Rythmol (generic: propafenone) is a prescription medication used to treat irregular heartbeat (known medically as arrhythmia). This medication belongs to a group of drugs called Class IC antiarrhythmics which work by blocking sodium channels in the heart, slowing down electrical signals to stabilize heart rhythm.

Rythmol comes in regular tablet and extended-release capsule (Rythmol SR) forms. The tablet is usually taken 3 times daily, every 8 hours. The extended-release capsule is usually taken twice daily, once every 12 hours.

Common side effects include nausea, vomiting, and unusual taste. Rythmol can cause dizziness. Do not drive or operate heavy machinery until you know how it affects you.