Pharmacokinetic interaction between rifampin and the combination of indinavir and low-dose ritonavir in HIV-infected patients

Clin Infect Dis. 2004 Feb 1;38(3):426-9. doi: 10.1086/380794. Epub 2004 Jan 12.


Rifampin is an important drug in the treatment of tuberculosis, but administration of rifampin in combination with protease inhibitors is complicated because of drug-drug interactions. A prospective, controlled, multiple-dose study involving 6 HIV-infected patients receiving a combination of indinavir (800 mg) and ritonavir (100 mg) twice a day was performed to evaluate whether the inducing effect of rifampin on the drug-metabolizing enzyme cytochrome P450 (CYP) 3A4 could be overcome by the inhibitory effect of ritonavir. Pharmacokinetic evaluations of steady-state concentrations of indinavir and ritonavir were performed before and after administration of rifampin (300 mg every day for 4 days). An 87% reduction (from 837 to 112 ng/mL) in median indinavir and a 94% reduction (from 431 to 27 ng/mL) in median ritonavir concentrations were seen 12 h after the last dose of rifampin was administered (P=.031). These results strongly indicate that the administration of rifampin with a combination of indinavir (800 mg) and ritonavir (100 mg) could lead to subtherapeutic concentrations of indinavir.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antitubercular Agents / pharmacokinetics*
  • Drug Interactions
  • HIV Infections / metabolism*
  • HIV Protease Inhibitors / administration & dosage
  • HIV Protease Inhibitors / pharmacokinetics*
  • Humans
  • Indinavir / pharmacokinetics
  • Middle Aged
  • Prospective Studies
  • Rifampin / pharmacokinetics*
  • Ritonavir / administration & dosage
  • Ritonavir / pharmacokinetics


  • Antitubercular Agents
  • HIV Protease Inhibitors
  • Indinavir
  • Ritonavir
  • Rifampin