IMPORTANT WARNING:
Methadone injection may be habit forming. Use methadone injection exactly as directed. Do not use a larger dose, take it more often, or use it for a longer period of time or in a different way than prescribed by your doctor. While using methadone injection, discuss with your healthcare provider your pain treatment goals, length of treatment, and other ways to manage your pain. Tell your doctor if you or anyone in your family drinks or has ever drunk large amounts of alcohol, uses or has ever used street drugs, or has overused prescription medications, or has had an overdose, or if you have or have ever had depression or another mental illness. There is a greater risk that you will overuse methadone injection if you have or have ever had any of these conditions. Talk to your healthcare provider immediately and ask for guidance if you think that you have an opioid addiction or call the U.S. Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-HELP.
Methadone injection may cause serious or life-threatening breathing problems, especially during the first 24 to 72 hours of your treatment and any time your dose is increased. Your doctor will monitor you carefully during your treatment. Tell your doctor if you have or have ever had slowed breathing or asthma. Your doctor will probably tell you not to use methadone injection. Also tell your doctor if you have or have ever had lung disease such as chronic obstructive pulmonary disease (COPD; a group of lung diseases that includes chronic bronchitis and emphysema), a head injury, a brain tumor, or any condition that increases the amount of pressure in your brain. The risk that you will develop breathing problems may be higher if you are an older adult or are weak or malnourished due to disease. If you experience any of the following symptoms, call your doctor or get emergency medical treatment: slowed breathing, long pauses between breaths, or shortness of breath.
Taking certain other medications during your treatment with methadone injection may increase the risk that you will experience serious, life-threatening side effects such as breathing problems, sedation, or coma. Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Your doctor may need to change the doses of your medications and will monitor you carefully. If you use methadone injection with other medications and you develop any of the following symptoms, call your doctor immediately or seek emergency medical care: unusual dizziness, lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness. Be sure that your caregiver or family members know which symptoms may be serious so they can call the doctor or emergency medical care if you are unable to seek treatment on your own.
Drinking alcohol, taking prescription or nonprescription medications that contain alcohol, or using street drugs during your treatment with methadone injection increases the risk that you will experience serious, life-threatening side effects. Do not drink alcohol, take prescription or nonprescription medications that contain alcohol, or use street drugs during your treatment.
Do not allow anyone else to use your medication. Methadone injection may harm or cause death to other people who take your medication, especially children. Store methadone injection in a safe place so that no one else can take it accidentally or on purpose. Be especially careful to keep methadone injection out of the reach of children. Keep track of how much liquid is left so you will know if any medication is missing. Dispose of any unwanted methadone injection properly according to instructions. (See STORAGE and DISPOSAL.)
Methadone injection may cause QT prolongation (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death). Tell your doctor if you or anyone in your family has or has ever had long QT syndrome (an inherited condition in which a person is more likely to have QT prolongation) or if you have or ever had a slow or irregular heartbeat, low blood levels of potassium or magnesium, or heart disease. Some medications when taken with methadone injection may increase the risk of QT prolongation occurring. Be sure and tell your doctor and pharmacist what medications you are taking before starting methadone. If you experience any of the following symptoms, call your doctor immediately: pounding heartbeat, dizziness, lightheadedness, or fainting.
Tell your doctor if you are pregnant or plan to become pregnant. If you use methadone injection regularly during your pregnancy, your baby may experience life-threatening withdrawal symptoms after birth. Tell your baby's doctor right away if your baby experiences any of the following symptoms: irritability, hyperactivity, abnormal sleep, high-pitched cry, uncontrollable shaking of a part of the body, vomiting, diarrhea, or failure to gain weight.
Talk to your doctor about the risks of using methadone injection for your condition.
Use of methadone to treat opiate addiction:
If you have been addicted to an opiate (narcotic drug such as heroin), and you are using methadone injection to help you stop taking or continue not taking the drug, you must enroll in a treatment program. The treatment program must be approved by the state and federal governments and must treat patients according to specific federal laws. You may have to take your medication at the treatment program facility under the supervision of the program staff. Ask your doctor or the treatment program staff if you have any questions about enrolling in the program or taking or getting your medication.