Canadian drug name.Genetic Implication.CAPITALS indicate life-threatening, underlinesindicate most frequent.StrikethroughDiscontinued.1verapamil(ver-ap-a-mil)Calan,CalanSR,IsoptinSR,Verelan,VerelanPMClassificationTherapeutic:antianginals, antiarrhythmics (class IV), antihypertensives, vas-cular headachesuppressantsPharmacologic:calcium channel blockersPregnancy Category CIndicationsManagement of hypertension, angina pectoris, and/or vasospastic (Prinzmetal’s) an-gina. Management of supraventricular arrhythmias and rapid ventricular rates inatrial flutter or fibrillation.UnlabeledUse:Prevention of migraine headache.ActionInhibits the transport of calcium into myocardial and vascular smooth muscle cells,resulting in inhibition of excitation-contraction coupling and subsequent contrac-tion. Decreases SA and AV conduction and prolongs AV node refractory period inconduction tissue.Therapeutic Effects:Systemic vasodilation resulting in de-creased BP. Coronary vasodilation resulting in decreased frequency and severity ofattacks of angina. Reduction of ventricular rate during atrial fibrillation or flutter.PharmacokineticsAbsorption:90% absorbed after oral administration, but much is rapidly metabo-lized, resulting in bioavailability of 20–25%.Distribution:Small amounts enter breast milk.ProteinBinding:90%.Metabolism and Excretion:Mostly metabolized by the liver (primarily byCYP3A4).Half-life:4.5–12 hr.TIME/ACTION PROFILE (cardiovascular effects)ROUTEONSETPEAKDURATIONPO1–2 hr30–90 min†3–7 hrPO-ERunknown5–7 hr24 hrIV1–5 min‡3–5 min2 hr‡†Single dose; effects from multiple doses may not be evident for 24–48 hr.‡Antiarrhythmic effects; hemodynamic effects begin 3–5 min after injection and persist for 10–20 min.Contraindications/PrecautionsContraindicated in:Hypersensitivity; Sick sinus syndrome; 2nd- or 3rd-degreeAV block (unless an artificial pacemaker is in place); Systolic BP90 mm Hg; HF,severe ventricular dysfunction, or cardiogenic shock, unless associated with supra-ventricular tachyarrhythmias; Concurrent IV beta blocker therapy.UseCautiouslyin:Severe hepatic impairment (doseprecommended);Historyofserious ventricular arrhythmias or HF;Geri:Dosep/slower IV infusion rates recom-mended (qrisk of hypotension);OB,Lactation:Safety not established.AdverseReactions/Side EffectsCNS:abnormal dreams, anxiety, confusion, dizziness/lightheadedness, drowsiness,extrapyramidal reactions, headache, jitteriness, nervousness, psychiatric distur-bances, weakness.EENT:blurred vision, disturbed equilibrium, epistaxis, tinnitus.Resp:cough, dyspnea, shortness of breath.CV:ARRHYTHMIAS,HF, bradycardia,chest pain, hypotension, palpitations, peripheral edema, syncope, tachycardia.GI:qliver enzymes, anorexia, constipation, diarrhea, dry mouth, dysgeusia, dyspepsia,nausea, vomiting.