Calan SR is made by Pfizer, Inc.
Generic Calan SR is made by various manufacturers.
Calan SR is part of a class of drugs called
calcium channel blockers. Calan SR helps to slow down the rate at which calcium moves into your heart and blood vessel walls. This, in turn, helps to relax the blood vessels, which improves blood flow and makes it easier for the heart to pump blood.
There are two basic types of calcium channel blockers, dihydropyridine and non-dihydropyridine. The most important difference between the two types is that non-dihydropyridine calcium channel blockers can slow down the heart rate, while dihydropyridine calcium channel blockers do not. Calan SR is a non-dihydropyridine calcium channel blocker, which means that it can decrease the heart rate. As a result, Calan SR is useful for treating certain types of irregular heart rhythms (arrhythmias).