Efavirenz decreases methadone blood concentrations

• Published in: AIDS (London) Vol. 14; no. 9; pp. 1291 - 1292
• Main Authors: MARZOLINI, C, TROILLET, N, TELENTI, A, BAUMANN, P, DECOSTERD, L. A, EAP, C. B
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 16-06-2000
• Subjects: Adult; Anti-HIV Agents - therapeutic use; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiviral agents; Benzoxazines; Biological and medical sciences; CYP3A4; Drug Interactions; efavirenz; Female; HIV Infections - blood; HIV Infections - drug therapy; Human immunodeficiency virus 1; Humans; Lamivudine - therapeutic use; Medical sciences; Methadone - blood; Methadone - pharmacokinetics; Oxazines - adverse effects; Oxazines - therapeutic use; Pharmacology. Drug treatments; Reverse Transcriptase Inhibitors - adverse effects; Reverse Transcriptase Inhibitors - therapeutic use; Stavudine - therapeutic use; Substance Withdrawal Syndrome; Human; Immunopathology; Drug addiction; Enzyme inhibitor; Opiates; AIDS; Concentration; Methadone; Immune deficiency; Efavirenz; Blood plasma; Infection; Case study; Chemotherapy; Treatment; Viral disease; Antiviral; Drug interaction; Withdrawal syndrome
• ISSN: 0269-9370; 1473-5571
• DOI: 10.1097/00002030-200006160-00036

Efavirenz is a potent inhibitor of HIV-1 reverse transcriptase. It induces CYP3A4, an enzyme belonging to the cytochrome P450 complex, and may reduce plasma concentrations of protease inhibitors, another class of drugs used for the treatment of HIV infection. Recently, three cases of withdrawal symptoms occurring in patients on methadone maintenance therapy were reported to us after the initiation of a new drug regimen containing efavirenz. Methadone serum levels could be determined before and after the introduction of efavirenz in one patient.