Pharmacokinetic enhancers for HIV drugs

Curr Opin Investig Drugs. 2009 Aug;10(8):775-86.


The HIV protease inhibitor (PI) ritonavir is a potent, mechanism-based inhibitor of cytochrome P450 CYP3A4, an enzyme that is responsible for metabolizing most HIV PIs. Ritonavir is therefore able to enhance the effectiveness of PI treatment by reducing the pill burden, simplifying dosing regimens and improving therapy adherence. Ritonavir coadministration improves the pharmacokinetic (PK) profiles of concomitant PIs, and represents a cornerstone of PI-containing regimens. However, ritonavir is associated with undesirable side effects, such as gastrointestinal problems and lipid disturbances. This review summarizes salient features and limitations associated with the use of ritonavir as a PK enhancer, and briefly describes novel PK enhancers that are in development.

Publication types

  • Review

MeSH terms

  • Cytochrome P-450 CYP3A / physiology
  • Cytochrome P-450 CYP3A Inhibitors*
  • Drug Administration Schedule
  • Drug Synergism
  • Drug Therapy, Combination
  • HIV Infections / drug therapy
  • HIV Protease Inhibitors / pharmacokinetics*
  • HIV Protease Inhibitors / pharmacology*
  • HIV Protease Inhibitors / therapeutic use
  • HIV-1
  • Humans
  • Ritonavir / pharmacokinetics*
  • Ritonavir / pharmacology
  • Ritonavir / therapeutic use


  • Cytochrome P-450 CYP3A Inhibitors
  • HIV Protease Inhibitors
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human
  • Ritonavir