Methadone

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Jan 25, 2024

Side Effects


Methadone (Dolophine) Side Effects

Possible side effects of methadone are listed below. Tell your doctor if these side effects are severe or do not go away in a few days.

  • Stomach pain
  • Headache
  • Dry mouth
  • Weight gain
  • Flushing or feeling of warmth
  • Sore tongue
  • Difficulty urinating
  • Vision problems
  • Mood changes
  • Sleep difficulties

Rarely, methadone can cause more serious side effects. Call your healthcare provider or emergency services immediately if you develop the following signs and symptoms:

  • Seizures
  • Skin rash, hives, itching
  • Swelling of the face, eyes, lips, tongue, or throat
  • Difficulty breathing or swallowing
  • Hoarseness
  • Extreme drowsiness
  • Agitation, confusion, hallucinations, fever, shivering, excessive sweating, fast heartbeat, loss of coordination, severe muscle stiffness, muscle twitching
  • Weakness, dizziness, nausea, vomiting, loss of appetite
  • Erectile dysfunction (inability to achieve or keep an erection)
  • Menstrual irregularities
  • Decreased libido (sexual desire)

The above list may not include all the potential adverse effects of methadone. Contact your doctor for medical advice about side effects if they are unusual or severe or do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Methadone (Dolophine) Overdose: In case of an accidental or intentional overdose of methadone, contact your doctor immediately. You can also call the National Poison Control Center at 1-800-222-1222. If a person cannot be awakened, has trouble breathing, has collapsed, or has had a seizure, call 911.

Source: FDA