Verapamil Tablet:

• Essential hypertension
• Angina pectoris and prevention of re-infarction
• Supraventricular arrhythmias

Verapamil Injection:

• Tachycardias such as: Paroxysmal supraventricular tachycardias
• Atrial fibrillation with rapid ventricular response (except WPWS)
• Atrial flutter with rapid conduction
• Extrasystoles
• Acute hypertension
• Acute coronary insufficiency

For the prophylaxis and / or therapy of ectopic arrhythmias (predominantly ventricular extrasystoles) in halothane anaesthesia and in the application of adrenaline in halothane anaesthesia respectively.

Verapamil is a calcium ion influx inhibitor that prevents the inward movement of calcium into cardiomyocytes, smooth muscle cells, and the His-Purkinje system. The tablets are formulated for sustained release of the drug in the intestine.

Verapamil is an L-type calcium channel blocker with antiarrhythmic, antianginal, and antihypertensive properties. Immediate-release verapamil has a relatively short duration of action and requires dosing 3–4 times daily. Extended-release formulations allow once-daily dosing. As verapamil has negative inotropic effects (reduces myocardial contractility), it should be used with caution in patients with severe left ventricular dysfunction or hypertrophic cardiomyopathy, as it may worsen these conditions.

Verapamil Tablet:

• The dose of Verapamil should be individualized by titration and the drug should be administered with food.
• For essential hypertension the initial dose should be given 180 mg in the morning. If adequate response is not obtained with 180 mg of Verapamil then the dose may be titrated by following manner: 240 mg each morning. 180 mg each morning plus 180 mg each evening. 240 mg every 12 hourly.
• For angina the usual dose is 80 mg to 120 mg three times a day.
• For arrythmias in digitalized patients, Verapamil should be given 240 mg to 360 mg in divided doses, depending on the severity of the condition. Divided doses up to 180 mg/day may occasionally be needed.

Verapamil Injection:

• Adults: 5 mg slowly intravenously, in tachycardias and hypertensive crises, if necessary repeat after 5 to 10 minutes. Drip infusion to maintain the therapeutic effect: 5-10 mg/hour in physiological saline, glucose, laevulose or similar solutions, on average up to a total dose of 100 mg/day.

Children:

• Newborn: 0.75-1 mg (0.3-0.4 ml)
• Infants: 0.75-2 mg (0.3-0.8 ml)
• Children age 1-5 years: 2-3 mg (0.8-1.2 ml)
• Age 6-14 years: 2.5-5 mg (1-2 ml)

of Verapamil, given intravenously, depending on age and action. The injection should be made slowly under electrocardiographic control and only until onset of the effect. Intravenous infusion in hypertensive crises: initially 0.05-0.1 mg/kg/hour; if the effect proves to be insufficient, the dose is increased at 30-60 minute intervals until twice the dose or more is reached. Average total dose up to 1.5 mg/kg/day.

May increase plasma level with CYP3A4 inhibitors (e.g. erythromycin, ritonavir), cimetidine. May decrease plasma level with CYP3A4 inducers (e.g. rifampicin), phenobarbital, sulfinpyrazone. Increased risk of bleeding with aspirin. May increase bradycardic and hypotensive effect with telithromycin. Increased AV blocking effect with clonidine. May increase plasma level of cardiac glycosides (e.g. digoxin, digitoxin), β-blockers (e.g. propranolol, metoprolol), α-blockers (e.g. terazosin, prazosin), immunosuppressants (e.g. sirolimus, ciclosporin, tacrolimus, everolimus), lipid lowering agents (e.g. lovastatin, simvastatin, atorvastatin), colchicine, quinidine, carbamazepine, imipramine, glibenclamide, doxorubicin, midazolam, buspirone, almotriptan, theophylline. May potentiate hypotensive effect with diuretics, antihypertensives, vasodilators. May increase neurotoxic effect of lithium.

• Severe left ventricular dysfunction.
• Hypotension or cardiogenic shock.
• Sick sinus syndrome (except in patients with a functioning artificial pacemaker).
• Second or third-degree atrioventricular (AV) block (except in patients with a functioning artificial pacemaker).
• Patients with atrial flutter or atrial fibrillation with accessory bypass tract (e.g. Wolff-Parkinson-White, Lown-Ganong-Levine syndrome).
• Known hypersensitivity to verapamil hydrochloride.

Verapamil is generally well tolerated. The following reactions occurred in clinical trials (≥1%):

• Digestive system: Constipation, nausea.
• Cardiovascular system: Hypotension, edema, CHF, pulmonary edema, bradycardia, AV block.
• Respiratory system: Upper respiratory tract infections.
• Nervous system: Dizziness, headache, fatigue.
• Skin: Rash, flushing.
• Hepatic: Elevated liver enzymes.

There are no adequate and well-controlled studies in pregnant women. Use only if clearly needed. Verapamil crosses the placental barrier and is detectable in umbilical blood. It is excreted in breast milk; therefore breastfeeding should be discontinued during treatment.

Use caution in 1st degree AV block, bradycardia <50 bpm, hypotension <90 mmHg, atrial fibrillation/flutter with pre-excitation (WPW syndrome), and heart failure (previous compensation required). May impair ability to drive or operate machinery, especially initially or with alcohol. Alcohol elimination is prolonged.

Treatment is supportive. Beta-adrenergic stimulation or IV calcium may improve calcium influx and be useful in overdose. Verapamil is not dialyzable.

Calcium-channel blockers

Do not store above 30°C. Keep away from light and out of reach of children.