Top 100 Drugs Flashcards

Question

Methotrexate - Interactions

Answer 1

Toxicity likely with drugs that can inhibit its renal excretion - NSAIDs, penicillins Co-prescription with other folate antagonists (Trimethoprim and phenytoin) can lead to haematological abnormalities

Answer 2

Used to treat allergic or inflammatory disorders Suppression of autoimmune disease Cancer treatment as part of chemotherapy or to reduce tumour associated swelling Hormone replacement in adrenal insufficiency or hypoparathyroidism Mechanism of Action Bind to the glucocorticoid receptor - inhibiting pro-inflammatory signals (cytokines and TNF-alpha) and promoting anti-inflammatory signals Decreased vasodilation and permeability of capillaries Suppression of circulating monocytes and eosinophils Gluconeogenesis from increased circulating fatty acids and amino released by fat and muscle catabolism Mineralocorticoid effect - Na+ retention and K+ excretion

Answer 3

Immunosuppression - increases the risk and severity of infection - alters host response Increased catabolism - proximal muscle weakness, skin thinning with easy bruising and gastritis Mood and behavioural changes - insomnia, confusion, psychosis Hypertension, hypokalaemia and oedema Suppresses ACTH production - in prolonged treatment leads to adrenal atrophy If steroids are withdrawn too quickly - Addisonian crisis Needs to be withdrawn slowly by can cause symptoms of chronic glucocorticoid deficiency Cannot produce cortisol secretion in response to stress - needs to be provided artificially in acute illness (double dose)

Answer 4

§ Those with infection | § Children

Answer 5

Peptic ulcers and GI bleeding - especially if used with NSAIDs Hypokalaemia enhancement with those on Beta-2 agonists, theophylline (PDE inhibitor), loop and thiazide diuretics Efficacy reduced by cytochrome P450 inducers (phenytoin, carbamazepine, rifampcin)

Answer 6

Used in beta blocker and Calcium Channel Toxicity Severe acute hypocalcaemia or hypocalcaemic tetany Acute severe hyperkalaemia (plasma-potassium concentration above 6.5 mmol/litre or in the presence of ECG changes) Calcium deficiency, Mild asymptomatic hypocalcaemia Hyperkalaemia is common among hospital inpatients First line emergency treatment for severe hyperkalaemia associated with ECG abnormalities

Answer 7

10mL of calcium gluconate 10% IV over 10-15 minutes

Answer 8

○ In hyperkalaemia - calcium raises the myocardial threshold potential, reducing excitability and the risk of arrhythmias - no effect on serum potassium

Answer 9

Conditions associated with hypercalcaemia (e.g. some forms of malignant disease)

Answer 10

Prevent recurrent attacks of gout Thiazide or loop diuretics - increases serum uric acid Aspirin inhibits renal excretion of uric acid Drug-induced gout C Prevent uric acid and calcium oxalate renal stones Prevent hyperuricaemia and tumour lysis syndrome

Answer 11

Xanthine oxidase inhibitor | Xanthine oxidase metabolises xanthine from purines to uric acid

Answer 12

Initially can worsen gout attacks - can be prevented with co-prescription with an NSAIDs or colchicine during initiation of treatment Allopurinol hypersensitivity syndrome - rare Can cause Stevens-Johnson Syndrome or toxic epidermal necrolysis

Answer 13

Shouldn't be started during acute attacks of gout but can be continued if patient is already on it Renal and hepatic impairment

Answer 14

``` Active metabolite (mercaptopurine) - of the pro-drug azathioprine metabolised by xanthine oxidase Co-prescription with ACE inhibitors or thiazides can increase risk of hypersensitivity and with amoxicillin can increase the risk of skin rash ```

Answer 15

Recombinant form of urate-oxidase enzyme used to treat hyperuricemia following chemotherapy for leukaemias and non-Hodgkin's lymphoma. Rasburicase catalyzes enzymatic oxidation of uric acid into an inactive and soluble metabolite (allantoin). The injection of rasburicase reduces levels of uric acid and mitigates the toxic effects of chemotherapy induced tumour lysis

Answer 16

G6PD deficiency

Answer 17

Atopic Allergies

Answer 18

Diarrhoea, fever, headache, nauseas, skin reactions, vomiting Haemolytic anaemia, hypersensitivity, hypotension

Answer 19

Antipseudomonal penicillins -> reserved for severe infections (antibiotic resistance or in immunocompromised (neutropenic) individuals) Tazobactam is the beta - lactamase inhibitor (confers activity against beta-lactam producing Staphylococcus aureus and gram-negative anaerobes) Clinical infections treated: LRTIs UTIs Intraabdominal sepsis Skin and soft tissue infections

Answer 20

Responsible for cross-linking peptidoglycan in bacterial cell walls - weakens walls preventing them from maintaining their osmotic gradient

Answer 21

GI upset - nausea and diarrhoea Clostridium difficile Rare- antibiotic - associated colitis

Answer 22

Cautioned in those with a C. difficile infection Contraindicated in penicillin allergy People with penicillin allergy would react to cephalosporins and other B-lactam antibiotics

Answer 23

Pencillins reduce renal excretion of methotrexate - can increase toxicity Enhance anticoagulant effects of warfarin by killing normal GI flora that synthesise vitamin K Each dose of piperacillin - tazobactam contains 11mmol Na+ and is infused in 50-150mL fluid - needs to be considered when prescribing fluids in heart failure patients

Answer 24

Used to treat severe infections - caused by gram-negative aerobe (including pseudomonas aerunginosa): □ Severe sepsis □ Pyelonephritis and complicated UTIs □ Biliary and other intraabdominal sepsis □ Endocarditis Topical - bacterial skin and ear infections

Answer 25

Has a very narrow therapeutic index - little safety margin between clinically effective dose and toxic dose - aminoglycosides distribute through body water not fat - needs to be the basis of the dosage given Warnings: □ Renally excreted □ Not be given in patients with myasthenia gravis □ Neonates, elderly patients and those with renal impairment

Answer 26

Mechanism of Action Against gram-negative aerobic bacteria - some activity against staphylococci and mycobacteria - other agents preferred in practice Inactive against streptococci and anaerobes - need to be combined with penicillin and/or metronidazole - when organism is unknown Binds irreversibly to bacterial ribosomes (30S subunit) - inhibit protein synthesis -inhibit protein synthesis Are bactericidal As pencillins weaken bacterial cell walls - may enhance aminoglycoside - increase bacterial uptake via oxygen - dependent transport system which streptococci and anaerobic bacteria don't have

Answer 27

Nephrotoxicity (reduced urine output and rising serum creatinine and urea) can be reversible and otoxicity (hearing loss, tinnitus or vertigo) is irreversible - accumulate in tubular epithelial cells and cochlear and vestibular hair cells - trigger apoptosis and cell death

Answer 28

Ototoxicity more likely if co-prescribed with loop diuretics (e.g. furosemide) or vancomycin Nephrotoxicity more likely is co-prescribed with ciclosporin, platinum chemotherapy, cephalosporins or vancomycin

Answer 29

COPD - short acting muscarinics - relieve breathlessness (brought on by exercise or during exacerbations) LAMAS - used to prevent breathlessness and exacerbations Asthma - short-acting anti-muscarinic used to help relieve breathlessness during acute exacerbations (added to a short -acting beta-2- agonist e.g. salbutamol). LAMAs (tiotroprium) - added to high dose inhaled corticosteroids and long-acting beta-2 agonists (LABA) as maintenance treatment - patients 1 or more severe asthma exacerbations in the past year

Answer 30

Ipratropium, tiotropium, Glycopyrronium, Aclidinium

Answer 31

Competitive inhibitor of acetylcholine Reduce smooth muscle tone, including the respiratory tract and bladder and reduce secretions from the glands in the respiratory and GI tracts Relaxation of the pupillary constrictor and ciliary muscles - pupil dilation + prevent accommodation No advantaged in prescribing more than 4 times daily

Answer 32

Inhaled - rapidly metabolised - less effects Nasopharyngitis, sinusitis and cough, GI disturbance (including dry mouth and constipation and urinary retention, blurred vision and headaches)

Answer 33

Cautioned in patients with - angle - closure glaucoma (can cause a rise in intra-ocular pressure) Cautioned in patients with urinary retention and arrhythmias

Answer 34

Asthma - SABAs relieve breathlessness LABAs used in chronic asthma when inhaled corticosteroids are insufficient - need to be given with inhaled corticosteroids COPD - SABAs relieve breathlessness LABAs 2nd line therapy of COPD - improve symptoms and reduce exacerbations Hyperkalaemia - neubulised used to lower serum potassium (given along with insulin and glucose and calcium gluconate to stabilise the myocardium)

Answer 35

Smooth muscles relaxation - G - protein coupled receptors Stimulate Na+/K- ATPase pumps on cell surface - K+ shifts from extracellular to intracellular compartments Useful adjunct in hyperkalaemia - not used in isolation

Answer 36

Flight or fight - tachycardia, palpitations, anxiety and tremor Glycogenolysis - increase serum glucose High dose - serum lactate goes up Long term - muscle cramps

Answer 37

LABA - only used with an inhaled corticosteroid | Cautioned in those with CVS risks - can induce tachycardias or arrhythmias

Answer 38

Beta-blockers High nebulised doses of beta - 2 agonists with theophylline and corticosteroids - lead to hypokalaemia - serum K+ needs to be monitored

Answer 39

Indicate whether the nebuliser should be driven by oxygen or air Oxygen should be used in asthma whereas medical air should be used in COPD - due to risk of CO2 retention

Answer 40

Asthma - treat airway inflammation (usually combined with SABA) COPD - Control symptoms and prevent exacerbations - people with severe airway obstruction on spirometry and recurrent exacerbations (usually combined with a LABA)

Answer 41

Reduction in mucosal inflammation, widens the airways and reduced mucus secretion

Answer 42

Immunosuppression - oral candidiasis - need to rinse mouth after use Hoarse voice in COPD High dose - release into systemic - adrenal suppression, growth retardation and osteoporosis

Answer 43

Cautioned at a high - dose in patients with a history of pneumonia and in children at risk of growth suppression

Answer 44

Adults: Add on if not controlled well by inhaled corticosteroids and LABAs Children 5-12: alternative to LABAs where inhaled corticosteroids are insufficient Children under 5 years: 1st line preventative therapy in young children with asthma who cannot take steroids

Answer 45

Blocking the CysLT1 receptor and damping down the inflammatory cascade

Answer 46

Usually well-tolerated Mild Headache and abdominal pain Increased rate of URTIs Rare- hyperactivity

Answer 47

Not prescribed unless incompletely controlled with inhaled corticosteroids and LABAs

Answer 48

Cardiac Arrest - Advanced Life Support - treatment algorithm for shockable and non-shockable rhythms Anaphylaxis Injected directly into tissues to induce local vasoconstriction - used in endoscopy to control mucosal bleeding - sometimes mixed with local anaesthetic to control mucosal bleeding - sometimes mixed with local anaesthetic drugs (e.g. lidocaine) to prolong local anaesthetic

Answer 49

Restoration os cardiac output - followed by adrenaline -induced hypertension When given to conscious patients in anaphylaxis or in an attempt to produce local vasoconstriction - often causes anxiety, tremor, headache and palpitations Patients with existing heart problems - angina, MI and arrhythmias

Answer 50

None in cardiac arrest or anaphylaxis For local vasoconstriction - should be given with caution in patients with heart disease Adrenaline - anaesthetic preparations should not be given in areas supplied by an end-artery - fingers and toes - can cause tissue necrosis

Answer 51

In patients on beta-blockers - may induce widespread vasoconstriction

Answer 52

None in cardiac arrest or anaphylaxis For local vasoconstriction - should be given with caution in patients with heart disease Adrenaline - anaesthetic preparations should not be given in areas supplied by an end-artery - fingers and toes - can cause tissue necrosis

Answer 53

Allergy Relief pruritis and hives (urticaria) due to insect bites, infections and drug allergies Adjunct treatment in anaphylaxis after administration of adrenaline Other class used in nausea and vomiting

Answer 54

1st generation antihistamine (e.g. chlorophenamine) cause sedation - histamine has a role in wakefulness 2nd generation antihistamine (e.g. loratadine, cetirizine and fexofenadine) do not cross the blood - brain barrier - have fewer adverse effects

Answer 55

Mainly safe | Cautioned in patients with severe liver disease - may precipitate hepatic encephalopathy

Answer 56

As a first line diagnostic and therapeutic agent in supraventricular tachycardia (SVT), usually evident on the ECG as a regular, narrow - complex tachycardia

Answer 57

Adenosine is an agonist of adenosine receptors on cell surfaces. In the heart, activation of these G-protein coupled receptors induces severe effects, including reducing the frequency of spontaneous depolarisation (automacity) and increasing resistance to depolarisation (refractoriness) In turn, this transiently slows the sinus rate and conduction velocity and increases the AV node refractoriness. Many forms of SVT arise from a self-perpetuating electrical (re-entry) circuit that takes in the AV node Increasing refractoriness in the AV node breaks the re-entry circuit, which allows normal depolarisations from the sinoatrial (SA) node to resume control of heart rate (cardioversion). Where the circuit does not involve the AV node (e.g. in atrial flutter), adenosine will not induce cardioversion. However by blocking conduction to the ventricles, it allows closer inspection of the atrial rhythm on the ECG This may reveal the diagnosis The duration of effect of adenosine is very short because it is rapidly taken up by cells (e.g. red cells) Its half-life in plasma is less than 10 seconds

Answer 58

Can induce bradycardia and even asystole Deeply unpleasant sensation for the patient Sinking feeling in the chest - accompanied by breathlessness and a 'sense of impending doom' Usually short-lived

Answer 59

Should not be administered to patients that cannot tolerate its transient bradycardic effects e.g. those with hypotension, coronary ischaemia, decompensated heart failure Adenosine may induce bronchospasm in susceptible individuals so should be avoided in patients with asthma or COPD Patients who have had a heart transplant are very sensitive to the effects of adenosine

Answer 60

Dipyridamole, an antiplatelet agent, blocks cellular uptake of adenosine. This prolongs and potentiates its effect, so the dose of adenosine should be halved. Theophylline and aminophylline (systemic bronchodilators) are competitive antagonists of adenosine receptors and reduce its effect. Patients who have taken these drugs respond poorly and may require higher doses

Answer 61

Used to treat a wide range of tachyarrhthymias, including atrial fibrillation (AF), atrial flutter, supraventricular tachycardia (SVT), ventricular tachycardia (VT). Used when other therapeutic options (drugs or electrical cardioversion) are ineffective or inappropriate

Answer 62

Has many effects on myocardial cells, including blockade of sodium, calcium and potassium channels and antagonism of alpha and beta - adrenergic receptors. There effects reduce spontaneous depolarisation (automaticity), slow conduction velocity and increase resistance to depolarisation (refractoriness), including in the AV node. By interfering with AV node conduction, amiodarone reduces the ventricular rate in AF and atrial flutter. Through its other effects it may also increase the chance of conversion to and maintenance of sinus rhythm. In SVT involving a self-perpetuating ('re-entry') circuit that includes the AV node, amiodarone may break the circuit and restore sinus rhythm. Amiodarone's effects in suppressing spontaneous depolarisations make it an option for both treatment and prevention of VT and for improving the chance of successful defibrillation in refractory VF.

Answer 63

In acute use, compared with other anti-arrhythmic drugs, amiodarone causes relatively little myocardial depression. It can cause hypotension during IV infusion, although this is probably an effect of the solvent with which it is formulated, rather than the drug itself. When taken chronically, amiodarone has many side effects, several of which are serious. These include effects on the lungs (pneumonitis), heart (bradycardia, AV block), liver (hepatitis) and skin (photosensitivity and grey discolouration). Due to its iodine content (amIODarone) and structural similarities to thyroid hormone, it may cause thyroid abnormalities, including hypo- and hyperthyroidism. Amiodarone has an extremely long half-life. After discontinuation, it may take months to be completely eliminated

Answer 64

Amiodarone is a potentially dangerous drug that should be used only when the risk-benefit balance justifies this. It should generally be avoided in patients with increased severe hypotension, increased heart block, and increased active thyroid disease.

Answer 65

Amiodarone interacts with many drugs. Increases the plasma concentrations of digoxin, diltiazem and verapamil. This may increase the risk of bradycardia, AV block and heart failure. The doses of these drugs should be halved if amiodarone is started

Top 100 Drugs Flashcards

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