| Indication | For the treatment of Hypertension |
| Pharmacodynamics | Diltiazem, a benzothiazepine calcium-channel blocker, is used alone or with an angiotensin-converting enzyme inhibitor, to treat hypertension, chronic stable angina pectoris, and Prinzmetal's variant angina. Diltiazem is a non-dihydropyridine (DHP)member of the calcium channel blocker class, along with Verapamil. Diltiazem is similar to other peripheral vasodilators. Diltiazem inhibits the influx of extra cellular calcium across the myocardial and vascular smooth muscle cell membranes possibly by deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum. The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload. |
| Mechanism of action | Possibly by deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum, diltiazem, like verapamil, inhibits the influx of extracellular calcium across both the myocardial and vascular smooth muscle cell membranes. The resultant inhibition of the contractile processes of the myocardial smooth muscle cells leads to dilation of the coronary and systemic arteries and improved oxygen delivery to the myocardial tissue. |
| Absorption | Diltiazem is well absorbed from the gastrointestinal tract but undergoes substantial hepatic first-pass effect. |
| Volume of distribution | Not Available |
| Protein binding | 70%-80% |
| Metabolism | Diltiazem is metabolized by and acts as an inhibitor of the CYP3A4 enzyme. |
| Route of elimination | Not Available |
| Half life | 3.0 - 4.5 hours |
| Clearance | Not Available |
| Toxicity | LD50=740mg/kg (orally in mice) |