You should not use methadone if you have severe asthma or breathing problems, or a blockage in your stomach or intestines.
MISUSE OF METHADONE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription. Keep the medication in a place where others cannot get to it.
Taking opioid medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.
Fatal side effects can occur if you use opioid medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.
Methadone may cause a life-threatening heart rhythm disorder. Call your doctor at once if you have a headache with chest pain and severe dizziness, and fast or pounding heartbeats. Your heart function may need to be checked during treatment.
Before taking this medicine
You should not use methadone if you are allergic to it, or if you have:
severe asthma or breathing problems; or
a blockage in your stomach or intestines.
To make sure this medicine is safe for you, tell your doctor if you have ever had:
heart problems, long QT syndrome (in you or a family member);
breathing problems, sleep apnea;
a head injury, brain tumor, or seizures;
drug or alcohol addiction, or mental illness;
liver or kidney disease;
urination problems; or
problems with your gallbladder, pancreas, or thyroid.
If you use opioid medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on opioids may need medical treatment for several weeks.
Do not breast-feed. Methadone can pass into breast milk and cause drowsiness, breathing problems, or death in a nursing baby.
