Pharm Flashcards
(242 cards)
1
Q
Bethanechol drug class
A
cholinergic
2
Q
bethanechol indications
A
used primary to inc bladder contractility
–acute & partial detrusor atony secondary to acute bladder overdistension and partial neurogenic lesions
3
Q
Bethanechol alternative indications in horses
A
adjunctive prokinetic agent for tx of equine gastric ulcer syndrome (EGUS)
4
Q
Bethanechol altnerative indication in ruminants
A
INC abomasum and duodenum contractility with healthy dairy cattle and those with left displacement of the abomasum (LDA)
5
Q
Bethanechol pharmacology/actions
A
stimulates cholinergic receptors
**effects principally muscarinic negligible nicotinic activity
6
Q
Bethanechol pharmacologic effects
A
- INC esophageal persistalsis and lower esophageal sphincter tone
- INC sphincter tone
- INC tone & peristatic activity of stomach and intestines
- INC gastric and pancreatic secretions
- INC tone of detrusor mm of bladder
- DEC bladder capacity
7
Q
Bethanechol at high doses
A
INC bronchial secretions & constriction
- lacrimation
- salivation
8
Q
Bethanechol contraindications
A
- GI or urinary tract obstructions
- bladder wall integrity is in question
9
Q
Bethanechol adverse effects in horses
A
Salivation
lacrimation
abdominal pain (colic)
10
Q
bethanechol if used IM/IV can cause
A
Severe cholinergic reactions
- salivation, tearing & sweating, bronchoconstriciton, bradycardia, inc GI motility, diarrhea
11
Q
Metoclopramide drug class
A
GI prokinetic agent
12
Q
Metoclopramide indications
A
- Stimulates upper GI motility & has anti-emetic properties
13
Q
Metoclopramide pharmacological effect
A
(not completely known)
Sensitizes upper GI smooth mm effects of acetylcholine
–anti-cholinergic drugs will negate metoclopramides effects
14
Q
Metoclopramide in CNS effects
A
Antagonizes dopamine (D3) at receptor sites
– weak inhibitor of 5-HT3– agonist of 5HT4 receptors
–> sedative, central anti-emetic, extrapyramidal and prolactin secretion stimulation effects
15
Q
Metoclopramide contraindications
A
GI hemorrhage
obstruction or perforation
hypersensitivity
**relatively contraindicated: seizure disorders, pheochromocytoma
16
Q
Metoclopramide adverse effects
A
Severe CNS effects
–>Alternating periods of sedation & excitement, beahvioral changes & abdominal pain
17
Q
Omeprazole drug class
A
Proton pump inhibitor
18
Q
Omeprazole pharmacological actions
A
Benzimidazole gastric acid (proton) pump inhibitor
- –> activated to sulphenamide derivative that binds at secretory surface of parietal cells to the enzyme, H-K ATPase
- inhibits strnasport of H ions into stomach
- reduces acid secretion
19
Q
Omeprazole inhibits what enzyme?
A
Hepatic cytochrome P-450 mixed function oxidase system
20
Q
Omeprazole is metabolized by what organ?
A
IN the liver
21
Q
Sucralfate Drug Class
A
GI mucosal protectant
22
Q
Sucralfate indications
A
Tx of oral, esophageal, gastric & duodenal ulcers
23
Q
Sucralfate MOA
A
**Exact mechanism unknown
- local effect
- reacts with hydrochloric acid in stomach to form paste-like complex that will bind to proteinaceous exudates found at ulcer sites
- insoluble complex forms a barrier at site & protects ulcer from further damage caused by pepsin, acid or bile
24
Q
Misoprostal drug class
A
Prostaglandin E1 Analog
25
Misoprostol indications
Treating or preventing gastric ulcers
Uterine contractibility & cervical softening/opening (pregnancy termination)
26
Misoprostol pharmacology actions
Direct action on parietal cells
* inhibits basal & nocturnal gastric acid secretion
* pepsin secretion decreased
* cytoprotective effect on gastric mucosa--\> INC production of gastric mucus & bicarbonate, INC turnover & blood supply of gastric mucosal cells
Uterine contractions
27
Misoprostol contraindications
Pregnancy & nursing others
Caution: sensitivty to prostaglandins & prostaglandin analogues; pts with cerebral or coronary vascular dz
28
Misoprostol adverse effects
GI distress (diarrhea, adbom pain, vomiting/flatulence)
\*\*pregnant women should handle with caution\*\*
29
Cisapride drug class
Pro-motility agent
30
Cisapride indications
Oral GI prokinetic-- used in several spp for GI stasis, reflux esophagitis & constipation/megacolon (cats)
\*\*no longer commerically available\*\*
31
Cisapride contraindications
Hypersensitivity
GI perforation or obstruction
Hemorrhage
32
Cisapride pharmacology actions
INC lower esophageal peristalsis & sphincter pressure
accelerates gastric emptying
--\> enhances release of acetylcholine at myenteric plexues (does not induce myenetric plexus, but does not induce nicotinic or muscarinic receptor stim)
33
Naloxone drug class
Antidote: opiate antagonist
34
Naloxone pharmacologic actions
\*\* exact mech unknown
* competitive antagonist by binding to the mu, kappa & sigmoid opioid receptor sites
* high affinity for mu receptor
35
Naloxone effect on horses:
low end of dosing range: limit opioid induced locomotor actiivty
Upper end of dosing range: may stimulate colonic propulsion
36
Flunixin meglumine drug class
Non-steroidal anti-inflammatory agent
37
Flunixin meglumine use caution in:
GI ulcers, renal, hepatic or hematologic dzes
--horses with colic-- may mask behavioral & cardiopulmonary signs assoc with endotoxemia or intesitnal devitalization
38
Flunixin meglumine pharmacology/actions:
potent inhibitor of cyclooxygenase
-- analagesic, anti-inflammatory & antipyretic activity
39
Phenylbutazone drug class
Non-steroidal anti-inflammatory agent
40
Phenylbutazone contraindications
known hypersensitivity
history of or pre-existing hematologic or bone marrow abnormalities pre-existing GI ulcers
41
Phenylbutazone pharacologic actions
inhibition of cyclooxygenase-- reducing prostaglandin synthesis
Other effects: reduced renal blood flow, dec GFR, dec plt aggregation, gastric mucosal damage
42
Phenylbutazone adverse effects in horses
oral & GI erosions & ulcers
hypoalbuminemia
diarrhea
anorexia
renal effects
43
Administration of phenylbutazone intrmauscular can cause
irritating: swelling ot necrosis & sloughing
44
Fenbendazole indicated for removal of following parasites in horses:
large strongyles (S. edentatus, S. equinus, S. vulgaris)
Small strongyles (Cyathostomum spp., Cyclicocylus spp., Cyclicostephanus spp., Triodontroophorus spp.)
Pin worms (oxyuris equi)
45
Fenbendazole indicating for following parasites in cattle:
Haemonchus contortus, Ostertagia ostertagi, Trichostorngylus axei, Brunostomum phelbotomum, Nematodirus helvetianus, Cooperia spp., Trichostrongylus colubriformis, Oesophagostomum radiatum, Dictyocaulus viviparus
46
Acetylcystein indications
mucolytic
treatment for acetaminophen tox or other hepatotoxic conditions were glutathione syntehsis is inhibited or oxidative stress occurs
47
Acetylcysteine used in horses for what indication
Strangles-- acetylcysteine instilled into guttural pouch used ot help break up chondroids & avoid the need for surgical removal
Meconium impaciton-- foals: break up meconium refractory to repeated enemas
48
Acetylcystein MOA as a mucolytic
Reduces viscosity of purulent & nonpurulent secretions & expedites removal of secretions via coughing, suction or postural drainage
* free sulfhydryl group on drug reduces disulfide linkages in mucoproteins
* pronounced action at pH from 7-9
49
Acetylcysteine actions on liver d/t acetominophen toxicity
* reduce extent of liver injury or methemoglobemia after ingestion of acetaminophen or phenol
* provides an alterante substrate for conjugations with reactive metabolite of acetaminophen-- maintaining or restoring glutathione level s
50
Acetylcysteine advers effect when administered into pulmonary tract
hypersensitivity
chest tightness
bronchoconstriction
bronchial or tracheal irritation
51
S-Adenosyl-methionine drug class
Hepatoprotectant
52
S-Adenosyl-methionine Pharacological action
Endogenous molecuels synthesized by cells throughout the body
* formed from amino acid methionine
* SAMe-- essenital part of 3 major biochemical pathways
* beneficial effects: inc liver & rbc glutahtione levels &/or prevent its depletion; inhibts apoptosis secondary to acohol or bile acids in hepatocytes
53
Pentoxifylline pharmacological actions
* INC RBC flexibility by inhibiting rbc phosphodiesterase & dec rbc viscosity by dec plasma fibrinogen
* INC fibrinolytic activity
* horses-- potent inihibitor of matrix metalloproteinase-9 & 2
* dec negative endotoxic effects of cytokine medators via phosphodiesterase inhibition
54
Pentoxifylline contraindications:
retinal or cerebral hemorrhage
intolerance or hypersensitivity to xanthines
Caution: severe hepatic or enal impairment or at risk for hemorrhage
55
Pentoxifylline adverse effects
GI tract (vomiting/inappetance) most common
56
Isoflupredone acetate uses/indications
potent glucocorticoid-- anti-inflammatory or immunosuppressive effects:
* labelled indications: adjucntive in bovine ketosis, alleviating pain & lameness assoc with msc conditions, acute hypersenstiivity rxns, adjunctive tx of overwhelming infections with sevre tox, shock, supportive therapy in stress, dystocia, retained palcement, inflamm., ocular conditions, sneakbite & parturient paresis
57
Isoflupredone acetate pharmacological actions
17x more potent anti-inflammatory than hydrocotisone (cortisol)
10x more potent than prednisolone
58
Isoflupredone acetate adverse effects
Hyperadrenocroticism
dairy cattle--hypokalemia
potential adverse effects: dec milk production, delayed wound healing, GI ulceration, INC infection rates, diabetes mellitus exacerbation/hyperglycemia, pancreatitis, hepatopathy, renal dysfunction, osteoporosis, laminitis, hypothyroidism, hyperlipidemia
59
Dexamethasone drug class
Glucocorticoid
60
Glucocorticoids: 3 braod uses/indications
1. Replacement of glucocorticoid activity in patients with adrenal insuffiency
2. anti-inflammatory agent
3. immunosuppressive
61
Glucocorticoids effects on cardiovascular system
* Dec capillary permeability
* enhance vasoconstriction
* POS ionotropic (mild) (inc BP)
62
Glucocorticoids effects on cells
* inhibit fibroblast proliferation
* macro response to migration inhibiting factor
* sensitization of lymphocytes and cellular response to mediators of inflammation
* stabilize lysosomal membranes
63
Glucocorticoids effect on CNS/autonomic nervous sytem
* Lower seizure threshold
* alter mood and behavior
* diminish response to pyrogens
* stim appetite
* maintain alpha rhythm
* glucocorticoids necessary for normal adrenergic receptor sensitivity
64
Glucocorticoids effect on endocrine system
* suppress release of ACTH from anterior pituitary--\> dec release of endogenous corticosteroids
* inihibit osteoblast function
* reduced ADH (vasopressin) activity at renal tubules & diuresis may occur
* inhibits insulin binding to insulin receptors & post-recept effects of insulin
* reduced: TSH, FSH, prolactin & LH at pharmacological doses
65
Glucocorticoids effect on hematopoietic system
* INC number of circulating neuts & rbcs
* plt aggregation inhibited
* dec amts of lymphocytes (peripheral), monos & eos
* removal of old red cells diminished
* can cause involution of lymphoid tissue
66
Glucocorticoids effects on immune system
* dec circulating levels of T lymphs
* inhibit lymphokines
* inhibit neuts, macro & mono migration
* reduce production of interferon
* inhibit phagocytosis & chemotaxis
* ag processing
* diminish intracellular killing
* antagonize complement cascade & mask clinical signs of infection
* mast cells decreased in number & histamine suppressed
67
Glucocorticoid effects on metabolism
* stimulate gluconeogenesis
* lipogenesis enhance in certain areas of body
* adipose tissue can be redistrubted away from extremities to trunk
* fatty acids are mobilized from tissues & their oxidation increased
* plasma triglycerides, cholesterol & glycerol increased
* protein mobilize from most areas of body
68
Glucocorticoid effects on musculoskeletal sys
* may cause muscular weakness, atrophy, osteoporosis
* bone growht inhibited via growth hormoen & somatomedin inihibition
* increased Ca excretion
* inhibition of Vit D activation
* resorption of bone can be enhanced
* fibrocartilage growth inhibited
69
Ophthalmic effects of Glucocorticoids
prolonged use (systemic/topical)--\> INC intraocular pressure & glaucoma, cataracts & exopathalmus
70
Glucocorticoid effects on renal, fluid & electrolytes
* INC potassium & Ca excretion
* Na & Cl reabsorption
* extracellular fluid volume
* rare: hypokalemia/hypocalcemia
* diuresis
71
Glucocorticoid effects on skin
* thinning of dermal tissue & skin atrophy
* hair follicles can become distended & alopecia may occur
72
Propylene glycol base injectable production administration rapidly can cause
Hypotension
Collapse
Hemolytic Anemia
\*\*most drug formualtions use sodiu mphosphate when givin drug intravenously\*\*
73
Triamcinolone Acetonide intraarticular injeciton in horses shown to cause
* improvement clinical lamenss
* reduce articular protein, inflammatory cell infiltraiton, animal hyperplasia & subintimal fibrosis
* synovial levels of hyaluronan & glycosaminoglycan can be increased
74
Ivermectin is approved for control of what parasites in horses
* **Large adult strongyles**: strongylus vulgaris, S. Edentatus, S. Equinus Triodontophorus spp
* **Small strongyles**
* **pinworms** (adults & 4th stage larva)
* **ascarids** (adults)
* hair worms (adults)
* large mouth stomach worms (adults)
* beck threadworms (microfilaria)
* bots (oral & gastric stages)
* **lungworms** (adults & 4th stage larva0
* intestinal threadworms (adults)
* summer sores (cutaneous 3rd stage larva) econdary to Hebronema or Draschia spp.
75
Ivermectin is labeled for control of what parasites in cattle
* roundworms (adults & 4th stage larva)
* lungworms (adults & 4th stage larva)
* cattle grubs (parasitic stages)
* sucking lice
* mites (scabies)
76
Ivermectin pharmacological actions
* enhances release of GABA at pre-synpatic neurons
* blocks postsynaptic stim of adjacent neuron in nematodes or mm fiber in athropods
* causes **paralysis** of parasite & eventual death
77
Ivermectin is ineffective against liver flukes & tapeworms because
Do not use GABA as pierpheral nerve transmitter
78
Amphotericin B pharmacologic actions
acts by binding sterols (primarily ergosterol) in cell membrane & alters permeability of membrane allowing intraclelular K & other cellular constituents to leak out
79
Amphotericin B is ineffective against rickettsia & bacteria because
has no activity against these organisms
80
Amphotericin B in vitro activity against what fungal organisms
* blastomyces
* aspergillus
* paracoccidioides
* coccidioides
* histoplasma
* cryptococcus
* mucor
* sporothrix
81
Amphotericin adverse effects in hroses
tachycardia
tachypnea
lethargy
fever
restlessness
fever
anorexia
anemia
phlebitis
polyuria
collapse
82
Amphotericin B nephrotoxicity
renal vasoconstriction wiht subsequent reduction in GFR
\*\*monitor renal values aggressively during therapy\*\*
83
Acyclovir tx in horses
investigated in EHV-5, lymphoma, EHV-1 myelonencephalopathy
\*\*poor bioavailability is an issue
84
Acyclovir adverse effects
thrombophlebitis
acute renal failure
encephelopathologic changes (rare)
GI disturbances-- oral or parenteral therapy
85
Class 1 Antiarrythmic agents
Na channel blockers
-- block voltage gated sodium channels of myocardium
86
Class 1a antiarrhythmic agetns
block fast sodium channels
-- prolong action potential activity-- lengthening the effective refractory period
potentially proarrythmic-- QT interval prolongation (promoting reentry)
Tx of supraventricular & ventricular tachyarrythmias
87
Class 1a antiarrhythmic agents examples
Quinidine
procainamide
88
Quinidine indications
atrial fibrillation
(quinidine gluconate): ventricular tachycardia (VT-) discontinued in 2017
89
Quinidine pharmacological actions
slow impulse conduction
prolong effective reractor period
vagolytic activity--accelerated AV nodal conudction
alpha adrenoreceptor antagonist effects: hypotension & reflex INC in sympathetic outflow (poteniates proarrhythmic effects)
90
Quinidine adverse effects in horses
* inappetance
* depression
* swelling of nasal mucosa
* ataxia
* diarrhea
* colic
* hypotension
* rarely: laminitis, paraphimosis & development of urticarial wheels; cardiac arrthmias: AV block, circulatory collapse & sudden death
91
Procainamide indications
acute management of VT (& VPCs)
acute onset AF in horses
92
Procainamide action
* Prolongs refractory times in both atria & ventricles
* decreases myocardial excitability
* depresses automaticity and conduction velocity
* some anticholinergic effects
93
Procainamide contraindicated
* myasthenia gravis
* hyerpsensitivity to drug, procaine or other chemically related drugs
* torsade de pointes
* 2nd or 3rd degree heart block (unless artificially paced)
* EXTREME CAUTION: cardiac glycoside intoxication, systemic lupus
* CAUTION: signficant hepatic, renal dz or CHF
94
Procainamide adverse effects
* Reported in the dog: GIT effects: anorexia, vomiting & diarrhea
* CV: weakness, hypotension, neg inotropism, widened WRS complex & QT intervals, AV block, multiform ventricular tachycardia
* profound hypotension if injected too rapidly
95
Class 1b anti-arrhythmic agents used for management of
Ventricular arrhythmias
* shorten action paotenial without causing QT prolongation
* preferentially bind to Na channels-- act primarily on damaged mycoardial cells ot prevent reentry pathways
96
Class 1b anti-arrhythmic agents examples
lidocaine
phenytoin (diphenylhydantoin)
tocaindide
mexiletine
97
Lidocaine indications
ventricular tachycardia
\*\*less effective in hypokalemia
PIVA--partial intravenous anesthesia-- analgesic, antiiinflammatory & prokinetic effects
--\> prevention of post-op ileus and reperfusion injury & adjunctive tx of endotoxemia
98
Lidocaine pharmacologic actions
* phase 4 diastolic depolarization attenutation
* decreased automaticity
* decrease or no change in membrane responsiveness and excitability
--\>lidocaine acts by combining with fast sodium channels when inactive which inhibits recovery after repolarization
99
phenytoin indications
acute tx of cardiac glycoside induced arrthymias
\*\*rarely used in USA
100
Class 1c antiarrythmic agents MOA
potent inhibitors of fast sodium channels with differential blocked within the Purkinje fibers with little impact on surrounding myocardium
101
Class 1c antiarrythmic drugs should not be used in
pateitns with documented structural heart disease or myocardial damage
102
Examples of Class 1c antiarrhythmic drugs
flecainide
propafenone
103
Flecainide indications
researched in the management of afib & vtch-- cannot be recommended in hrose b/c narrow safety profile
104
Propafenone indication
treatment of sustained supraventricular tachycardia, VT, Ventricular premature complexes in humans
\*\*under investigation in veterinary spp\*\*
105
Class II antiarrhythmic agents MOA
Beta-adrenoceptor antagonists (beta blockers)
* prolong phase 4 of cardiac action potential-- suppressing SA pacemaker activity & AV nodal conduction--\> slowing heart rate
* negative inotropic & anti-arrythmic effects
106
3 subtypes of beta-adrenoreceptors in teh heart
1. beta1: affects force & rate of cardiac contraction, automaticity of the pacemaker sites & conduction through AV node
2. Beta2: located in SA & AV nodes--activations leads to increased automaticity & AV nodal conduction--\> INC rate
3. Beta3: human & canine myocardium-- not identified in equine myocardium
107
Examples of class II anti-arrythmic agents
propanolol
sotalol
atenolol
esmolol
108
Propanolol MOA
* non-specific beta adrenoreceptor antagonists acting on both Beta1 and Beta2 adrenoreceptors
* dose depednet suppression of myocardial contractility
* CV effects: dec heart rate, depressed AV conduction, diminished CO, dec mycoardial O2 demand, dec hepatic & renal blood flow, dec blood pressure, inhibition of isoproterenol induced tachycardia
109
Propanolol indications
supraventricular & ventricular (refractory to other therapies) tachycardias
110
Propanolol contraindications
* heart failure
* hypersensitivity to this class of agents
* greater than 1st degree heart block
* sinus bradycardia
* CHF
* CAUTION: significant renal or hepatic insufficiency, sinus node dysfunction, labile diabetic patients, digitalized or digitalis intoxication
111
Propanolol adverse effects
* bradycardia
* lethargy
* depression
* impaired AV conduction
* CHF or worsening heart failure
* hypotension
* syncope
* diarrhea
* hypoglycemia
* bronchoconstriction
112
Class III anti-arrythmic agents MOA
K channel blockers-- suppress inward potassium current-- prolonging phase 3 of action potential & refractory period
113
Class III antiarrhythmic examples
amiodarone
114
Amiodarone indications
treatment of AF in hroses (lots of adverse effects) and VT resistant to other meds
115
Amiodarone adverse effects
GI
nuerologic
cardiac
derm signs
116
Class IV anti-arrhythmic agents function
Calcium channel blockers-- act on phase 2 of cardiac potential
* primarily act on nodal tissues
117
Class IV anti-arrythmic indications
supraventricular arrythmias in humans & dogs, have not be eval in horses
118
Diltiazem indication in horses
in combination with quinidine to tx atrial fibrillation in horses
119
Magnesium sulfate indications
* terminating refractory ventricular arrhythmias
* --\> reduce occurrence of ventricular atopy and VT in human patients with CHF
* tx of choice for quinidine induced torsades de pointeses
120
Magnesium sulfate can potentiate the effects of:
lidocaine: through its effects on na/K atpase transporters in patients with hypokalemia
121
Anticholinergic agents effective in controlling (cardiovascular)
Vagal mediated bradyarrhythmias
--\> competitively inhibit binding of acetylcholine to the postganglionic synapses in teh heart-- blocking vagally induced slowing of heart rate predom used to tx or prevent life-trheatning drug-induced bradycardia
122
Class II anti-arrhythmic indication
tx of supraventricular arrythmias in humans & dogs-- not critically evaluated in horses
123
124
Atropine indications
* tx sinus bradycardia, sinoatrial arrest, incomplete AV block
* differentiate vagally-mediated bradycardia for other causes
* antidote for overdoses of cholinergic agents (eg, physostigmine, etc.)
* antidote for organophosphate, carbamate, muscarinic mushroom, blue-green algae intoxciation
* hypersialism: reduce secretions
* tx (adjunctive) of bronchosontrictive dz
125
Atropine pharmacological actions
Antimuscarinic agents-- competitively inhibits acetylcholine or other cholinergic stimualtes at postganglionic parasympathetic neuroeffector sites
dose related effects:
* low: salivation, bronchial secretions & sweating (no horses) are inhibited
* moderate: atoprine dilates & inhibits accomodation of pupil, INC heart rate
* high: dec GI & urinary tract motility, inhibit gastric secretion
126
Atropine contraindicated:
* Narrow-eyed glaucoma
* synechia (adhesions) between iris & lens
* hyeprsensitivity to anticholinergic drugs
* tachycardias secondary to thyrotoxicosis or cardiac insufficiency
* myocardial ischemia
* unstable cardiac status during acute hemorrhage
* GI obstructive dz
* paralytic ileus
* severe ulcerative colitis
* obstructive uropathy
* myastehnia gravis (unless used to reverse adverse muscarinic effects secondary to therapy
Extreme caution: autonomic neuropathy
127
Atropine GI effects
* Dry mouth (xerostomia)
* increased viscosity of secretions
* dysphagia
* constipation
* vomiting
* thirst
* urinary retention
128
Atropine CNS effects
* stimulation
* drowsiness
* ataxia
* seizures
* respiratory depression
129
Atropine ophthalmic effects
* Blurred vision
* pupil dilation
* cycloplegia
* photophobia
130
Atropine cardiovascular effects
* Sinus tachycardia (at higher doses)
* increased myocardial work & O2 consumption
* bradycardia (initially or at very low doses)
* hypertension
* arrhythmias (ectopic complexes)
* circulatory failure
131
Physostigmine drug class
cholinesterase inhibitor (reversal for atropine)
132
physostigmine indications
* detect ivermectin tox in dogs
* provacative gent for dx of narcolepsy in dogs & horses
* tx of anticholinergic tox
133
Phystostigmine pharmacological actions
* reversibility inhibits destruction of acetylcholine by acetylcholinesterase-- increasing acetylcholine at receptor sites
* cross BBB and inhibits acetylcholiensterase both centrally and peripherally
* miosis, bronchial constriction, hypersalivation, mm wekaness, sweating
134
Physostigmine at higher dosages can cause
cholinergic crisis: seizures, bradycardia/tachycardia, asystole, nausea, vomiting, diarrhea, depolarizing neuromuscular block, pulmonary edema & respiratory paralysis
135
Glycopyrrolate drug class
anticholinergic
136
Glycopyrrolate indications
* Sinus bradycardia (use in life-threatening cases d/t GI side effects)
* sinoatrial arrest
* incomplete AV blockade
137
Glycopyrrolate is similar to atropine, except for what effects seen with atropine, not seen with glycopyrrolate
does not cross appreciably into the CNS
\*\*CNS effects are not exhibited to the same effect as atropine
138
N-butylscopolamine bromide drug class
quaternary ammonium antispasmodic and anticholinergic
139
N-butylscopolamine bromide indications
* control of abdominal pain assoc with spasmodic colic, flatulent colic & simple impactions in horses
* esophageal obstruction
* bradycardia
* acute RAO
\*\*shorter acting than atropine
140
N-butylscopolamine bromide pharmacological actions
Dec peristalsis & rectal pressure via:
* anti-cholinergic actions by competitively inhibiting muscarinic receptors on smooth mm
* bronchodilatory and chronotropic effects in horses
141
Mannitol drug class
osmotic diuertic
142
Mannitol indications
* diuresis in acute oliguric renal failure
* reduce intraocular and intracerebral pressures
* enhance urinary excretion of some toxins (eg, aspirin, some barbiturates, bromides, ethylene glycol)
* conjunction with other diuretics to reduce edema or ascites
143
Mannitol pharmacological actions
* free filtered at glomerulus and poorly reabsorbed in the tubule
* increased osmotic pressure prevents water from being reabsorbed at the tubule
144
For mannitol to be effective what must be intact
sufficient renal blood flow and filtraiton for mannitol to reach the tubules
145
Increased excretion of Mannitol promotes excretion of what other substances
sodium, other electrolytes, uric acid & urea
146
Mannitol contraindications
Anuria secondary to renal disease
Severe dehydration
Severe pulmonary congestion or pulmonary edema
147
148
Mannitol adverse effects
* Fluid and electrolyte imbalances
* GI (nausea, vomiting)
* cardiovascular (pulmonary edema, CHF, tachycardia)
* CNS effects (dizziness, headache, etc.)
149
Furosemide drug class
loop diuretic
150
Furosemide indication
Congestive cardiomyopathy
pulmonary edema
udder edema
hypercalcuric nephropathy
uremia
hyperkalemia (adjunctive therapy)
EIPH- racehorses
151
Furosemide pharmacological actions
Transient increases in GFR
* aLOH: reduces absorption of electrolytes (dec reabsorption of both sodium and chloride)
* distal renal tubule: increases excretion of potassium
* proximal tubule: directly effects electrolyte transport
152
Furosemide contraindicated in:
* anuria
* hypersensitivity
* seriously depleted electrolytes
* CAUTION: patients with pre-existing electrolyte or water balance abnormalities, paired hepatic function & diabetes mellitus
153
Thiazide diuretics MOA
inhibit the sodium/chloride symporter in renal epithelial cell of the distal convoluted tubule
* increases loss of sodium, chloride & water
154
Drugs to reduce preload on the heart
Loop diuretics: furosemide
Thiazide diuretics: amioloride
155
Drugs to reduce afterload on the heart
inhibitors of RAAS
ACE inhibitors (spirinoloactone)
direct acting vasodilators (hydralazine, nitrates/nitroglycerine, acepromazine)
156
ACE inhibitors indications
Effective in managing CHF & delaying progression of both symptomatic & asymptomatic heart disease
* hypertension
* heart failure
* chronic renal failure
* protein losing glomerulonephropathies in dogs & cats
157
Benazepril pharmacological actions
* after metabolism to benazeprilate-- drug inhibits of angiotensin I to angiotensin II by inhibiting angiotensin convertin enzyme (ACE)
* angiotensin II acts as a vasoconstrcitors & stim production of aldosterone in adrenal cortex
* by blocking angiotensin II formation-- generally dec blood pressure in hypertesnive patients & vascular resistance in patietns with CHF
158
Benazepril contraindicated in:
acute kidney injury
CAUTION: patients with INC Crea, hyponatremia, coronary or cerebrovascular insufficiency, SLE, hematologic disorders
159
Acepromazine causes vasodilation in horses via
alpha adrenoreceptor and 5 hydroxtryptamine (serotonin)receptor antagonist
160
Antibiotics that are bactericidal
* Penicillins (PPG, Kpenn)
* cephalosporins (Naxcel/Excede)
* Aminoglycosides (Gent, Amikacin)
* Fluoroquinolones (Enrofloxacin)
* Metronidazole
* Rifampin
161
Antibiotics that are bacteirostatic
potentiated sulfonamides (TMS)
Tetracyclines (Oxytet, Doxy, Mino)
Chloramphenicol
Macrolides
162
Bacteriostatic vs bacteriocidal
bactericidal-- kills bacteria
bacteriostatic-- inhibits bact growth
163
Time dependent antibiotics MOA
time spent above MIC for duration of dosing interval
164
Examples of time dependent antibitoics
Pencillins (PPG, Kpenn)
Cephalosporins (Naxcel, Excede)
Potentiated sulfonamides (TMS)
Tetracyclines (oxy, doxy, mino)
Chloramphenicol
Macrolides (erythromycin, azithromycin, chlarithromycin)
165
Concentraiton dependent antibitoics mechanism of action
maximize plasma concentration
166
Concentration depdent antibiotics examples
Aminoglycosides (gent, Amikacin)
Fluoroquinolones (Enrofloxacin)
167
MOA: Beta-lactams
inhibit cell wall synthesis--\> by acting on penicillin binding proteins (PBPs) responsible for building the cell wall
168
MOA: Aminoglycosides
inhibit protein (30 s ribosomal subunit) synthesis
\*\*synergism with beta-lactams\*\*
169
MOA: Tetracyclines
Binds to 30s ribosomal subunit to interfere with bact protein synthesis
170
MOA: flouroquinolones
inhibit bacterial DNA gyrase (topoisomeraseII)
171
MOA: potentiated sulfonamides
sulfonamide: inhibit bact dihydropoteroate synthetase (DPS)in folic acid pathway
Trimethoprim: inhibits dihydrofolate reductase in next step of folic acid pathway (inihibiting bact nucleic acid synthesis)
172
MOA: rifampin
inhibits DNA-dependent RNA polymerase to suppress RNA synthesis
173
MOA: Macrolides
bind 50-s ribosomal subunit to inhibit protein synthesis
174
MOA: phenicols
Inhibit protein synthesis by binding 50-s ribosomal subunit
175
MOA: metronidazole
inhibit protein synthesis by binding 50-s ribosomal subunit
176
Antibiotics spectrum of activity: gram positive
Penicillins
macrolides (some pasteurella & histopholus)
cephalosporins
rifampin
177
Antibiotics spectrum of activity: gram negative
Aminoglycosides
Fluoroquinolones (intracellular organisms)
178
Antibiotics gram positive & negative coverage
Tetracyclines (intracellular organisms)
chloramphenicol
Cephalosporins (some negative)
Rifampin (some neg)
179
Antibiotics with anaerobic bacterial coverage
Penicillin- except beta-lactams producing Bacteroides spp
Cephalosporin-- excluding Bacteroides
Chloramphenicol
Metronidazole
180
Using MIC to direct antibiotic therapy
=: can use this antibiotic against the cultured bacteria
181
Antibiotics eliminated by the kidney
penicillins
cephalosporins
amingglycosides
TMS
Tetracyclines
Fluoroquinolones
Chloramphenicol
Metronidazole
Rifampin
182
Antibiotics eliminated by the liver
Tetracyclines (enterohepatic circulation)
TMS
Fluoroquinolones (first pass heaptic metabolism)
Chloramphenicol
Metronidazole
Rifampin
Macrolides (w/ bile excretion)
183
Adverse effects of penicillins
IMHA: type 2 hypersensitivity-- resolves with d/c therapy
anaphylaxis: T. 1 hypersensitivity-- d/t previous exposure to penicillin
184
CNS excitement in procaine reactions
procaine hydrolyzed by plasma esterases to nontoxic metabolites PABA & diethlaminoethanol
185
Aminoglycoside nephrotoxicity mech
enter renal tubule after filtration from glomerulus
* bind anionic phospholipids on PCT cells
* taken into cell by carrier medaited pinocytosis & translocated into cytoplasmic vacuoles which fuse with lysosomes
* overloaded lysosomes swell and rupture-- disrupte PCT cells and cause cell death
186
Disease processes do not want to use the aminoglycosides
dzes that cause neuromuscular blocake (ie. Botulism)
--because can block acetylcholine at nicotinic cholinergic receptors & can precipitate neuromuscular blockade
187
Chloramphenicol can decreased clearance of medications through which process
chloramphenicol is metabolized by same cytochome P450 enzymes
Other drugs: phenytoin, phenobarb, phenylbutazone, xylazine, cyclophosphamide
188
Chloramphenicol use is not recommended with fllouroquinolones because of what metabolism
inhibition of protein synthesis by interfering with production fo autolysins necessary for cell lysis after fluoroquinolones interfere with DNA supercoiling
189
Bacteria that are resistant to TMS and through which mechanism
* Pseudomonas spp., Bacteroides spp., enterococci
* mediated by chromosomal mutations--\> bact hyperproduction of PABA, overcomes competitive substitution of sulfonamides or mediated by plasmids --\> bypass of drug sensitivity step by production of later forms of DPS enzyme with lower affinity of sulfonamides
190
Bacteria that overproduce what enzyme, will make it impenetrable to TMS
excessive bact production of dihydrofolate reductase (DHFR) and reduction in ability of drug to penetrate bact cell wall
191
TMS what can cause what form of anemia
folate antagonism anemia (folate def /t inhibition of folate prdouction by GIT and inhibition of its ocnversion to tetrahydrofolate & dihydrofolate)
192
Tetracyclines can cause cardiovascular collapse through which mechanism
IV chelation of calcium, DEC bp or BOTH
--\> tachycardia, arrhythmias, systemic arterial hypertension, collapse & deaht d/t chelation of intracellular Ca
193
Tetracycline mediated flexor tendon relaxation
inhibition of collagen gel contraction by equine myofibroblasts-- inhibition of noraml collagen organization
194
Fluoroquinolones negative CNS side effect
GABA antagonism
195
Macrolides can cause CNS excitement, particuarly in foals at what dose
cumulative 60 mg/kg
196
Major food animal species
Cattle
pigs
chickens
turkeys
197
Drugs with no allowable extralabel uses in any food producing animal species
chloramphenicol
clenbuterol
diehtlstilbestereol (DES)
fluoroquinolone-class antibiotics
glycopeptides-- all agents, including vancomycin
medicated feeds
nitroimidazoles-- all agents including dimethridazole, iproindazole, metronidazole
nitrofurans-- all agents, indlucign furazolindine, nitrofurazone & others
198
Adamantane and nueraminidase inhibitors extra label drug are prohibited in:
chickens
turkeys
ducks in USA
\*\*used in other countries for prevention of avian influenza\*\*
199
Cephalosporin ELDU is
restricted in the USA
200
Cephalosporin difference in major & minor species
Major species: only fo rtherapeutic indicaitons & is prohibited in all of the following situations: no deviation form dose, duration frequency of admin route, outside of intended use of product in an unapproved major spp., cannot be sued for purpose of dz prevention
Minor species: ELDU permitted in these species
201
Genitian violet use in Food animals is:
Prohibited
202
Phenylbutazone use in Food animals is:
strictle prohibited in female diary cattle greater than 20 months of age
203
Sulfonamide class antibiotic use in food animals
prohibited in lactating dairy cattle, except for aprpoved uses of sulfadimethoxine, sulfabromotheazine, sulfaethoxypyridazine
204
Oxytetracycline is labeled for:
Beef and dairy cattle for treatment of:
* pneumonia & shipping fever complex assoc with pasteruella & haemophilus
* infectious bovine keratoconjunctivitis (pink eye) caused by morazella bovis
205
Excede (cefiotfur crystalline free acid) label in food animal
Tx of:
* bovine respiratory disease (BRD)
* foot rot
* control of resp dz in cattle at high risk for BRD
206
Excenel (ceftiofur hydrochloride) label in food animal
Treatment of:
* bovine resp disease (BRD, shipping fever, pneumonia)
* foot rot
* acute metritis in cattle
* swine bacterial resp disease (SRD) in swine
207
Enrofloxacin label in food animal
Beef and non-lactating dairy cattle
* BRD- mannheimia haemolytica, pasterella multocida, histophilus somni & mycoplasma bovis
Swine:
* SRD- actinobacillus pleuropneumoniae, pasterella multocida, haemophilus parasuis, strep suis
208
Nuflor (florfenicol) label in food animal
Cattle
* BRD
* foot rot
209
Draxxin (tulatrhomycin) label for use in food animals
* BRD/SRD
* infectious bovine keratoconjunctivitis (IBK)
* foot rot
210
Clenbuterol use in food animals
* illegal/prohibited d/t tissue residue
211
Chlorotetracycline use in food animals
can only use label for Anaplasma
212
If giving concurrent with theophylline, what drug concentration needs to be decreased?
* Enrofloxacin: bronchodilator-- tx asthma & other lung problems
--flouroquinolones inhibit CYPIA2 mtabolism of theophylline
\*\*in dogs INC theophyline concentrations
213
Erythromycin is usually bacteriostatic except for
At high concentrations
\*\* bactericidal (time-dependent) activity\*\*
214
Prokinetic effects of erythromycin are seen at sub-antimicorbial doses due to its action:
effects of motilin or 5-hydroxytryptophan3 (5-HT3)
can stimulate migraitng motility complexes
& antegrade peristalsis
215
Adverse effects of erythromycin
avoid if preexisting liver dysfunction
enterocolitis (adult horses)
hyperthermia (foals)
216
At what age should erythromycin be used cautiously in foals?
\>4 months old
217
Low concentrations of heparin MOA
comb with ATIII inactivate factor Xa and prevent conversion of prothrombin to thrombin
218
Higher concentrations of heparin:
inactivates thormbin
blocks conversion of fibrinogen ot fibrin
when combinated with antirhombin III inactivates factors IX, X, X1, XII
219
By inhibiting factor XIII heparin prevents what:
formation of stable fibrin clost
\*\*does not lyse clots but prevents growth of existing clots
220
heparin causes increases release of what protein?
lipoprotein lipase-- increasing clerance of circulating lipids & boosting plasma levels of free fatty acids
221
When should heparin not be administered?
thrombocytopenia
uncontrollable bleeding (other than DIC)
222
What is the most common adverse effects of heparin in horses?
anemia
\*\*likley d/t erythroycte agglutination
other AE: hemorrahge, thrombocytopenia & pain at injection sites
223
Clopidogrel uses/indications
platelet aggregation inhibitor
224
Clopidogrel MOA
metabolized to active highly unstable thiol compound that is responible for its inhibitory plt aggregation activity (primary and seconadry aggregation)
binds selectively to plt surface low affinity ADP receptors & inhibits ADP binding to the site therapy reducingplt aggregation
225
How long is the mechanism of clopidogrel?
Clopidogrels active metabolite irreverisbyl alters the ADP receotr
\*\*platelet is altered for its lifespan
226
How is the mechanism of Clopidogrel different from Aspirin?
Aspirin acetylates and ianctivates COX-1 on plts, thereby preventing formation of thromboxane A2
227
Is clopridogrel safe to be used with heparin?
yes
\*\*both unfractionated and LMW
228
Aspirin mechanism of action
inhibits cyclooxygenase (COX-1, prostaglandin synthetase), reducing the syntehsisi of prostalgandins & thormboxanes (TXA2)
229
Aspirin administration is contraindicated in:
bleeding ulcers
hemorrahgic disorders
asthma
renal insufficiency
hypoalbuminemia (lower dosages to prevent C/S of tox)
230
Most common adverse effect of aspirin administration
gastric (nausea, anorexia, vomiting) or intestinal irritation
231
Neostigmine is what kind of drug?
parasympathomimetic (cholinergic)
232
What is neostigmine labeled for?
rumen atony
initiating peristalysis
emptying the bladder
sitmulating skeletal mm contractions
233
neostigmine MOA
compets with actylcholine for actylhcolinesterase-- hydrolyzed at a sloweer rate than acetylcholine-enzyme complex
\*\*acetylcholine willa ccumulate with a restulant exaggeration & prolongation of effects--\> INC ton e of itnesinal & skeletal mm, stim of salivary & sweat glands, rbonchoocnstriction, urter constriciton, miosis & bradycardia
234
Neostigmine is contraindicated in patients with:
peritonitis
mechanical intestinal or urinary tract obstructions
late stages of pregnancy
235
Adverse effects of neostigmine
cholinergic in nature & dose related
(nause, vomiting, diarrhea, excessive salivation& drooling, sewating, miosis, lacrimation, inc bronchial secretions, bradycardia or tachycardia, cardiospasm, bronchospasm, hypotension, mm cramps & weakness, agitation,r estlessness or parlaysis)
236
Dantrolene sodium indication
skeletal mm relaxation
\*\*horses: post anesthesia myositis/acute rhabdomyolysis
\*\*malignant hyperthermia
237
Dantrolene sodium MOA
\*\*exact mech not well understood
acts on skeelta mm by interfering wiht release of calcium from sarcoplasmic reticulum
238
Dantrolene sodiuma adverse effects
weakness
sedation
increased urinary frequency
GI effects
hepatotoxicity (esp with chronic use)
239
Methocarbamol primary indication?
muscle relaxant
IV in horses: adjunctive therapy of acute inflammatory & traumatic aconditions of skeletal mm to reduce mm spasms & effect stirated mm relaxation
240
Methocarbamol MOA
\*\*Exact MOA unknown
\*\*has no direct relaxant effects on striated mm, nerve fibers or motor endplate (not direclty relax contracted skeletal mm)
241
What is a minor metabolite of the methocarbamol?
quaifenesin
\*\* may have racing regulatory ramifications & little clinical effect
242
Methocarbamol adverse effects
* sedation
* salivation
* emesis
* lethargy
* weakness
* ataxia
* sedation-- horses
