Calcium channel blockers to prevent angina
Nondihydropyridine calcium channel blockers (diltiazem, verapamil) reduce heart rate and can be used as an alternative if beta-blocker therapy is contraindicated or not tolerated. There is some evidence that they are of benefit following myocardial infarction in patients without heart failure. Do not use diltiazem or verapamil in combination with a beta blocker without specialist advice because of the risk of severe bradycardia and heart failure. To prevent symptoms of angina, use:
1diltiazem modified-release 180 mg orally, daily, increasing if required up to 360 mg daily diltiazem diltiazem diltiazem
OR
1verapamil modified-release 120 mg orally, daily, increasing if required up to 480 mg daily. verapamil verapamil verapamil
Avoid using diltiazem or verapamil for patients with left ventricular dysfunction (left ventricular ejection fraction 40% or less).
A dihydropyridine calcium channel blocker (amlodipine, modified-release nifedipine) can be added to a beta blocker if angina persists. Add:
1amlodipine 2.5 mg orally, daily, increasing if required up to 10 mg daily amlodipine amlodipine amlodipine
OR
1nifedipine modified-release 30 mg orally, daily, increasing if required up to 90 mg daily. nifedipine nifedipine nifedipine
Dihydropyridine calcium channel blockers can be used alone for angina, but caution is needed because sympathetic tone and heart rate can increase (secondary to arteriolar dilation).