This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To determine the effect of long‐term treatment with antiarrhythmic drugs in patients who have recovered sinus rhythm after having atrial fibrillation, to reduce death, stroke and embolism, drug adverse effects and recurrence of atrial fibrillation.

Primary aim is to assess the effects of any antiarrhythmic drugs compared with no antiarrhythmic drugs treatment, no treatment, placebo, or treatment for rate control. If several antiarrhythmic drugs appear to be effective the secondary aim will be to assess which is more effective.