What side effects can this medication cause?

Methadone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• weakness
• headache
• nausea
• vomiting
• constipation
• loss of appetite
• weight gain
• stomach pain
• dry mouth
• sweating
• flushing
• difficulty urinating
• swelling of the hands, arms, feet, and legs
• mood changes
• vision problems
• difficulty falling asleep or staying asleep
• decreased sexual desire or ability
• missed menstrual periods

Some side effects can be serious. If you experience any of the following symptoms or those mentioned in the IMPORTANT WARNING section, call your doctor immediately:

• seizures
• itching
• hives
• rash

Methadone may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.