Diltiazem is a non-dihydropyridine (non-DHP) member of the class of drugs known as calcium channel blocker

Calcium channel blocker

A calcium channel blocker is a chemical that disrupts the movement of calcium through calcium channels.CCB drugs devised to target neurons are used as antiepileptics. However, the most widespread clinical usage of calcium channel blockers is to decrease blood pressure in patients with...

s, used in the treatment of hypertension

Hypertension

Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

, angina pectoris, and some types of arrhythmia.

It is also an effective preventive medication for migraine

Migraine

Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...

. It is a class 3 anti-anginal drug, and a class IV antiarrhythmic. It is a common adulterant of cocaine seized in the UK, and has been found to reduce cocaine cravings in rats, indicating that it may prolong the "high" (see below).