During the induction phase of methadone maintenance treatment, patients are being withdrawn from heroin and may therefore show typical withdrawal symptoms, which should be differentiated from methadone-induced side effects.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.
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.
REPORTS OF SUSPECTED METHADOSE SIDE EFFECTS / ADVERSE REACTIONS
Below is a sample of reports where side effects / adverse reactions may be related to Methadose. The information is not vetted and should not be considered as verified clinical evidence.
Possible Methadose side effects / adverse reactions in 53 year old female
Reported by a consumer/non-health professional from United States on 2011-11-02
Patient: 53 year old female
Adverse event resulted in: hospitalization
Dosage: 30 mg q8h
Administration route: Oral
Dosage: 15 mg q3 hours as needed
Dosage: 250 mcg q72 hours
Dosage: 100 mcg
Dosage: 175 mg/day
Indication: Breakthrough Pain
Dosage: 20 mg q8h
Administration route: Oral
Dosage: 100 mcg q72 hours
Dosage: 150 mcg
Dosage: 30 mg q12 hours
Possible Methadose side effects / adverse reactions in 42 year old female
Reported by a health professional (non-physician/pharmacist) from United States on 2011-11-09
Patient: 42 year old female
Reactions: Overdose, Visual Impairment, Pain, Sedation, Headache, Drug Withdrawal Syndrome, Constipation
Dosage: 13 tablets prior to arriving at the clinic
Dosage: 10 mg, tid
Dosage: 4 mg, qid
Other drugs received by patient: Trazodone Hydrochloride; Aripiprazole; Topiramate; Celecoxib; Bupropion HCL
Possible Methadose side effects / adverse reactions in 32 year old female
Reported by a health professional (non-physician/pharmacist) from France on 2011-11-28
Patient: 32 year old female
Reactions: Maternal Exposure During Pregnancy, Abortion Spontaneous
Dosage: mean dose 38 +/- 31 mg/day at the end of pregnancy
Dosage: mean dose 42 +/-32 mg/day at beginning of pregnancy