BACKGROUND: Corticosteroids are cytochrome P450 3A4 substrates, which have been associated with toxicities in patients receiving cytochrome P450 3A4 inhibitors such as human immunodeficiency virus protease inhibitors. In a study in healthy volunteers, ritonavir significantly increased prednisolone exposure. METHODS: We investigated the influence of antiretroviral (ARV) medications on prednisolone pharmacokinetics in 3 groups of 10 human immunodeficiency virus-infected subjects. One group received lopinavir/ritonavir, and another efavirenz, as part of their ARV regimen; a third group did not receive ARV medications. Each subject received a single 20-mg prednisone dose followed by serial blood sampling for prednisolone. Prednisolone pharmacokinetics were compared among the groups. RESULTS: Area under the concentration-time curve was significantly lower in efavirenz recipients versus subjects receiving lopinavir/ritonavir (geometric mean ratio = 0.60, P = 0.01). Average prednisolone area under the concentration-time curve was higher in subjects taking lopinavir/ritonavir versus subjects not on ARVs; however, this difference was not significant (P > 0.05). CONCLUSIONS: These data indicate that prednisolone concentrations may fluctuate widely when human immunodeficiency virus-positive individuals established on efavirenz therapy change to lopinavir/ritonavir or vice versa.
BACKGROUND: Corticosteroids are cytochrome P450 3A4 substrates, which have been associated with toxicities in patients receiving cytochrome P450 3A4 inhibitors such as human immunodeficiency virus protease inhibitors. In a study in healthy volunteers, ritonavir significantly increased prednisolone exposure. METHODS: We investigated the influence of antiretroviral (ARV) medications on prednisolone pharmacokinetics in 3 groups of 10 humanimmunodeficiency virus-infected subjects. One group received lopinavir/ritonavir, and another efavirenz, as part of their ARV regimen; a third group did not receive ARV medications. Each subject received a single 20-mg prednisone dose followed by serial blood sampling for prednisolone. Prednisolone pharmacokinetics were compared among the groups. RESULTS: Area under the concentration-time curve was significantly lower in efavirenz recipients versus subjects receiving lopinavir/ritonavir (geometric mean ratio = 0.60, P = 0.01). Average prednisolone area under the concentration-time curve was higher in subjects taking lopinavir/ritonavir versus subjects not on ARVs; however, this difference was not significant (P > 0.05). CONCLUSIONS: These data indicate that prednisolone concentrations may fluctuate widely when human immunodeficiency virus-positive individuals established on efavirenz therapy change to lopinavir/ritonavir or vice versa.
Authors: Scott R Penzak; Elizabeth Formentini; Raul M Alfaro; Michael Long; Ven Natarajan; Joseph Kovacs Journal: J Acquir Immune Defic Syndr Date: 2005-12-15 Impact factor: 3.731
Authors: F J Palella; K M Delaney; A C Moorman; M O Loveless; J Fuhrer; G A Satten; D J Aschman; S D Holmberg Journal: N Engl J Med Date: 1998-03-26 Impact factor: 91.245