Drug interactions between opioids and antiretroviral medications: interaction between methadone, LAAM, and nelfinavir

Am J Addict. 2004 Mar-Apr;13(2):163-80. doi: 10.1080/10550490490436037.


Understanding drug interactions between antiretrovirals and opiate therapies may decrease toxicities and enhance adherence, with improved HIV outcomes in injection drug users. We report results of a clinical pharmacology study designed to examine the interaction of the protease inhibitor, nelfinavir, with methadone and LAAM (N = 48). Nelfinavir decreased methadone exposure, but no withdrawal was observed over the five day study period. LAAM and dinorLAAM concentrations were decreased, while norLAAM concentrations were increased, with minimal overall change in LAAM/metabolite exposure. Methadone and LAAM did not affect nelfinavir concentrations, but methadone decreased M8 metabolite exposure. While no toxicities were observed, clinicians should be aware of the potential for drug interactions when patients require treatment with nelfinavir and these opiate medications.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acquired Immunodeficiency Syndrome / complications*
  • Acquired Immunodeficiency Syndrome / drug therapy*
  • Adult
  • Cytochrome P-450 Enzyme System / metabolism
  • Drug Interactions
  • Female
  • HIV Protease Inhibitors / pharmacokinetics
  • HIV Protease Inhibitors / therapeutic use*
  • Humans
  • Male
  • Methadone / pharmacokinetics
  • Methadone / therapeutic use*
  • Methadyl Acetate / pharmacokinetics
  • Methadyl Acetate / therapeutic use*
  • Narcotics / pharmacokinetics
  • Narcotics / therapeutic use*
  • Nelfinavir / pharmacokinetics
  • Nelfinavir / therapeutic use*
  • Substance-Related Disorders / complications*
  • Substance-Related Disorders / rehabilitation*


  • HIV Protease Inhibitors
  • Narcotics
  • Cytochrome P-450 Enzyme System
  • Nelfinavir
  • Methadyl Acetate
  • Methadone