verelan

Essential Hypertension The dose of verapamil hydrochloride sustained-release capsules should be individualized by titration. The usual daily dose of sustained-release verapamil, verapamil hydrochloride sustained-release capsules, in clinical trials has been 240 mg given by mouth once daily in the morning. However, initial doses of 120 mg a day may be warranted in patients who may have an increased response to verapamil (e.g., elderly, small people, etc.). Upward titration should be based on therapeutic efficacy and safety evaluated approximately 24 hours after dosing. The antihypertensive effects of verapamil hydrochloride sustained-release capsules are evident within the first week of therapy. If adequate response is not obtained with 120 mg of verapamil hydrochloride sustained-release capsules, the dose may be titrated upward in the following manner: (a) 180 mg in the morning. (b) 240 mg in the morning. (c) 360 mg in the morning. (d) 480 mg in the morning. Verapamil hydrochloride sustained-release capsules are for once-a-day administration. When switching from immediate-release verapamil to verapamil hydrochloride sustained-release capsules, the same total daily dose of verapamil hydrochloride sustained-release capsules can be used. As with immediate-release verapamil, dosages of verapamil hydrochloride sustained-release capsules should be individualized and titration may be…

Serious adverse reactions are uncommon when verapamil HCl therapy is initiated with upward dose titration within the recommended single and total daily dose. See WARNINGS for discussion of heart failure, hypotension, elevated liver enzymes, AV block, and rapid ventricular response. Reversible (upon discontinuation of verapamil) non-obstructive, paralytic ileus has been infrequently reported in association with the use of verapamil. In clinical trials involving 285 hypertensive patients on verapamil hydrochloride sustained-release capsules for greater than 1 week the following adverse reactions were reported in greater than 1.0% of the patients: Constipation 7.4% Headache 5.3% Dizziness 4.2% Lethargy 3.2% Dyspepsia 2.5% Rash 1.4% Ankle Edema 1.4% Sleep Disturbance 1.4% Myalgia 1.1% In clinical trials of other formulations of verapamil HCl (N=4,954) the following reactions have occurred at rates greater than 1.0%: Constipation 7.3% Dizziness 3.3% Nausea 2.7% Hypotension 2.5% Edema 1.9% Headache 2.2% Rash 1.2% CHF/Pulmonary Edema 1.8% Fatigue 1.7% Bradycardia (HR<50/min) 1.4% AV block-total 1°, 2°, 3° 1.2% 2° and 3° 0.8% Flushing 0.6% Elevated Liver Enzymes (See WARNINGS ) In clinical trials related to the control of ventricular response in digitalized patients who had atrial fibrillation or atrial flutter, ventricular rate below 50/min at rest occurred in 15% of patients and…

Verapamil HCl is contraindicated in: Severe left ventricular dysfunction. (See WARNINGS . ) Hypotension (less than 90 mm Hg systolic pressure) or cardiogenic shock. Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker). Second- or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker). Patients with atrial flutter or atrial fibrillation and an accessory bypass tract (e.g., Wolff-Parkinson-White, Lown-Ganong-Levine syndromes). (See WARNINGS . ) Patients with known hypersensitivity to verapamil hydrochloride.

There is no specific antidote for verapamil overdosage; treatment should be supportive. Delayed pharmacodynamic consequences may occur with sustained-release formulations, and patients should be observed for at least 48 hours, preferably under continuous hospital care. Reported effects include hypotension, bradycardia, cardiac conduction defects, arrhythmias, hyperglycemia, and decreased mental status. In addition, there have been literature reports of non-cardiogenic pulmonary edema in patients taking large overdoses of verapamil (up to approximately 9g). In acute overdosage, gastrointestinal decontamination with cathartics and whole bowel irrigation should be considered. Calcium, inotropes (i.e., isoproterenol, dopamine, and glucagon), atropine, vasopressors (i.e., norepinephrine, and epinephrine), and cardiac pacing have been used with variable results to reverse hypotension and myocardial depression. In a few reported cases, overdose with calcium channel blockers that was initially refractory to atropine became more responsive to this treatment when the patients received large doses (close to 1g/hour for more than 24 hours) of calcium chloride. Calcium chloride is preferred to calcium gluconate since it provides 3 times more calcium per volume. Asystole should be handled by the usual measures including cardiopulmonary resuscitation. Verapamil cannot be removed by…

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Effects of other drugs on verapamil pharmacokinetics In vitro metabolic studies indicate that verapamil is metabolized by cytochrome P450, CYP3A4, CYP1A2, and CYP2C. Clinically significant interactions have been reported with inhibitors of CYP3A4 (e.g., erythromycin, ritonavir) causing elevation of plasma levels of verapamil while inducers of CYP3A4 (e.g., rifampin) have caused a lowering of plasma levels of verapamil. Hypotension, bradyarrhythmias, and lactic acidosis have been observed in patients receiving concurrent telithromycin, an antibiotic in the ketolide class of antibiotics. Ivabradine Concurrent use of verapamil increases exposure to ivabradine and may exacerbate bradycardia and conduction disturbances. Avoid concomitant use of ivabradine and verapamil. HMG-CoA Reductase Inhibitors The use of HMG-CoA reductase inhibitors that are CYP3A4 substrates in combination with verapamil has been associated with reports of myopathy/rhabdomyolysis. Co-administration of multiple doses of 10 mg of verapamil with 80 mg simvastatin resulted in exposure to simvastatin 2.5-fold that following simvastatin alone. Limit the dose of simvastatin in patients on verapamil to 10 mg daily. Limit the daily dose of lovastatin to 40 mg. Lower starting and maintenance doses of other CYP3A4 substrates (e.g., atorvastatin) may be required as verapamil may increase the plasma concentration of these drugs. Beta Blockers Concomitant therapy with beta-adrenergic blockers and verapamil may result in additive negative effects on heart rate, atrioventricular conduction, and/or cardiac contractility. The combination of sustained-release verapamil and beta-adrenergic blocking agents has not been studied. However, there have been reports of excess bradycardia and AV block, including complete heart block, when the combination has been used for the treatment of hypertension. For hypertensive patients, the risk of combined therapy may outweigh the potential benefits. The combination should be used only with caution and close monitoring. Asymptomatic bradycardia (36 beats/min) with a wandering atrial pacemaker has been observed in a patient receiving concomitant timolol (a beta-adrenergic blocker) eyedrops and oral verapamil. A decrease in metoprolol clearance has been reported when verapamil and metoprolol were administered together. A similar effect has not been observed when verapamil and atenolol are given together. Clonidine Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with verapamil. Monitor heart rate in patients receiving concomitant verapamil and clonidine. Digitalis Consider reducing digoxin dose when verapamil and digoxin are to be given together. Monitor digoxin level periodically during therapy. Chronic verapamil treatment can increase serum digoxin levels by 50% to 75% during the first week of therapy, and this can result in digitalis toxicity. In patients with hepatic cirrhosis the influence of verapamil on digoxin pharmacokinetics is magnified. Verapamil may reduce total body clearance and extrarenal clearance of digoxin by 27% and 29%, respectively. If digoxin toxicity is suspected, suspend or discontinue digoxin therapy. In previous clinical trials with other verapamil formulations related to the control of ventricular response in patients taking digoxin who had atrial fibrillation or atrial flutter, ventricular rates below 50/min at rest occurred in 15% of patients, and asymptomatic hypotension occurred in 5% of patients. Antihypertensive Agents Verapamil administered concomitantly with oral antihypertensive agents (e.g., vasodilators, angiotensin-converting enzyme inhibitors, diuretics, beta blockers) will usually have an additive effect on lowering blood pressure. Patients receiving these combinations should be appropriately monitored. Concomitant use of agents that attenuate alpha-adrenergic function with verapamil may result in reduction in blood pressure that is excessive in some patients. Such an effect was observed in one study following the concomitant administration of verapamil and prazosin. Antiarrhythmic Agents Disopyramide: Until data on possible interactions between verapamil and disopyramide phosphate are obtained, disopyramide should not be administered within 48 hours before or 24 hours after verapamil administration. Flecainide: A study in healthy volunteers showed that the concomitant administration of flecainide and verapamil may have additive effects on myocardial contractility, AV conduction, and repolarization. Concomitant therapy with flecainide and verapamil may result in additive negative inotropic effect and prolongation of atrioventricular conduction. Quinidine: In a small number of patients with hypertrophic cardiomyopathy (IHSS), concomitant use of verapamil and quinidine resulted in significant hypotension. Until further data are obtained, combined therapy of verapamil and quinidine in patients with hypertrophic cardiomyopathy should probably be avoided. The electrophysiological effects of quinidine and verapamil on AV conduction were studied in 8 patients. Verapamil significantly counteracted the effects of quinidine on AV conduction. There has been a report of increased quinidine levels during verapamil therapy. Nitrates: Verapamil has been given concomitantly with short- and long-acting nitrates without any undesirable drug interactions. The pharmacologic profile of both drugs and the clinical experience suggest beneficial interactions. Alcohol: Verapamil has been found to significantly inhibit ethanol elimination resulting in elevated blood ethanol concentrations that may prolong the intoxicating effects of alcohol. (See CLINICAL PHARMACOLOGY - Pharmacokinetics and Metabolism. )