Methadone

Methadone is a powerful narcotic drug in the same class as heroin. This class is known as the opioids.

Purpose

Methadone, formerly known as dolophine, is a psychoactive drug, meaning that it affects the mind or behavior. It belongs to the class of opioids, drugs that share some of the analgesic properties, and mimic the action of some of the body's naturally occurring chemicals called peptides, such as endorphins and enkephalines.

Methadone is used to relieve chronic pain in cancer patients and as a maintenance drug to control withdrawal symptoms in people undergoing treatment for opiate addiction.

In opiate addiction treatment, methadone blocks the opioid receptors of the brain that bind opiates such as heroin. The blocking of these receptors leads to two major effects:

• because these chemical receptors remain blocked by methadone for up to 24 hours, even if a person addicted to heroin takes heroin after the administration of methadone, this person is not likely to feel the same effects of the heroin as he or she previously felt;
• because the action of methadone is associated with slower and less intense withdrawal symptoms than those of heroin, the patient can experience milder opiate effects while the addiction is being treated and avoid the unpleasant withdrawal symptoms associated with heroin.

Methadone has also been shown to reduce cravings for heroin while not altering a person's mood.

Precautions

Methadone magnifies the effects of alcohol and other central nervous system depressants, such as anti-histamines, cold medicines, sedatives, tranquilizers, other prescription and over-the-counter (OTC) pain medications, barbiturates, seizure medications, muscle relaxants, and certain anesthetics including some dental anesthetics. Alcohol and other central nervous system depressants should not be taken or consumed while methadone is being taken.

Methadone is a powerful narcotic. It can cause some people to feel drowsy, dizzy, or light-headed. People taking methadone should not drive a car or operate machinery.

Intentional or accidental overdose of methadone can lead to unconsciousness, coma, or death. The signs of methadone overdose include confusion, difficulty speaking, seizures, severe nervousness or restlessness, severe dizziness, severe drowsiness, and/or slow or troubled breathing. These symptoms are increased by alcohol or other central nervous system (CNS) depressants. Anyone who feels that he or she, or someone else, may have over-dosed on methadone, or a combination of methadone and other central nervous system depressants, should seek emergency medical attention for that person at once.

Description

A typical adult dosage for methadone is 5-20 mg as an oral solution, 2.5-10 mg as an oral tablet or injection, every four to eight hours as necessary for pain. When used for detoxification, methadone is initially given in a dose of 15-100 mg per day as an oral solution. This dose is then decreased until the patient no longer requires the medication. The injection form of methadone is only used for detoxification in patients who are unable to take the medication by mouth.

Preparation

No preparation is generally necessary prior to the intake of methadone as a pain reliever. In cases of maintenance treatments, it is important to be sure that the patient is not currently intoxicated by alcohol, heroin, other opioids, or taking other central nervous system depressants.

Aftercare

Patients receiving methadone should be monitored for adverse reactions to this drug, and/or possible accidental overdose.

Risks

Methadone can interfere with or exacerbate certain medical conditions. For these reasons, it is important that the prescribing physician be informed of any current case, or history of:

• alcohol abuse
• brain disease or head injury
• colitis
• drug dependency, particularly of narcotics
• emotional problems
• emphysema, asthma, or other chronic lung disease
• enlarged prostate
• gallstones or gallbladder disease
• heart disease
• kidney disease
• liver disease
• problems with urination
• seizures
• underactive thyroid

Side effects

The most common side effects of methadone include:

• constipation
• dizziness
• drowsiness
• itching
• nausea
• urine retention
• vomiting

Less common side effects of methadone include:

• abnormally fast or slow heartbeat
• blurred or double vision
• cold, clammy skin
• depression or other mood changes
• dry mouth
• fainting
• hallucinations
• hives
• loss of appetite
• nightmares or unusual dreams
• pinpoint pupils of the eyes
• redness or flushing of the face
• restlessness
• rigid muscles
• ringing or buzzing in the ears
• seizure
• severe drowsiness
• skin reaction at the site of injection
• stomach cramps or pain
• sweating
• trouble sleeping (insomnia)
• yellowing of the skin or whites of the eyes

Normal results

Normal results after the administration of methadone to treat chronic pain is the alleviation of that patient's pain, at least to the point where the pain is bearable.

The normal result of methadone treatment to control heroin addiction is that the patient reduces heroin intake almost immediately upon starting methadone treatments, followed by complete abstinence, usually within two weeks after starting treatment.