Verapamil Hydrochloride

Generic Name: verapamil hydrochloride

Over-the-Counter (OTC)

Brand Names:

Verapamil Hydrochloride

DESCRIPTION Verapamil hydrochloride (verapamil HCl) tablets, USP is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) available for oral administration in film-coated tablets containing 40 mg, 80 mg or 120 mg of verapamil hydrochloride. The structural formula of verapamil HCl is: C 27 H 38 N 2 O 4 • HCl M.W.

Overview

DESCRIPTION Verapamil hydrochloride (verapamil HCl) tablets, USP is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) available for oral administration in film-coated tablets containing 40 mg, 80 mg or 120 mg of verapamil hydrochloride. The structural formula of verapamil HCl is: C 27 H 38 N 2 O 4 • HCl M.W.

Uses

INDICATIONS AND USAGE Verapamil hydrochloride tablets USP are indicated for the treatment of the following: Angina 1.Angina at rest including: -Vasospastic (Prinzmetal's variant) angina -Unstable (crescendo, pre-infarction) angina 2.Chronic stable angina (classic effort-associated angina) Arrhythmias 1.In association with digitalis for the control of ventricular rate at rest and during stress in patients with chronic atrial flutter and/or atrial fibrillation (see WARNINGS: Accessory bypass tract ) 2.Prophylaxis of repetitive paroxysmal supraventricular tachycardia Essential hypertension Verapamil hydrochloride is indicated for the treatment of hypertension, to lower blood pressure.

Dosage

DOSAGE AND ADMINISTRATION The dose of verapamil must be individualized by titration. The usefulness and safety of dosages exceeding 480 mg/day have not been established; therefore, this daily dosage should not be exceeded. Since the half-life of verapamil increases during chronic dosing, maximum response may be delayed. Angina: Clinical trials show that the usual dose is 80 mg to 120 mg three times a day. However, 40 mg three times a day may be warranted in patients who may have an increased response to verapamil (e.g., decreased hepatic function, elderly, etc). Upward titration should be based on therapeutic efficacy and safety evaluated approximately eight hours after dosing.

Side Effects

ADVERSE REACTIONS Serious adverse reactions are uncommon when verapamil hydrochloride 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.

Interactions

Drug Interactions Cytochrome inducers/inhibitors: In vitro metabolic studies indicate that verapamil is metabolized by cytochrome P450 CYP3A4, CYP1A2, CYP2C8, CYP2C9 and CYP2C18. 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. 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.

Warnings

WARNINGS Heart failure: Verapamil has a negative inotropic effect, which in most patients is compensated by its afterload reduction (decreased systemic vascular resistance) properties without a net impairment of ventricular performance. In clinical experience with 4,954 patients, 87 (1.8%) developed congestive heart failure or pulmonary edema. Verapamil should be avoided in patients with severe left ventricular dysfunction (e.g., ejection fraction less than 30%) or moderate to severe symptoms of cardiac failure and in patients with any degree of ventricular dysfunction if they are receiving a beta-adrenergic blocker (see PRECAUTIONS, Drug interactions ). CONTRAINDICATIONS Verapamil HCl tablets are contraindicated in: 1.Severe left ventricular dysfunction (see WARNINGS ) 2.Hypotension (systolic pressure less than 90 mm Hg) or cardiogenic shock 3.Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker) 4.Second-or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker) 5.Pati...

Pregnancy

Pregnancy Pregnancy Category C. Reproduction studies have been performed in rabbits and rats at oral doses up to 1.5 (15 mg/kg/day) and 6 (60 mg/kg/day) times the human oral daily dose, respectively, and have revealed no evidence of teratogenicity. In the rat, however, this multiple of the human dose was embryocidal and retarded fetal growth and development, probably because of adverse maternal effects reflected in reduced weight gains of the dams. This oral dose has also been shown to cause hypotension in rats. There are no adequate and well-controlled studies in pregnant women.

Storage

HOW SUPPLIED Verapamil Hydrochloride Tablets, USP 120 mg tablets are round, standard concave, white film-coated, scored, debossed "HP" above and "27" below on one side and plain on the reverse side, supplied as: 42291-855-01 bottle of 100 Verapamil Hydrochloride Tablets, USP 80 mg tablets are round, standard concave, white film-coated, scored, debossed "HP" above and "26" below on one side and pla...

Frequently Asked Questions

What is Verapamil Hydrochloride used for?

INDICATIONS AND USAGE Verapamil hydrochloride tablets USP are indicated for the treatment of the following: Angina 1.Angina at rest including: -Vasospastic (Prinzmetal's variant) angina -Unstable (crescendo, pre-infarction) angina 2.Chronic stable angina (classic effort-associated angina) Arrhythmias 1.In association with digitalis for the control of ventricular rate at rest and during stress in patients with chronic atrial flutter and/or atrial fibrillation (see WARNINGS: Accessory bypass tract ) 2.Prophylaxis of repetitive paroxysmal supraventricular tachycardia Essential hypertension Verapamil hydrochloride is indicated for the treatment of hypertension, to lower blood pressure.

What are the side effects of Verapamil Hydrochloride?

ADVERSE REACTIONS Serious adverse reactions are uncommon when verapamil hydrochloride 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.

Can I take Verapamil Hydrochloride during pregnancy?

Pregnancy Pregnancy Category C. Reproduction studies have been performed in rabbits and rats at oral doses up to 1.5 (15 mg/kg/day) and 6 (60 mg/kg/day) times the human oral daily dose, respectively, and have revealed no evidence of teratogenicity. In the rat, however, this multiple of the human dose was embryocidal and retarded fetal growth and development, probably because of adverse maternal effects reflected in reduced weight gains of the dams. This oral dose has also been shown to cause hypotension in rats. There are no adequate and well-controlled studies in pregnant women.

What are the important warnings for Verapamil Hydrochloride?

WARNINGS Heart failure: Verapamil has a negative inotropic effect, which in most patients is compensated by its afterload reduction (decreased systemic vascular resistance) properties without a net impairment of ventricular performance. In clinical experience with 4,954 patients, 87 (1.8%) developed congestive heart failure or pulmonary edema. Verapamil should be avoided in patients with severe left ventricular dysfunction (e.g., ejection fraction less than 30%) or moderate to severe symptoms of cardiac failure and in patients with any degree of ventricular dysfunction if they are receiving a beta-adrenergic blocker (see PRECAUTIONS, Drug interactions ). CONTRAINDICATIONS Verapamil HCl tablets are contraindicated in: 1.Severe left ventricular dysfunction (see WARNINGS ) 2.Hypotension (systolic pressure less than 90 mm Hg) or cardiogenic shock 3.Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker) 4.Second-or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker) 5.Pati...

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.