Diltiazem hydrochloride is a medication used for treating high blood pressure or chest pain known as angina. It is a calcium channel blocker that is also used to effectively treat migraines. Diltiazem is an inhibitor of the CYP3A4 enzyme and is also a potent vasodilator, increasing blood flow whilst decreasing blood pressure.
Diltiazem is part of the benzothiazepine class of calcium channel blockers used in the treatment of hypertension, angina pectoris and superventricular tachyarrhythmias. Like various other calcium channel blockers, diltiazem works by inhibiting the transmembrance influx of calcium ions into muscle cells. This inhibition results in arterial vasodilation and decreases oxygen use in the myocardium.
Several million prescriptions for diltiazem are written each year. It is currently available orally under numerous generic formulations as well as commercial brand names such as Cardizem and Tiazac. Extended release formulations are too availalble and are widely used. These come under the names Cardizem CD, Cadizem LA, Cartia XT, Dilacor XR, Dilt-XR, Diltia XT and Taztia XT. Dosages vary from 60 to 420mg daily.
Recent studies have demonstrated that diltiazem is able to reduce cocaine cravings in drug-addicted rats. It is thought it works by affecting dopaminergic and gluatmatergic signaling in the brain. Diltiazem has also shown to enhance the pain relieving effects of morphine in animal tests.
Research regarding the use of diltiazem for prophylaxis of cluster migraines is ongoing as it has shown some efficacy. Currently doctors in the US prescribe it off-label for such use.
As well as the aforementioned conditions, Diltiazem is also used in the treatment of anal fissures. If taken topically in a cream it has shown increased effectiveness. Like all non-surgical treatments of anal fissure it has demonstrated good overall short-term efficacy.
Diltiazem should be taken with caution by patients with liver and/or kidney impairment, ventricular dysfunction, congestive heart failure, sinoatrial nodal dysfunction and severe bradycardia. Cirrhosis patients ought to consider decreasing the dosage of calcium channel blockers. Diltiazem should also not be used in those with acute myocardial infarction. Since it is classified as pregnancy category C, it should be taken with caution during pregnancy and only when the benefits outweight the potential risk to the fetus.