Yeh RF, Gaver VE, Patterson KB, Rezk NL, Baxter-Meheux F, Blake MJ, Eron JJ, Klein CE, Rublein JC, Kashuba ADM. Lopinavir/ritonavir induces the hepatic activity of cytochrome P450 enzymes CYP2C9, CYP2C19, and CYP1A2 but inhibits the hepatic and intestinal activity of CYP3A as measured by a phenotyping drug cocktail in healthy volunteers.
J Acquir Immune Defic Syndr 2006;
42:52-60. [PMID:
16639344 DOI:
10.1097/01.qai.0000219774.20174.64]
[Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE
The effect of lopinavir/ritonavir (LPV/r) administration on cytochrome P450 (CYP) enzyme activity was quantified using a phenotyping biomarker cocktail. Changes in CYP2C9, CYP2C19, CYP3A, CYP1A2, N-acetyltransferase-2 (NAT-2), and xanthine oxidase (XO) activities were evaluated using warfarin (WARF) + vitamin K, omeprazole (OMP), intravenous (IV) and oral (PO) midazolam (MDZ), and caffeine (CAF).
DESIGN
: Open-label, multiple-dose, pharmacokinetic study in healthy volunteers.
METHODS
Subjects (n = 14) simultaneously received PO WARF 10 mg, vitamin K 10 mg, OMP 40 mg, CAF 2 mg/kg, and IV MDZ 0.025 mg/kg on days (D) 1 and 14, and PO MDZ 5 mg on D2 and D15. LPV/r (400/100 mg twice daily) was administered on D4-17. CYP2C9 and CYP2C19 activities were quantified by S-WARF AUC0-inf and OMP/5-hydroxy OMP ratio, respectively. CYP1A2, NAT-2, and XO activities were quantified by urinary CAF metabolite ratios. Hepatic and intestinal + hepatic CYP3A activities were quantified by IV (CL) and PO (CL/F) MDZ clearance, respectively.
RESULTS
After LPV/r therapy, CYP2C9, CYP2C19, and CYP1A2 activity increased by 29%, 100%, and 43% (P = 0.001, 0.046, and 0.001), respectively. No changes were seen in NAT-2 or XO activity. Hepatic and intestinal + hepatic CYP3A activity decreased by 77% (P < 0.001) and 92% (P = 0.001), respectively.
CONCLUSION
LPV/r therapy results in modest induction of CYP1A2 and CYP2C9 and potent induction of CYP2C19 activity. Increasing doses of concomitant medications metabolized by these enzymes may be necessary. LPV/r inhibited intestinal CYP3A to a greater extent than hepatic CYP3A activity. Doses of concomitant CYP3A substrates should be reduced when combined with LPV/r, although intravenously administered compounds may require less of a relative dose reduction than orally administered compounds.
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