There has been recent concern about the association between high dose methadone and prolongation of QTc in the electrocardiogram. QTc is the time from the beginning of the QRS complex to the end of the T have as measured on an electrocardiogram and corrected for heart rate. To date, no association has been made between methadone and buprenorphine in commonly used doses and prolonged QTc. Electr...

BACKGROUND Buprenorphine is used in the treatment of opioid dependence. Due to its pharmacology, the transfer from methadone to buprenorphine may precipitate withdrawal symptoms. METHODS Methadone maintained patients with clinical indicators of stability who were seeking withdrawal from methadone were recruited from three Australian states. Patients on methadone doses between 30 and 40 mg wer...

Methadone is a long-acting opioid with considerable unexplained interindividual variability in clearance. Cytochrome P450 2B6 (CYP2B6) mediates clinical methadone clearance and metabolic inactivation via N-demethylation to 2-ethyl-1,5-dimethyl3,3-diphenylpyrrolidine (EDDP). Retrospective studies suggest that individuals with the CYP2B6*6 allelic variant have higher methadone plasma concentratio...

OBJECTIVES This case report aims to help healthcare providers and methadone clinic patients to recognize one of the less recognized adverse effects of methadone, hyperhidrosis, and to suggest oxybutynin as a possible solution. METHODS A 35-year-old man on methadone maintenance therapy presented with excessive sweating, which began promptly after methadone was introduced. Urine toxicology was ...

Methadone is a mu-opioid receptor agonist used for treating opiate dependence. The range of effective methadone doses is broad. Part of the large inter-individual variability in efficacy may be accounted for by genetic factors. Methadone is a substrate of the transporter P-glycoprotein (P-gp) 170 that is encoded by the ABCB1 (MDR1) gene. Thus, P-gp variants may play a role in methadone absorpti...

AIMS To perform a toxicological analysis of deaths involving methadone and to determine the fatal concentration of methadone in such deaths. METHODS Deaths in which methadone was mentioned in the cause of death were identified. Deaths were divided into those associated with methadone only and deaths in which the cause of death was a combination of methadone and other drugs. Toxicological find...

BACKGROUND Methadone is a unique µ-opioid receptor agonist. Although several researchers have insisted that the pharmacological effects of methadone are mediated through the blockade of NMDA receptor, the underlying mechanism by which methadone exerts its distinct pharmacological effects compared to those of other µ-opioid receptor agonists is still controversial. In the present study, we furth...

Methadone was found to significantly inhibit the in vitro and in vivo growth of human lung cancer cells. The in vitro growth inhibition (occurring at 1-100 nM methadone) was associated with changes in cell morphology and viability detectable within 1 hr and was irreversible after a 24-hr exposure to the drug. These effects of methadone could be reversed in the first 6 hr by naltrexone, actinomy...

The l-isomer of methadone possesses opioid activity, whereas the d-isomer is weak or inactive as an opioid. Both d- and l-methadone have been shown to bind to the N-methyl-D-aspartate (NMDA) receptor. To determine whether d-methadone has functional, in vivo NMDA receptor antagonist activity, the antinociceptive effects of d-methadone were evaluated in the rat tail-flick and formalin tests. Cumu...

Research demonstrates that drug treatment staff members' knowledge and attitudes about methadone are positively correlated with treatment success among opiate-dependent clients. However the bulk of this research is on outpatient treatment in methadone clinics. This study examined a residential treatment program that allowed clients on methadone, a rare treatment opportunity that is growing nati...