Methadone Gets an All Clear

Although protease inhibitors have been shown to interfere with other drugs that are metabolized by the same liver enzymes, a new study shows that methadone -- once suspected to be one of the drugs affected by PIs -- is not adversely affected by the anti-HIV medications. A study in the journal Anesthesiology has shown that methadone is not metabolized by the CYP450 enzyme that PI drugs also use, making methadone-replacement therapy safe for HIVers who are also taking PI-based antiretroviral cocktails. To date, clinicians and HIV patients had been warned that mixing PIs and methadone could lead to abnormally high levels of methadone in the bloodstream and a possible overdose of the medication.