Methadone manufacturers

Methadone is manufactured as tablets, diskettes (also known as biscuits), and liquid. People who use the drug illegally often inject either the liquid form or crushed and dissolved tablets. Methadone is detectable in a person s bloodstream seven to 10 days after use. 

Increased CNS depression may occur with opioids and other CNS depressants such as hypnotics and manufacturers of several opiates specifically mention that barbiturates can potentiate sedation, respiratory depression, and hypotension. A reduction in dosage may be required. One manufacturer of methadone contraindicates the use of the injection, but not the oral solution, with other CNS depressants including barbiturates however, other manufacturers warn of the potential for increased CNS depression, but do not contraindicate barbiturates. ... 

An isolated report describes a marked increase in the effects of dextromoramide, resulting in coma, in a man treated with trole-andomycin. Macrolides including troleandomycin and erythromycin are predicted to increase buprenorphine bioavailability. Similarly, the metabolism of hydromorphone is reduced by troleandomycin in vitro. Some manufacturers have su ested that the metabolism of methadone and oxycodone may be decreased by these macrolides, but there do not appear to be any clinical reports confirming this. 

A randomised, crossover study in 12 healthy subjects found that troleandomycin did not significantly affect oral or intravenous methadone bioavailability. Troleandomycin caused only a small reduction in methadone A-demethylation after oral methadone, suggesting only a small role for CYP3A4 in human methadone metabolism. However, one manufacturer of methadone warns that its clearance may be decreased if it is given with drugs that inhibit CYP3A4 activity, such as some maerolide antibacterials. ... 

The US manufacturers of delavirdine suggest that the methadone dose may need to be reduced however, the effects in the study reported are small, and would not be expected to be of clinical significance. 

The manufacturers of nelfinavir say that in a pharmacokinetic study nelfmavir reduced the concentrations of methadone by 47%. " However, despite this reduction none of the subjects develop withdrawal symptoms, although due to the pharmacokinetic changes, it should be expect that some patients might experience withdrawal symptoms. " A retrospective study of HIV-positive patients taking methadone reported that 5 out of 30 patients (17%) requir methadone adjustments (mean 26 mg). The use of nelfmavir with methadone was effective and well tolerated. ... 

The manufacturers of tipranavir state that use of methadone with tiprana-vir boosted by low-dose ritonavir (200 mg) can result in a decrease in methadone levels of about 50%, which may require dose increase in some patients. " ... 

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