Ritonavir and efavirenz significantly alter the metabolism of erlotinib--an observation in primary cultures of human hepatocytes that is relevant to HIV patients with cancer

Erlotinib is approved for the treatment of non-small cell lung and pancreatic cancers, and is metabolized by CYP3A4. Inducers and inhibitors of CYP3A enzymes such as ritonavir and efavirenz, respectively, may be used as part of the highly active antiretroviral therapy drugs to treat patients with human immunodeficiency virus (HIV). When HIV patients with a malignancy need treatment with erlotinib, there is a potential of as-yet-undefined drug-drug interaction. We evaluated these interactions using human hepatocytes benchmarked against the interaction of erlotinib with ketoconazole and rifampin, the archetype cytochrome P450 inhibitor and inducer, respectively. Hepatocytes were treated with vehicle [0.1% dimethylsulfoxide, ritonavir (10 μM)], ketoconazole (10 μM), efavirenz (10 μM), or rifampin (10 μM) for 4 days. On day 5, erlotinib (5 μM) was incubated with the above agents for another 24-48 hours. Concentrations of erlotinib and O-desmethyl erlotinib were quantitated in collected samples (combined lysate and medium) using liquid chromatography and tandem mass spectrometry. The half-life (t(½)) of erlotinib increased from 10.6 ± 2.6 to 153 ± 80 and 23.9 ± 4.8 hours, respectively, upon treatment with ritonavir and ketoconazole. The apparent intrinsic clearance (C(Lint, app)) of erlotinib was lowered 16-fold by ritonavir and 1.9-fold by ketoconazole. Efavirenz and rifampin decreased t1/2 of erlotinib from 10.3 ± 1.1 to 5.0 ± 1.5 and 3.4 ± 0.2 hours, respectively. Efavirenz and rifampin increased the C(Lint, app) of erlotinib by 2.2- and 2-fold, respectively. Our results suggest that to achieve desired drug exposure, the clinically used dose (150 mg daily) of erlotinib may have to be significantly reduced (25 mg every other day) or increased (300 mg daily), respectively, when ritonavir or efavirenz is coadministered.

Medienart:

E-Artikel

Erscheinungsjahr:

2013

Erschienen:

2013

Enthalten in:

Zur Gesamtaufnahme - volume:41

Enthalten in:

Drug metabolism and disposition: the biological fate of chemicals - 41(2013), 10 vom: 07. Okt., Seite 1843-51

Sprache:

Englisch

Beteiligte Personen:

Pillai, Venkateswaran C [VerfasserIn]
Venkataramanan, Raman [VerfasserIn]
Parise, Robert A [VerfasserIn]
Christner, Susan M [VerfasserIn]
Gramignoli, Roberto [VerfasserIn]
Strom, Stephen C [VerfasserIn]
Rudek, Michelle A [VerfasserIn]
Beumer, Jan H [VerfasserIn]

Links:

Volltext

Themen:

14-alpha Demethylase Inhibitors
Alkynes
Anti-HIV Agents
Benzoxazines
Cyclopropanes
DA87705X9K
Efavirenz
Erlotinib Hydrochloride
HIV Protease Inhibitors
JE6H2O27P8
Journal Article
Ketoconazole
Nucleic Acid Synthesis Inhibitors
O3J8G9O825
Quinazolines
R9400W927I
Research Support, N.I.H., Extramural
Rifampin
Ritonavir
VJT6J7R4TR

Anmerkungen:

Date Completed 14.04.2014

Date Revised 21.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1124/dmd.113.052100

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM22972034X