| Noun | 1. | Calan - a drug (trade names Calan and Isoptin) used as an oral or parenteral calcium blocker in cases of hypertension or congestive heart failure or angina or migrainecalcium blocker, calcium-channel blocker - any of a class of drugs that block the flow of the electrolyte calcium (either in nerve cell conduction or smooth muscle contraction of the heart); has been used in the treatment of angina or arrhythmia or hypertension or migraine | |