Methadone

Most of these side effects will get better or go away as the body gets used to the medication.

Common side effects include:

• Dizziness or light-headedness (Rise slowly over several minutes from sitting or lying position).
• Drowsiness. Do not drive or operate heavy machinery if affected
• Constipation
• Nausea or vomiting

Inform your doctor if the side effects above become severe and bothersome.

Rare but serious effects may sometimes occur. Contact the doctor as soon as possible if any of the following are noticed:

• Allergic reactions: Skin rash, itching, difficulty in breathing, swelling of face, lips, tongue or throat
• Shallow breathing
• Severe dizziness or passing out
• Fast heartbeat
• Mental alteration
• Feeling extremely tired or weak
• Seizures (fits)

Avoid alcoholic drink.

Avoid taking grapefruit or grapefruit juice while taking this medicine.