Diltiazem

As Diltiazem is called a certain calcium channel blocker. The drug is used to treat cardiovascular diseases.

What is diltiazem?

Diltiazem is an antiarrhythmic that is one of the calcium antagonists or calcium channel blockers. The active ingredient has vasodilating properties and slows down the performance of the heart's AV node. Furthermore, diltiazem belongs to the benzothiazepines.

Diltiazem was approved in Europe in the early 1980s. The product is primarily used against cardiovascular diseases and is offered by the pharmaceutical company Pfizer in Germany under the name Dilzem®. In addition, various other suppliers sell the drug as a generic.

Pharmacological effect

Diltiazem is a calcium channel blocker. The active ingredient is able to combine all three active properties of calcium channel blockers. First of all, the heart's need for oxygen is reduced and the blood flow to the heart muscle is increased. This has the advantage that angina pectoris attacks can be reduced or even completely prevented. At the same time, Diltiazem unfolds its effect on the blood vessels by expanding them. This lowers high blood pressure.

Diltiazem has another positive effect on the heart muscle, making the drug suitable for treating cardiac arrhythmias. When administered in medically appropriate doses, the agent works to slow the heart rate. In this way, there is a delay in the transmission of excitation between the chambers of the heart and the auricle, which in turn results in a significant reduction in the load on the heart.

As a calcium channel blocker, diltiazem blocks special channels within the muscle cell walls that allow calcium to flow into the cells. The calcium inside the cells tenses the muscle cells, which leads to the narrowing of the blood vessels. However, due to the effect of diltiazem, the muscle cells can relax and the vessels expand (vasodilatation).

The bioavailability of the calcium channel blocker is around 40 percent. The drug is metabolized by the liver. The mean plasma half-life is given as four hours. The breakdown of diltiazem from the body occurs through urine and stool.

Medical application & use

Diltiazem is administered against high blood pressure that has no organic causes. Another important indication is heart disease, which is associated with a problematic oxygen supply to the heart muscle, as well as circulatory disorders in the coronary vessels. This is the case with coronary artery disease (CHD). Diltiazem is used to treat stable, unstable and vasospastic angina pectoris.

As an antiarrhythmic, diltiazem can also be used against cardiac arrhythmias. The drug is suitable for the prevention of paroxysmal supraventricular tachycardia. In the case of atrial flutter and atrial fibrillation, the active ingredient can slow down the pulse rate.

Occasionally, diltiazem is used following a kidney transplant to counter the rejection of the transplanted organ. It can also reduce the toxicity of ciclosporin A during immunosuppressive treatment.

Diltiazem can also be administered externally. The active ingredient is used in the form of a cream or ointment for treating anal fissures. The medicament is also suitable for the treatment of diffuse esophageal spasms in order to bring about relaxation of the esophageal muscles.

Diltiazem is mostly taken as a prolonged-release tablet that continuously releases the active ingredient. For the treatment of high blood pressure and coronary artery disease, one tablet is given twice a day. If necessary, the dose can be increased to four prolonged-release tablets per day. Since the taking of diltiazem is a long-term therapy, the active ingredient is usually taken permanently.

Risks & side effects

Taking diltiazem can cause side effects in some patients. These are mostly tiredness, headache, dizziness, muscle pain, general weakness, edema of the ankles or legs, joint pain and allergic reactions such as rashes and itching. Swelling of the lymph nodes, autoimmune diseases such as lupus erythematosus, growths on the gums and an increase in white blood cells are rare.

If the dosage is too high, there is a risk of cardiac conduction disorders, a sharp drop in blood pressure, bradycardias, palpitations, heart muscle weakness, erectile dysfunction in men and fainting if the heart has been damaged.

If there is hypersensitivity to diltiazem, the affected person must refrain from taking the calcium channel blocker. The same applies in the case of cardiac muscle weakness, sinus node syndrome (stimulus conduction disorder to the heart), acute heart attack, shock and certain cardiac arrhythmias with a high heartbeat frequency. Diltiazem should only be dosed carefully in the event of ventricular tachycardia or impaired liver function.

The calcium channel blocker should not be administered during pregnancy and breastfeeding. Women of childbearing potential must rule out pregnancy before starting diltiazem therapy. The drug must not be used in children either, as insufficient knowledge is available about the effects of the drug on them.

Interactions should also be considered when taking other drugs at the same time. For example, the administration of inhalation anesthetics can lead to cardiac arrest due to AV blockage and an increased blood pressure lowering effect.

The effect of diltiazem can be enhanced by combining it with antiarrhythmics such as quinidine or beta blockers. The effect of the agent is reduced by the simultaneous administration of enzyme inducers. These include a. Phenytoin, phenobarbital, and rifampicin. Diltiazem, in turn, can reduce the effects of lithium.

Alkaline infusion and injection solutions are considered incompatible with diltiazem, so that they must not be mixed with the calcium channel blocker. Otherwise there is a risk of flocculation with diltiazem within the solution.