Disopyramide Topic Review

Disopyramide is a class IA antiarrhythmic drug which acts via blockade of sodium channels depressing phase 0 of the action potential. 

Disopyramide possesses significant negative inotropic and anticholinergic effects and enhances atrioventricular (AV) nodal conduction.

Indications

Disopyramide is used to maintain sinus rhythm in patients with atrial fibrillation (AF). Due to potential adverse effects and the availability of other drugs, disopyramide is rarely used for this purpose. Vagally mediated atrial fibrillation responds well to disopyramide. Disopyramide is not mentioned in the 2023 American College of Cardiology/American Heart Association/American College of Clinical Pharmacy Guideline/Heart Rhythm Society for the Diagnosis and Management of Atrial Fibrillation. 

Disopyramide is the historical treatment for hypertrophic obstructive cardiomyopathy due to the significant negative inotropic effects. It is currently recommended only for persistent symptoms if non-dihydropyridine calcium channel blockers and beta-blockers fail. Patients on disopyramide should also take one of the above concomitantly since disopyramide enhances AV nodal conduction causing rapid conduction should AF or atrial flutter develop.

Disopyramide can be used for the treatment of ventricular arrhythmias, although is rarely utilized for this indication.

Adverse Effects

Adverse effects associated with disopyramide may include:

• anticholinergic side effects including xerostomia (dry mouth), urinary retention, visual disturbances and decreased perspiration;
• prolongation of the QT interval resulting in polymorphic ventricular tachycardia; and/or
• fatigue, hypotension, dizziness and weakness.

Additional information

AF triggered by situations of vagal stimulation has been well described (nausea, vomiting, abdominal pain, severe coughing, young healthy athletes with high vagal tone, etc.). In this scenario, the historical antiarrhythmic drug which has been successful is disopyramide. The significant anticholinergic activity making it more effective in this situation.

Reference:

• Sundjaja JH, et al. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK557434/#:~:text=Disopyramide%20is%20a%20medication%20used,atrial%20fibrillation%20and%20hypertrophic%20cardiomyopathy. Updated May 22, 2023. Accessed May 1, 2024.