Hydroquinidine

Hydroquinidine is a quinidine derivative used as an antiarrhythmic agent. It is classified under the Vaughan Williams classification of antiarrhythmic drugs, specifically as a Class Ia antiarrhythmic.

Pharmacology

Hydroquinidine works by blocking the fast inward sodium channel, which slows the rate of rise of the action potential, thus prolonging the refractory period. This action can help to prevent arrhythmias by reducing the likelihood of abnormal electrical activity in the heart.

Medical Uses

Hydroquinidine is primarily used in the treatment of ventricular arrhythmias, including ventricular tachycardia and ventricular fibrillation. It may also be used in the treatment of atrial fibrillation and atrial flutter.

Side Effects

Common side effects of hydroquinidine include nausea, vomiting, diarrhea, and abdominal pain. More serious side effects can include cardiotoxicity, cinchonism, and thrombocytopenia.

Contraindications

Hydroquinidine is contraindicated in patients with hypersensitivity to quinidine or other quinoline derivatives, as well as in patients with severe heart failure, AV block, or a history of torsades de pointes.

Interactions

Hydroquinidine can interact with other medications, including digoxin, warfarin, and certain antibiotics. It is important for patients to inform their healthcare provider of all medications they are currently taking.

See Also

• Quinidine
• Antiarrhythmic agent
• Ventricular arrhythmia
• Atrial fibrillation