Mr. Eknath Kole M.S. Pharm (NIPER Mohali)

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1 M.S. Pharm (NIPER Mohali) Drug Class Actions Therapeutic Uses Pharmacokinetics Adverse Effects Other Quinidine IA -Binds to open and inactivated Na+ -Decreases the slope of Phase 4 spontaneous depolarization -Inhibits K+ channels -Mild α-adrenergic blocking action -Atropine-like effect -Atrial tachy -Av-junctional tachy - Ventricular -Maintains sinus rhythm after direct-current cardioversion -Prevent frequent ventricular -Rapidly and completely absorbed after oral administration - Extensive metabolism by CYP450 -Polymorphic ventricular tachy (torsades de pointes) -SA and AV block -Asystole -Toxic: ventricular -Nausea -Vomiting -Diarrhea -Cinchonism (blurred vision, tinnitus, headache, disorientation, psychosis) -Has class III activity as well -Cardiotoxic effects are exacerbated by hyperkalemia - Increases steadystate concentration of DIGOXIN by displacing it from tissues and decreasing its renal clearance Procainamide IA -Binds to open and inactivated Na+ -NAPA: prolongs the duration of the action potential (class III actions) -Well absorbed after oral administration -1/2 life: 2-3 hours -Acetylated in liver to NAPA -NAPA eliminated via kidneys -SLE like syndrome -Asystole -Ventricular -Depression -Hallucination -Psychosis -Dosage needs to be adjusted in patients with renal failure Disopyramide IA -Binds to open and inactivated Na+ -Negative inotropic effect (decrease in contractility) is stronger than QUINDINE and PROCAINAMIDE -Peripheral vasoconstriction -Ventricular -50% excreted in urine unchanged -30% of the drug converted by liver to mono-n-dealkylated metabolite -Dry mouth -Urinary retention -Blurred vision -Constipation -Has Class III activity

2 M.S. Pharm (NIPER Mohali) Lidocaine IB -Rapidly associates and dissociates from NA+ channels -Actions are manifested when cardiac cell is depolarized or firing rapidly - Shortens Phase 3 repolarisation and decreases the duration of AP -Ventricular arising during myocardial ischemia -Given via IV due to extensive 1 st pass metabolism -Wide therapeutic index -Drowsiness -Slurred speech -Paresthesia -Agitation -Confusion -Convulsions -Local anesthetic - Dose should be adjusted in people with liver dysfunction -Cardiac Mexiletine Tocainide IB -Shortens Phase 3 repolarisation and decreases the duration of AP -Mexiletine: chronic tx of ventricular associated w/ previous MI Tocainide: tx of ventricular tachy -Tocainide: pulmonary toxicity leading to pulmonary fibrosis Flecainide IC -Slowly dissociate from resting Na+ channels -Prominent effects even at normal heart rates -Suppresses Phase ) upstroke in Purkinje and myocardial fibers Slowing of conduction in all cardiac tissue -Automaticity is reduced by an increase in the threshold potential -Refractory ventricular -Prevention of paroxysmal atrial fibrillation/flutter - Paroxysmal -Suppresses premature ventricular contraction -Absorbed orally -1/2 life: hours -Dizziness -Blurred vision -Headache -Nausea -Aggravates pre-existing -Induces ventricular -Negative inotropic effects can aggravate CHF Propafenone IC -Slows conduction in all cardiac tissues -Broad spectrum antiarrhythmic agent

3 M.S. Pharm (NIPER Mohali) β-antagonists Propranolol Metoprolol Esmolol II -Diminish Phase 4 depolarization depressing automaticity, prolonging AV conduction and decreasing HR and contractility -Tachy caused by increased sympathetic activity - Atrial flutter and fibrillation -AV-nodal re-entrant -Esmolol: acute during surgery or emergency situations -Propranolol: reduces incidence ofsudden arrhythmic death after MI -Metoprolol: reduces the risk of bronchospasm; most widely used in treatment of cardiac Amiodarone III -Prolongs the action potential duration and the refractory period -Severe refractory and ventricular tachy -Incompletely absorbed after oral administration -Prolonged ½ life of several weeks -Interstitial pulmonary fibrosis -GI intolerance -Tremor -Has Class I, II, IV actions as well -Also has antianginal actions -Extensive distribution in adipose tissue -Full clinical effects achieved 6 weeks after initiation of therapy -Ataxia -Dizziness -Hyper- or hypothyroidism -Liver toxicity -Photosensitivity -Neuropathy -Muscle weakness -Blue skin discoloration

4 M.S. Pharm (NIPER Mohali) Sotalol III -Has potent nonselective β-blocker activity (suppresses ectopic beats, reduces myocardial oxygen demand, antifibrillatory effects ) -Blocks rapid outward K+ current (delayed rectifier) prolongs both repolarisation and duration of AP Lengthening effective refractory period -Prevents recurrence of -Decreased mortality in patients with sustained ventricular -Torsade de pointes Dofetilide III -1 st line agent in pts with persistent atrial fibrillation and HF -CAD w/ impaired LV function -1/2 life 10 hours -Excreted in urine -AMIODARONE, β- BLOCKERS AND DOFETILIDE are the only antiarrhythmic drugs recommended for tx of atrial fibrillations Verapamil Diltiazem IV -Block voltage-sensitive Ca 2+ channels Decrease in slow inward current that triggers cardiac contraction Slow conduction and prolong effective refractory period -Bind only to open, depolarized channels, preventing repolarisation until the drug dissociates -Block most effectively when the heart is rapidly beating (use-dependent) -Arrhythmias that traverse Ca 2+ dependent cardiac tissues -Atrial -Reentrant -Reduce ventricular rate it atrial flutter and fibrillation -HTN -Absorbed well after oral administration - Verapamil: extensively metabolized by liver -Decrease BP -contraindicated in pts with pre-existing depressed cardiac function (due to negative inotropic effects)

5 M.S. Pharm (NIPER Mohali) -Angina Digoxin -Shortens the refractory period in atrial and ventricular myocardial cells -Prolongs the effective refractory period and diminishes conduction velocity in the AV node -Control ventricular response rate in atrial fibrillation and flutter -Ectopic ventricular beats Ventricular and fibrillation (treated with LIDOCAINE OR PHENYTOIN) Adenosine -Decreases conduction velocity -Prolongs refractory period -Decreases automaticity in the AV node -DOC: abolishing acute -Short duration of action: 15 seconds -Flushing -Chest pain -Hypotension -Naturally occurring nucleoside