Belonging to the medicinal group called benzothiazepines, Diltiazem is a drug commonly used to treat conditions like angina pectoris, hypertension and even arrhythmia. Its ability as a vasodilator helps facilitate enhanced blood flow thereby preventing heart failures.

Common trade names

The active pharmaceutical ingredients of Diltiazem are typically marketed under a variety of brand names. Some of the more common ones include Herben, Cartia XT, Cardizem, Tiazac, Tiamate, Tiazac XC, Tildiem (used in Europe predominantly), Viazem, Adizem, Dilatam, Angiozem, Dilzem, Dilcardia, Diltime, Diltelan, Dyalec, Tildiem, Filazem, Vasmulax, Zemtrial, Zandil, Dilcontin SR (used in India predominantly.) In the latter, SR stands for sustained release.

Pharmacological effects

Diltiazem works by dilating blood vessels, thereby facilitating increased blood flow. This helps to reduce afterload on the blood vessels as well as peripheral resistance to the blood flowing through the vessels. The drug has a slight amount of negative inotropic side effect. This means that Diltiazem can cause reduced contractions in the heart and reduction in the overall oxygen consumption levels in the body. Apart from this, Diltiazem also causes a little bit of chronotropic effect.

This lowers the average heart rate in the body because the SA node slows down dramatically. The overall rate of oxygen consumption in the myocardium also goes down significantly. The drug Diltiazem also results in a little amount of dromotropic effects. Since the conduction via SA nodes is reduced or slowed down, every heartbeat requires more time. This also reduces oxygen consumption inside the myocardium.

Toxicity and other effects

In addition to the above-mentioned side effects, Diltiazem can also cause reflex sympathetic responses inside the body. This is because the peripheral dilation of the blood vessels is increased, which results in reduced blood pressure in the body. The reflex response works by counteracting the dromotropic, inotropic as well as chronotropic side effects caused by the active pharmaceutical ingredients.

Precautions to observe

Patients taking Diltiazem need to observe certain precautions. If patients have a reduced amount of ventricular functionality then their bodies may not be able to sustain chronotropic or inotropic side effects produced by Diltiazem. If patients have AV or SA node abnormalities or imbalances then too usage of Diltiazem should be prohibited. Patients with low levels of blood pressure are also advised against consumption of Diltiazem because systolic BP below 80 mm per Hg warrants staying away from Diltiazem.

In addition, if a patient has a condition of Wolff-Parkinson-White Syndrome, the usage of Diltiazem can enhance ventricular rates. Such patients are also prohibited from consuming these active pharmaceutical ingredients.

Reactions with other drugs

If an existing beta blocking agent is being used in a patient then Diltiazem should not be administered intravenously. It can cause an AV node blockage. If Quinidine is being administered to the patient then too Diltiazem should not be prescribed. Both drugs have reduced clearance at both AV and SA nodes. Both the drugs Diltiazem as well as Verapamil reduce presence of hepatic cytochromes. This can result in a drug reaction between the two.