From the Guidelines
Verapamil should be used with caution in patients with heart failure, liver disease, or kidney problems, and the typical starting dose for adults with hypertension is 80 mg three times daily, which can be increased gradually to a maximum of 480 mg daily. The medication works by blocking calcium channels in heart muscle and blood vessel walls, which relaxes blood vessels, reduces heart workload, and improves blood flow 1. Common side effects include constipation, dizziness, headache, and ankle swelling. Patients should avoid grapefruit products while taking verapamil as they can increase blood levels of the medication. Some key points to consider when using verapamil include:
- The medication can be used to control ongoing or recurring ischemia-related symptoms in patients who already are receiving adequate doses of nitrates and beta blockers 1.
- Verapamil and diltiazem should be avoided in patients with pulmonary edema or evidence of severe LV dysfunction 1.
- The CCB evidence base in UA/NSTEMI is greatest for verapamil and diltiazem 1.
- Verapamil has been found to have favorable effects on symptoms, probably by virtue of improving ventricular relaxation and filling as well as relieving myocardial ischemia and decreasing LV contractility 1.
- The medication can occasionally harbor a potential for clinically important adverse consequences, including death in a few HCM patients with severe disabling symptoms and markedly elevated pulmonary arterial pressure in combination with marked outflow obstruction 1. It's essential to take verapamil regularly as prescribed and not stop suddenly without consulting a healthcare provider, as this could worsen underlying conditions. Additionally, verapamil may be used to control the rate of ventricular response in patients with atrial fibrillation, and it has been associated with an improvement in quality of life and exercise tolerance 1. However, the medication should be used cautiously or avoided in patients with HF due to systolic dysfunction because of its negative inotropic effects 1. Overall, verapamil is a valuable medication for treating various cardiovascular conditions, but it requires careful consideration of the patient's individual needs and health status.
From the FDA Drug Label
Verapamil hydrochloride is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) that exerts its pharmacologic effects by modulating the influx of ionic calcium across the cell membrane of the arterial smooth muscle as well as in conductile and contractile myocardial cells Verapamil hydrochloride dilates the main coronary arteries and coronary arterioles, both in normal and ischemic regions, and is a potent inhibitor of coronary artery spasm, whether spontaneous or ergonovine-induced Verapamil hydrochloride regularly reduces the total systemic resistance (afterload) against which the heart works both at rest and at a given level of exercise by dilating peripheral arterioles.
- Main uses of Verapamil:
- Treatment of essential hypertension
- Relief of vasospastic angina
- Management of unstable angina and classical effort angina
- Control of ventricular rate in patients with atrial fibrillation or atrial flutter
- Key pharmacological effects:
From the Research
Verapamil Overview
- Verapamil is a phenylalkylamine derivative that antagonizes calcium influx through the slow channels of vascular smooth muscle and cardiac cell membranes 3.
- It is used to treat various cardiovascular conditions, including hypertension, angina, cardiac arrhythmias, and cardiomyopathies 3, 4.
Therapeutic Uses
- Verapamil is effective in managing essential hypertension, particularly in patients with mild to moderate hypertension 3.
- It is also used to treat supraventricular tachyarrhythmias, including paroxysmal supraventricular tachycardia and atrial flutter/fibrillation 4, 5.
- Verapamil has been shown to be effective in preventing and treating cardio-renal syndromes in diabetic hypertensive patients 6.
Pharmacological Properties
- Verapamil inhibits the slow inward channel in the heart and blocks calcium influx in smooth muscle 4.
- It has a mild, noncompetitive sympathetic antagonist effect and depresses AV nodal conduction 4.
- Verapamil causes coronary and peripheral vasodilation and depresses myocardial contractility and electrical activity in the atrioventricular and sinoatrial nodes 3.