Generic name: Propafenone.

Rythmol is an anti-arrhythmic. It alters nerve impulses within the heart to regulate heartbeat. 

Quick Facts About Rythmol


Used to correct heartbeat irregularities, including ventricular arrhythmias.

Rythmol Dosage

May take with or without food. Take exactly as prescribed, maintaining a constant level in the blood.

  • Usual adult dose: 150 milligrams every 8 hours, up to 900 milligrams per day maximum. Treatment usually begins in the hospital. Now comes in tablet.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless almost time for next dose or more than 4 hours past missed dose. Otherwise, do not take missed dose; go back to regular schedule. Do not double doses.

Rythmol Side Effects

Overdose symptoms:

convulsions (rarely), heartbeat irregularities, sleepiness. Symptoms are worse in the first 3 hours of taking medication. If you suspect an overdose, immediately seek medical attention.

More common side effects: constipation, dizziness, heartbeat abnormalities, nausea, unusual taste in the mouth, vomiting.

Other Rythmol side effects: abdominal pain or cramps; anemia; angina (crushing chest pain); anxiety; blood disorders; blurred vision; breathing difficulties; bruising; cardiac arrest; coma; confusion; congestive heart failure; depression; diarrhea; dreaming abnormalities; drowsiness; dry mouth; eye irritation; fainting or near fainting; fatigue; fever; flushing; gas; hair loss; headache; heart palpitations; heartbeat abnormalities (rapid, irregular, slow); hot flashes; impotence; increased blood sugar; indigestion; inflamed esophagus, stomach, or intestines; insomnia; itching; joint pain; kidney disease; kidney failure; lack of coordination; liver dysfunction; loss of appetite; loss of balance; low blood pressure; memory loss; muscle cramps; muscle weakness; numbness; pain; psychosis; rash; red or purple skin spots; ringing in the ears; seizures; speech abnormalities; sweating; swelling due to fluid retention; tingling or pins and needles; tremor; unusual smell sensations; vertigo: vision abnormalities; weakness.


Inform your doctor before combining Rythmol with:

beta-blockers such as Inderal and Lopressor; Cimetidine (Tagamet); digitalis (Lanoxin); local anesthetics such as Novocaine; quinidine (Cardioquin); warfarin (Coumadin).

No known food/other substance interactions. 

Special Cautions

May cause birth defects. If pregnant or planning to become pregnant, inform your doctor immediately. Should not take if breastfeeding.

No special precautions apply to seniors.

Not generally prescribed for children.

  • Do not take if sensitive to or allergic to Rythmol.
  • Doctor will not prescribe Rythmol if you have: abnormally slow heartbeat; certain heartbeat irregularities such as atrioventricular block or “sick sinus’ syndrome not corrected by a pacemaker; cardiogenic shock; chronic bronchitis or emphysema; congestive heart failure; mineral (electrolyte) imbalance: severe low blood pressure.
  • If you have a pacemaker, doctor must monitor settings or reprogram during Rythmol therapy.
  • May interfere with blood cell manufacturing. Immediately contact your doctor if you experience feve’ chills, or sore throat, especially during first 3 months of therapy.
  • May cause or worsen heartbeat irregularities. Doctor should perform electrocardiogram (EKG) before and during treatment.
  • At risk for a lupus-like illness with symptoms such as rashes and arthritic symptoms. Doctor may stop Rythmol if your blood contains ANA (antinuclear antibodies).


HealthSurvey.org provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Rythmol side effects, please contact your healthcare provider