Bretylium

Bretylium is a drug that was primarily used as an antiarrhythmic agent to treat ventricular fibrillation and ventricular tachycardia. It is a class III antiarrhythmic drug, which means it works by blocking potassium channels and thus prolonging the action potential duration and refractory period.

Mechanism of Action

Bretylium works by blocking the release of norepinephrine from the sympathetic nervous system's nerve endings. This action can help to stabilize the heart rhythm and prevent the occurrence of life-threatening arrhythmias. It also has a direct action on the heart muscle cells (myocytes), where it blocks potassium channels, leading to a prolongation of the action potential duration and refractory period.

Uses

Bretylium was primarily used to treat life-threatening ventricular arrhythmias, such as ventricular fibrillation and ventricular tachycardia. However, it is no longer commonly used due to the availability of more effective and safer alternatives.

Side Effects

The most common side effects of bretylium include nausea, vomiting, hypotension (low blood pressure), and dyspnea (difficulty breathing). In rare cases, it can cause more serious side effects such as pulmonary edema (fluid accumulation in the lungs) and hypertension (high blood pressure).

History

Bretylium was first synthesized in the 1950s and was initially used as an antihypertensive agent. However, it was later found to be effective in treating ventricular arrhythmias and was widely used for this purpose until the 1990s, when newer and safer drugs became available.

See Also

• Antiarrhythmic agent
• Ventricular fibrillation
• Ventricular tachycardia