Cardiovascular drugs

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Cardiovascular drugs
2010-05-01 22:44:27
Step board exam physicians

cardio drugs for step 1 of the usmle
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  1. Spironolactone
    Treats HTN & CHF: K+-sparing diuretic that competitively inhibits aldosterone receptors in distal nephron. (These would tell you to absorb Na+ & waste K+?) Don't give if person has elevated T waves (hallmark for high K+, which can be from renal failure, rhabdomyolysis, hemolysis, etc). SE's: gynecomastia b/c also blocks androgen receptors
  2. Minoxidil
    Dilates vascular smooth muscle by opening K+ channels. For refractory HTN. Hypertrichosis, pericardial effusion, salt & water retention.
  3. Diazoxide
    Opens K+ channels for vasodilation. Used for HTN emergencies. Also inhibits insulin release from pancreas --> hyperglycemia. Opposite of thiazide diuretic: Na+ & water retention.
  4. Sodium nitroprusside
    Vasodilates via cGMP --> NO (both arterioles & venules). Given via IV for acute HTN, CHF. SE: cyanide toxicity, & excess vasodilation can cause hypotension, diaphoresis, anxiety, palpitations.
  5. Verapamil, nifedipine, diltiazem
    Ca++ channel block (from both outside & within smooth muscle). SE's: AV block (V & D), exacerbated CHF, dizziness, HA. Nifedipine similar to Nitrates (mainly vascular effect); verapamil similar to B-blockers (acts mainly on heart)
  6. Captopril, elanapril, fosinopril
    ACE inhibitors. SE's: dry cough (b/c inhibits bradykinin breakdown), hyperkalemia (inc'd renin), taste changes. Bad for pregnancy - fetal renal damage. Captopril slows CHF progression by inhibiting ventricular remodeling.
  7. Losartan
    ARB (angiotensin II receptor blocker). Like ACE inhibitors, hyperkalemia & fetal renal damage... but no dry cough (b/c bradykinin breakdown not affected) or altered taste.
  8. Quinidine, procainamide, disopyramide
    Class IA anti-arrhythmic (Na+ channel block during Phase 0 depolariz): prolongs AP conduction in bundle of His & Purkinje, also decreases automaticity of ventricular cells --> prolongs QRS & QT. For: Atrial arrhythmias, ventricular ectopic beats (disopyramide esp). SE's: HA, GI disturbance, cinchonism (tinnitus & blurred vision), torsades de pointes (b/c prolonged QT). Procainamide also causes agranulocytosis, neutro- & thrombocytopenia. Must pre-treat w/b-blocker, Ca++ channel blocker, or digitalis to slow ventricular response.
  9. SLE induced by drugs
    Procainamide & quinidine (class IA antiarrhythmics), hydralazine (alpha-1 blocker), methyldopa, isoniazid. See ANA & anti-histone Ab's, but not anti-dsDNA.
  10. Lidocaine, Tocainide, Mexiletine
    Class IB antiarrhythmics: shorten repolarization by blocking inactivated Na+ channels --> dec'd AP duration. Only for ventricular arrhythmias b/c doesn't affect SA or AV nodes (they use Ca++ for repolarization phase 3!). Also local anesthestic. SE's: CNS (sedation, seizures).
  11. Flecainide, encainide, propafenone, and moricizine
    Class IC antiarrhythmics: depress Phase 0 (fast depolarization) by strongly binding Na+ channels. Slow impulse conduction everywhere in heart; limited to life-threatening arrhythmias. Can lead to sudden death.
  12. Class II antiarrhythmics
    Not Burger King Chicken (for classes I-IV). So, Class II = B-blockers: dec SA node firing, inhibit conduction through AV node - so, good for atrial (supraventricular) tachyarrhythmias. Ex. propanolol, acebutolol. SE's: bronchospasm in asthmatics, nightmares/hallucinations, diarrhea. Metoprolol can cause dyslipidemias, but it has great B-1 selectivity, so less risk of bronchospasm. Names A-M = B-1 selective.
  13. Bretylium
    Class III antiarrhythmic = Block K+ channels, so repolarization takes longer. Use after trying Class IA & IB drugs for ventricular arrhythmia -- b/c this drug initially worsens it. SE's: hypotension (b/c block effector part of baroreceptor reflex), nausea, vertigo, dizziness.
  14. Amiodarone
    Class III antiarrhythmic, use limited by toxicity. Causes pulm fibrosis/alveolitis, GI probs, hypo or hyperthyroid, bluish skin spots & photosensitivity
  15. Sotalol
    Both Class II & III antiarrhythmic characteristics. Only for life-threatening ventricular tachyarrhythmias; it may worsen them. SE's: think B-blocker.
  16. Class IV antiarrhythmics
    • Diltiazem, verapamil. Block Ca++ channels, so slowed AP upstroke in AV node and slowed plateau phase (2) -- use for supraventricular tachycardia to protect the ventricles. SE's: AV block, asystole.
    • For CHF pts: Verapamil acts the most on the heart, so it'll exacerbate CHF. Diltiazem also has mild negative inotropic effects. But amlodipine, felodipine, & isradipine are fine; the first 2 might even help.
  17. Cardiac glycosides
    • Digoxin, digitoxin. Inhibit Na+/K+ ATPase --> more intracellular Na+ --> inhibits Na+/Ca++ exchanger --> more intracellular Ca++. Pos inotropy; also enhances vagal activity at AV node. Can cause ventricular arrhythmias via accessory pathway conduction. Uses: CHF, supraventricular tachyarrhythmias.
    • SE's: life-threatening arrhythmias, GI, CNS (delirium, hallucinations), altered color perception. Toxicity worse w/hypokalemia, hyponatremia, hypercalcemia. For toxicity, use digoxin-immune Fab.
  18. Nitroglycerin
    Vasodilation via cGMP --> NO. Coronary vasodilation, dec'd preload via venodilation & systemic venous pooling. Used for: angina (but MI won't respond), HTN (it also dec's afterload). SE's: postural hypotension/reflex tachycardia, HA.
  19. Angina sx
    Crushing chest pain (may radiate to L arm/neck). May also have nausea, vomiting, diaphoresis, SOB. Responds to sublingual nitroglycerin. Use B-blockers, but NOT acebutolol or pindolol -- may exacerbate.
  20. Niacin
    Decreases vLDL production by liver. SE's: pruritis, flushing, hyperpigmentation, GI, inc'd liver enzyme levels/ hyperuricemia/hyperglycemia.
  21. Clofibrate, Gemfibrozil
    Inc'd lipoprotein lipase activity -- breaks down triglycerides (in vLDL) --> FA's, so dec'd vLDL. Also inhibits cholesterol synthesis in liver & inc's excretion into bile. SE's - clofibrate: cholelithiasis, cholecystitis, need to monitor prothrombin time; not with pregnancy, liver or kidney insufficiency. SE's -- gemfibrozil: gallstones.
  22. Cholestyramine, colestipol
    Increase bile acid excretion in feces, so must convert cholesterol into bile acids instead. SE's: nausea, constipation, cramping, steatorrhea/ impaired absorption of fat-soluble vitamins.
  23. Lovastatin & mevastatin
    HMG CoA reductase inhibitors --> dec'd cholesterol synthesis --> inc'd breakdown of circulating LDL (and inc'd HDL). SE's: GI, HA, rash, inc'd liver enzymes, rhabdomyolysis
  24. Streptokinase, urokinase, tPA
    Convert plasminogen --> plasmin for clotting. Used for acute MI
  25. Epinephrine
    Injected: for acute asthmatic attacks, hypersensitivity reactions. Stimulates: alpha-adrenergic receptors (vasoconstriction), beta-1 (pos inotropy & chronotropy of heart), beta-2 (bronchodilation via cAMP, dec'd mast cell secretion). SE's: all the anxiety sx (tachy, palpitations, anxiety, diaphoresis, tremor). Don't use in pts >60 b/c or anyone with cerebrovascular insufficiency.
  26. Ephedrine
    Vs. epinephrine: ephedrine is much less potent w/longer duration of action. For chronic asthma. Stimulates both alpha- and beta-adrenergic receptors, & increases norepinephrine release. SE's: CNS stimulation (nervous, insomnia).
  27. Isoproterenol
    Acts mainly on B-1 and B-2 (stimulates cAMP production) -- rarely used now that more B-2 selective agents are available for asthma attacks. SE's: similar to epinephrine, but less -- tachycardia, diaphoresis, flushing, dizziness, nausea, arrhythmias.
  28. Metaproterenol
    B2-selective agonist; minimal systemic SE's b/c inhaled (can also be oral); better bioavailability b/c more resistant to COMT methylation (same as the other B2 agonists). Relaxes smooth muscle of bronchi + uterus and skeletal muscle vasculature. SE's: same as other sympathetic activators -- tachy, nervousness, tremor, palpitations, HTN.
  29. Terbutaline
    More B2-selective when given orally; cardiac SE's when injected. Given via IV for status asthmaticus. SE's rare: nervousness, palpitations, dizziness, tinnitus.
  30. Albuterol
    B2-selective for asthma, oral or inhaled. Same sympathetic SE's: nervous, tremor, tachy, palpitations. Caution in pts taking MAOI's or TCA's. It has the least B1-stimulation of any.
  31. Methylxanthines
    Theophylline, theobromine, aminophylline, caffeine... for bronchodilation. MOA: Inc'd cAMP & Ca++, plus blockade of adenosine receptors.
  32. Theophylline
    Bronchodilation, improved diaphragm contractility, positive inotropy, CNS stimulation. Used for asthma & COPD. Oral, rectal, or IV. SE's: nervous, dizzy, nausea, vomiting. IV form = seizures, cardiac arrest, arrhythmias (b/c adenosine receptor block = AV node block).
  33. Cromolyn sodium inhalers & nedocromil
    Inhibit mast cell degranulation -- will only prevent asthma attacks. SE's minimal: sore throat, dry mouth, cough. (Rare: urticaria, gastroenteritis, maculopapular dermatitis)
  34. Prednisone, prednisolone
    For severe bronchospasm, both acute & chronic. Dec'd airway inflamm & edema, plus bronchodilation (potentiates effects of adrenergic agonists). Try to taper from oral --> inhaled. SE's: growth & adrenocortical suppression, exacerbation of DM, osteoporosis, AVN, psychosis/dysphoria.
  35. Beclomethasone dipropionate
    For severe asthma. Steroid, but inhaled, so systemic SE's rare. SE's: sore throat, dry mouth, oral Candida infection (rinse mouth).
  36. Atropine, ipratropium bromide
    Anticholinergics, since ACh causes bronchoconstriction. For asthma pts unresponsive to the other drug classes. SE's: constipation, dry mouth, urinary retention, sedation -- less w/ipratropium b/c it doesn't cross BBB. M2 anticholinergic: inc HR, but no effect upon MAP. M3: no effect upon HR.
  37. Zileuton
    Anti-leukotriene synthesis. Use for asthma, with steroids. SE's: diarrhea, HA.
  38. Ezetimibe
    Blocks intestinal cholesterol absorption (for heart disease). Dec'd LDL's. SE's: rarely, inc'd LFT's.
  39. Phentolamine
    Alpha-antagonist: decreases SVR --> inc'd HR (baroreceptor reflex).
  40. HTN in pregnancy
    Methyldopa -- alpha-2 agonist to reduce sympathetic outflow -- and hydralazine (arteriolar vasodilation via cGMP). Not diuretics, b/c hypovolemia --> dec'd uterine blood flow. Also, ARB's & ACE inhibitors cause fetal defects.