Top 100 Drugs I Flashcards
(55 cards)
How does adenosine treat SVT?
Agonist of adenosine receptors on cell surfaces
Reduces automaticity
Increases AV node refractoriness
Breaks re-entry circuit
What is the mechanism of action of adrenaline?
Potent agonist of alpha 1 and 2 and beta 1 and 2 receptors.
Vasoconstriction of vessels supplying skin, mucosa and abdominal viscera (a1)
Increase HR, contractility and myocardial excitability (b1)
Vasodilatation of vessels supplying the heart and muscles (b2)
Bronchodilation (b2)
Suppression of inflammatory mediators from mast cells (b2)
What are indications for adrenaline?
- Cardiac arrest
- Anaphylaxis
- Local vasoconstriction (reduce bleeding, prolong local anaesthesia)
Treatment of anaphylactic shock in adults and children > 12 y/o?
Adrenaline 500mg IM
Hydrocortisone 200mg
Chlorphenamine 10mg
Important adverse effects of spironolactone?
Hyperkalemia Gynaecomastia Liver impairment Jaundice SJS
Examples of drugs that antacids may interfere absorption?
ACEIs Levothyroxine Bisphosphonates Abx e.g. cephalosporins Digoxin
Important adverse effects of allopurinol?
Skin rash, SJS, TEN
Drug hypersensitivity syndrome
Why does allopurinol increase toxicity of mercaptopurine/azathioprine?
They require xanthine oxidase for metabolism
Indications for aminoglycosides? e.g. gentamicin
Severe sepsis
Pyelonephritis and complicated UTI
Biliary and intra-abdominal sepsis
Endocarditis
Why are streptococci and anaerobic bacteria resistant to aminoglycosides?
Aminoglycosides require an oxygen-dependent transport system to enter bacterial cells, which streptococci and anaerobics lack
What is the MoA of amiodarone?
Blocks sodium, potassium and calcium channels
Antagonism of alpha and beta receptors
Reduces automaticity, slows conduction velocity, increases refractoriness
What are some examples of amiodarone SEs?
Hypotension Pneumonitis, pulmonary fibrosis Bradycardia, AV block Photosensitivity, grey discolouration Cataracts, optic neuritis Thyroid abnormalities
Indications for ACEIs?
Hypertension
Chronic heart failure
Ischaemic heart disease
Diabetic nephropathy and CKD (reduces proteinuria)
What is MoA of ACEI?
Blocks conversion of angiotension I to angiotensin II, which reduces vasoconstriction, reduces production and release of aldosterone and dilates efferent arterioles
Main side effects of ACEIs?
(First-dose) hypotension Dry cough Hyperkalemia Renal failure Angioedema Anaphylactoid reactions
What is the MoA of ARBs?
Blocks action of ATII on AT1 receptor
What are indications for SSRIs?
Moderate to severe depression (and mild depression if psychological tx fails)
Panic disorder
OCD
How are SSRIs different to TCAs?
Both block reuptake of serotonin & similar efficacy
BUT
TCA blocks uptake of noradrenaline and other receptors leading to more SEs and is more dangerous in overdose
Important side effects of SSRIs?
GI upset Appetite and weight disturbance Hyponatremia (especially in elderly) Suicidal thoughts and behaviour may be increased Lowers seizure threshold Prolonged QT interval Bleeding Serotonin syndrome
What is serotonin syndrome?
TRIAD
Autonomic hyperactivity
Altered mental state
Neuromuscular excitation
What happens if patient suddenly stops SSRI treatment?
Withdrawal:
- GI upset
- Influenza-like symptoms
- Sleeplessness
Indications for TCAs?
2nd line for moderate to severe depression
Neuropathic pain e.g. diabetic neuropathy
What is MoA for TCAs?
Blocks reuptake of serotonin and noradrenaline
Blocks wide array of receptors including muscarinic, histamine (H1), alpha 1 and 2 and dopamine (D2) receptors
What are important adverse effects of TCAs?
Antimuscarinic- dry mouth, constipation, urinary retention, blurred vision
H1 and alpha 1 block: sedation, hypotension
Arrhythmias, ECG changes, prolonged QTc, convulsions, hallucinations, sexual dysfunction, extra-pyramidal symptoms
