Calcium channel blockers in angina

There are three different groups of calcium channel blockers:

• Dihydropyridine group e.g. nifedipine, amlodipine, felodipine. This group acts primarily as arterial vasodilators. They are effective in the management of angina. However, side-effects such as flushing and tachycardia may be troublesome - particularly with short-acting preparations. There is some observational evidence that the use of high doses or short-acting dihydropyridines may be associated with adverse morbidity and mortality. Although the evidence currently available falls short of proof, it appears prudent to use longer-acting agents.
• Phenylalkylamine CCBs e.g. verapamil. These act primarily to reduce the force of myocardial contraction and to limit heart rate. They are contraindicated in patients with ventricular impairment. Extreme caution is required if combining verapamil with a beta-blocker - in general, this combination should be avoided.
• Benzothiazepine CCBs (diltiazem). This has properties intermediate between verapamil and the dihydropyridines. Because of the risk of bradycardia, it should be used with caution in association with beta-blockers.

Reference:

1. British National Formulary (BNF); NICE Evidence Services (UK access only). Calcium channel blockers.