid hormone in dogs --> reversible

Answer 261

drugs: Erythromycin, azithromycin, clarithromycin Mechanism of action: binds to 50S subunit inhibiting protein synthesis Bacteriostatis

Answer 262

Mainly effective against gram-positive bacteria and intracellular bacterial infections limited effectiveness against Gram-negative bacteria Not effective against anaerobic bacteria

Answer 263

Alternative drug option for patients that cannot take beta-lactams (allergies)

Answer 264

Macrolide enteral and parenteral administration rapid degradation by gastric acid when given orally DO NOT CRUSH TABLETS b/c coating helps prevent rapid degradation Drug of choice for Campylobacter jejuni

Answer 265

Macrolide Greater activity against gram-negative organisms More stable in acid --> higher bioavailability when taken orally

Answer 266

GI upset most commonly reported also highly effective as a prokinetic when administered at subantimicrobial doses

Answer 267

Prescription based on culture and susceptibility and lack of any other viable alternative treatment for multi drug resistant UTI inhibits cell wall synthesis, bacterial protein and DNA synthesis bactericidal Gram Positive and gram negative resistance is rare side effects: irreversible peripheral neuropathies use with caution in cats --> potential for hemolysis

Answer 268

Prescription based on culture and susceptibility and lack of any other viable alternative glycopeptide antibiotic Reserved only for serious life-threatening multi-drug resistant gram-positive bacterial infections that cannot be treated with other agents (ie MRSA) Mechanism of action: inhibits proper cell wall synthesis by binding to subunits preventing cross-link formation in peptidoglycan cell wall Adverse effects: nephrotoxicity, ototoxicity Rapid IV administration can be associated with histamine release Extravasation can result in severe soft tissue damage

Answer 269

Prescription based on culture and susceptibility and lack of any other viable alternative used to treat Methicillin-resistant staphylococcal pyodermas Mechanism of action: inhibits RNA synthesis Resistance develops in as short as 2 days when used as monotherapy Use in combo with other drugs to decrease emergence to resistance Rifampin + fluoroquinolone --> antagonistic Fair to good oral bioavailability when fasted Side effects: GI upset and hepatotoxicity Pretreatment and weekly biochem monitoring for hepatotoxicity

Answer 270

Prescription based on culture and susceptibility and lack of any other viable alternative Linezolid - synthetic antibiotic Treatment for multidrug resistant skin infections, pneumonia and bacteremia Mechanism of action: binds to p-site of 50S ribsomal subunit --> inhibit protein synthesis Bacteriostatic effective against gram-positive, including methicillin and vancomycin resistant staphylococci Anaerobic spectrum similar to clindamycin Good bioavailability with tissue distribution to lungs, CSF , bones well tolerated with dogs. No studies on cat pharmacokinetics

Answer 271

Prescription based on culture and susceptibility and lack of any other viable alternative Most recently discovered Drug: Daptomycin indicated for Gram-positive that are vancomycin resistant effective against gram-positive and anaerobic Mechanism of action: forms ion channels in cell membrane allowing it to depolarize and result in rapid cell death Gram-negative organisms inherently resistant Adverse effects: highly toxic, causes skeletal muscle damage

Answer 272

Polyene antibiotics Azole derivatives

Answer 273

1. amphotericin B 2. lipid-complexed emphotericin B

Pharmacology Flashcards

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