Methadone adverse events

Methadone 16 mg/day was effective in 29 patients with restless legs syndrome that had not responded to dopamine receptor agonists (9). Most (n = 17) were still taking methadone at follow-up and reported a 75% reduction in symptoms. Of 27 patients, 17 reported at least one adverse event while taking methadone, including constipation (n = 11), fatigue (n = 2), and insomnia, sedation, rash, reduced libido, confusion, and hypertension (one each). Five patients stopped treatment because of adverse events. 

In a randomized controlled trial in 18 pregnant women in the second trimester, a change from short-acting morphine to methadone or buprenorphine was explored (44). The transition was accomplished without any adverse events in mother or fetus and with minimal withdrawal discomfort. 

Of 80 injecting drug users who took two NRTIs + nevirapine (NNRTI), 20 discontinued treatment and 20 had treatment failures (5). Adverse events led to withdrawal of therapy in 10 patients eight had a rash (in one case Stevens-Johnson syndrome) one had liver failure thought to be unrelated to the drugs and one had general intolerance. Two patients taking methadone had opioid withdrawal symptoms, presumably due to induction of methadone metabolism by nevirapine. 

Methadone has Food and Drug Administration indications for the management of pain in adults and for adult narcotic addiction. Adverse events are those expected from opiate exposures gastrointestinal symptoms, CNS depression, and respiratory depression in larger doses, bradycardia, and constipation. Methadone appears to be fairly well tolerated by... 

In a randomized controlled study of the effect of prison-initiated methadone maintenance at 12 months after release, those on prison-initiated methadone maintenance (n = 71) were reported to have a longer duration of treatment in the community than the controls (counseling only, n = 70 counseling and transfer to methadone service after release, n = 70) were less likely to have urine positive for opioids reported reduced use of cocaine had reduced criminal activity and had fewer serious adverse events, such as deaths [17 ]. This study has highlighted the public health implications of optimal prescribing. 

In an open, randomized trial, injectable diacetylmorphine in long-term users of injectable heroin (n=II5) w os compared with methadone (n=III). Those who were given diacetylmorphine had better retention (88% compared with 54%) and greater reduction in rates of illicit drug use (67% compared with 48%). Serious adverse events were more frequent in the diacetylmorphine group (51 events versus 18) overdoses (in 10 patients) and seizures (6 patients) were the most common [22 "]. 

Comparative studies In a randomized comparison of injectable diamorphine (mean dose 392 mg/day n = 115), oral methadone (mean dose 96 mg/day n = 111), and injectable hydromorphone (n = 25) in patients with opioid dependence refractory to treatment, those who received diamorphine had more adverse events (51 events) than those who received methadone (18 events) or hydromorphone (10 events) [50 ]. The most serious events were seizures (seven events with diamorphine in six patients) and overdose (11 events with diamorphine and two with hydromorphone). However, outcome measures were more favorable with diamorphine. The authors suggested that although diamorphine was beneficial it should be delivered in settings where prompt medical intervention could be provided. 

Observational studies The adverse effects profile of methadone has been compared with that of morphine [95. Methadone was associated with fewer adverse events, because it is more lipophilic and has no active metabolites. Symptoms due to methadone overdose generally occur within 9 hours of ingestion with a mean onset of symptoms at 3.2 hours. 

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