Methadone Side Effects

Brand Names: Dolophine, Methadose, Diskets

Please note - some side effects for Methadone may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Methadone - for the Consumer

Methadone Diskets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Methadone Diskets:

Constipation; dizziness; drowsiness; dry mouth; headache; increased sweating; itching; lightheadedness; nausea; vomiting; weakness.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); confusion; decreased sexual desire or ability; excessive drowsiness; fainting; fast, slow, or irregular heartbeat; hallucinations; loss of appetite; menstrual changes; mental or mood changes (eg, agitation, disorientation, exaggerated sense of well-being); seizures; severe or persistent dizziness or lightheadedness; shortness of breath; slow or shallow breathing; swelling of the arms, feet, or legs; trouble sleeping; trouble urinating; unusual bruising or bleeding.

Methadone

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Methadone:

Constipation; dizziness; drowsiness; dry mouth; headache; increased sweating; itching; lightheadedness; nausea; vomiting; weakness.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); confusion; decreased sexual desire or ability; excessive drowsiness; fainting; fast, slow, or irregular heartbeat; hallucinations; loss of appetite; menstrual changes; mental or mood changes (eg, agitation, disorientation, exaggerated sense of well-being); seizures; severe or persistent dizziness or lightheadedness; shortness of breath; slow or shallow breathing; swelling of the arms, feet, or legs; trouble sleeping; trouble urinating; unusual bruising or bleeding.

Methadone Concentrate

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Methadone Concentrate:

Constipation; dizziness; drowsiness; dry mouth; headache; increased sweating; itching; lightheadedness; nausea; vomiting; weakness.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); confusion; decreased sexual desire or ability; excessive drowsiness; fainting; fast, slow, or irregular heartbeat; hallucinations; loss of appetite; menstrual changes; mental or mood changes (eg, agitation, disorientation, exaggerated sense of well-being); seizures; severe or persistent dizziness or lightheadedness; shortness of breath; slow or shallow breathing; swelling of the arms, feet, or legs; trouble sleeping; trouble urinating; unusual bruising or bleeding.

Methadone Dispersible Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Methadone Dispersible Tablets:

Constipation; dizziness; drowsiness; headache; lightheadedness; nausea; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); excessive drowsiness; fainting; itching; pounding in the chest; seizures; shortness of breath; slow heartbeat; sweating.

Methadone Solution

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Methadone Solution:

Constipation; dizziness; drowsiness; dry mouth; headache; increased sweating; itching; lightheadedness; nausea; pain, redness, or swelling at the injection site; vomiting; weakness.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); confusion; decreased sexual desire or ability; excessive drowsiness; fainting; fast, slow, or irregular heartbeat; hallucinations; loss of appetite; menstrual changes; mental or mood changes (eg, agitation, disorientation, exaggerated sense of well-being); seizures; severe or persistent dizziness or lightheadedness; severe or persistent pain, redness, or swelling at the injection site; shortness of breath; slow or shallow breathing; swelling of the arms, feet, or legs; trouble sleeping; trouble urinating; unusual bruising or bleeding.

Methadone Side Effects - for the Professional

Methadone

Heroin Withdrawal

During the induction phase of Methadone maintenance treatment, patients are being withdrawn from heroin and may therefore show typical withdrawal symptoms, which should be differentiated from Methadone-induced side effects. They may exhibit some or all of the following signs and symptoms associated with acute withdrawal from heroin or other opiates: lacrimation, rhinorrhea, sneezing, yawning, excessive perspiration, goose-flesh, fever, chilliness alternating with flushing, restlessness, irritability, weakness, anxiety, depression, dilated pupils, tremors, tachycardia, abdominal cramps, body aches, involuntary twitching and kicking movements, anorexia, nausea, vomiting, diarrhea, intestinal spasms, and weight loss.

Initial Administration

The initial Methadone dose should be carefully titrated to the individual. Too rapid titration for the patient's sensitivity is more likely to produce adverse effects.

The major hazards of Methadone are respiratory depression and, to a lesser degree, systemic hypotension. Respiratory arrest, shock, cardiac arrest, and death have occurred.

The most frequently observed adverse reactions include lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. These effects seem to be more prominent in ambulatory patients and in those who are not suffering severe pain. In such individuals, lower doses are advisable.

Other adverse reactions include the following:

Body as a Whole – asthenia (weakness), edema, headache

Cardiovascular – arrhythmias, bigeminal rhythms, bradycardia, cardiomyopathy, ECG abnormalities, extrasystoles, flushing, heart failure, hypotension, palpitations, phlebitis, QT interval prolongation, syncope, T-wave inversion, tachycardia, torsade de pointes, ventricular fibrillation, ventricular tachycardia

Digestive – abdominal pain, anorexia, biliary tract spasm, constipation, dry mouth, glossitis

Hematologic and Lymphatic – reversible thrombocytopenia has been described in opioid addicts with chronic hepatitis

Metabolic and Nutritional – hypokalemia, hypomagnesemia, weight gain

Nervous – agitation, confusion, disorientation, dysphoria, euphoria, insomnia, seizures

Respiratory – pulmonary edema, respiratory depression

Skin and Appendages – pruritis, urticaria, other skin rashes, and rarely, hemorrhagic urticaria

Special Senses – hallucinations, visual disturbances

Urogenital – amenorrhea, antidiuretic effect, reduced libido and/or potency, urinary retention or hesitancy

Maintenance on a Stabilized Dose – During prolonged administration of Methadone, as in a Methadone maintenance treatment program, there is usually a gradual, yet progressive, disappearance of side effects over a period of several weeks. However, constipation and sweating often persist.

Methadone Powder

Heroin Withdrawal

During the induction phase of Methadone maintenance treatment, patients are being withdrawn from heroin and may therefore show typical withdrawal symptoms, which should be differentiated from Methadone-induced side effects. They may exhibit some or all of the following symptoms associated with acute withdrawal from heroin or other opiates: lacrimation, rhinorrhea, sneezing, yawning, excessive perspiration, goose-flesh, fever, chilliness alternating with flushing, restlessness, irritability, weakness, anxiety, depression, dilated pupils, tremors, tachycardia, abdominal cramps, body aches, involuntary twitching and kicking movements, anorexia, nausea, vomiting, diarrhea, intestinal spasms, and weight loss.

Initial Administration

The initial Methadone dose should be carefully titrated to the individual. Too rapid titration for the patient's sensitivity is more likely to produce adverse effects.

The major hazards of Methadone, are respiratory depression and, to a lesser degree, systemic hypotension. Respiratory arrest, shock, cardiac arrest, and death have occurred.

The most frequently observed adverse reactions include lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. These effects seem to be more prominent in ambulatory patients and in those who are not suffering severe pain. In such individuals, lower doses are advisable.

Other adverse reactions include the following:

Body as a Whole– asthenia (weakness), edema, headache

Cardiovascular– arrhythmias, bigeminal rhythms, bradycardia, extrasystoles, tachycardia, torsade de pointes, ventricular fibrillation, ventricular tachycardia, ECG abnormalities, prolonged QT interval, T-wave inversion, cardiomyopathy, flushing, heart failure, hypotension, palpitations, phlebitis, syncope

Digestive– abdominal pain, anorexia, biliary tract spasm, constipation, dry mouth, glossitis

Hematologic and Lymphatic– reversible thrombocytopenia has been described in opioid addicts with chronic hepatitis

Metabolic and Nutritional– hypokalemia, hypomagnesemia, weight gain

Nervous– agitation, confusion, seizures, disorientation, dysphoria, euphoria, insomnia

Respiratory– pulmonary edema

Skin and Appendages– pruritis, urticaria, other skin rashes, and rarely, hemorrhagic urticaria

Special Senses– visual disturbances

Urogenital– antidiuretic effect, amenorrhea, urinary retention or hesitancy, reduced libido and/or potency

Maintenance on a Stabilized Dose– During prolonged administration of Methadone, as in a Methadone maintenance treatment program, there is usually a gradual, yet progressive, disappearance of side effects over a period of several weeks. However, constipation and sweating often persist.

Side Effects by Body System

Nervous system

Other neurologic side effects are rare, but include tardive dyskinesia and choreic movements.

Nervous system side effects have included agitation, confusion, disorientation, dysphoria, euphoria, seizures, sleepiness or insomnia, and dizziness.

Cardiovascular

Cardiovascular side effects have included hypotension, bradycardia, arrhythmias, bigeminal rhythms, cardiomyopathy, ECG abnormalities, extrasystoles, flushing, heart failure, palpitations, phlebitis, QT interval prolongation, syncope, T-wave inversion, tachycardia, torsade de pointes, ventricular fibrillation, ventricular tachycardia and edema. Rare cases of cardiac arrest have also been reported.

Gastrointestinal

Methadone may cause contraction of the sphincter of Oddi, which may increase intrabiliary pressure and worsen, rather than relieve, biliary colic.

Gastrointestinal side effects have included constipation, abdominal pain, biliary tract spasm, dry mouth, glossitis, and appetite abnormalities.

Other

Other side effects have included increased sweating which has been common after chronic methadone use.

Hypersensitivity

Hypersensitivity side effects to methadone are rare, and have included rash, pruritus, and edema.

Psychiatric

One study has suggested that detoxification from methadone maintenance therapy may result in the development of an organic mood syndrome in many patients.

Psychiatric side effects have included psychological dependence. A case of obsessive compulsive symptoms precipitated by methadone tapering has been reported.

Endocrine

Endocrine side effects have included stimulation of thyroxine binding globulin (TBG), resulting in increased TBG, total T3 and T4, but unaltered free T3 and T4. Hyperprolactinemia has also been associated with methadone therapy.

Genitourinary

Genitourinary side effects have included amenorrhea, antidiuretic effect, reduced libido and/or potency, urinary hesitancy, and urinary retention.

Respiratory

Respiratory side effects have included pulmonary edema, respiratory depression, and a blunted response to hypercarbia.

Renal

A case of rhabdomyolysis and subsequent acute renal failure following ingestion of large doses of methadone has been reported.

Hematologic

Hematologic side effects associated with methadone have included mild lymphocytosis and increased serum protein, albumin, and globulin.

General

General side effects including asthenia, edema, and headache have been reported.

Metabolic

Metabolic side effects including hypokalemia, hypomagnesemia, and weight gain have been reported.

Ocular

Ocular side effects have included visual disturbances.

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