Screening for inhibitory effects of antineoplastic agents on CYP3A4 in human liver microsomes.
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Baumhakel M, Kasel D, Rao-Schymanski RA, Bocker R, Beckurts KT, Zaigler M, Barthold D, Fuhr U
Screening for inhibitory effects of antineoplastic agents on CYP3A4 in human liver microsomes.
Int J Clin Pharmacol Ther. 2001 Dec;39(12):517-28.
- PubMed ID
- 11770832 [ View in PubMed]
- Abstract
BACKGROUND: The human cytochrome P450 enzyme CYP3A4 is involved in the metabolism of many anticancer drugs. Since these drugs are usually administered in a polychemotherapy regimen, the objective of this study was to examine their inhibitory potency on CYP3A4 with regard to possible mutual drug interactions. METHOD: CYP3A4 activities in human liver microsomes from 2 donors were determined using the oxidation of the dihydropyridine denitronifedipine, a specific CYP3A4 substrate, at a concentration of 50 microM (= KM). Formation of the pyridine metabolite was measured using HPLC. Inhibitor concentrations used were 0.5, 5 and 50 microg/ml, except for cyclophosphamide and ifosfamide (0.5, 2.5 and 5 mg/ml) and for paclitaxel (0.05, 0.15, 0.5, 1.5 and 5 microg/ml). RESULTS: The following substances showed an inhibitory effect on CYP3A4 (IC50 values for the 2 microsome samples are parenthesized): cyclophosphamide (12.3/9.2 mmol/l), mafosfamide generated 4-OH-cyclophosphamide (152/163 [micromol/l), ifosfamide (3.6/2.5 mmol/l), vinblastine sulfate (20/44 micromol/l), vincristine sulfate (67/176 micromol/l), daunorubicin hydrochloride (206/200 micromol/l), doxorubicin hydrochloride (160/215 micromol/l), teniposide (64/84 micromol/l) and docetaxel (6.4/12.7 micromol/l). No inhibitory effect on CYP3A4 was observed with epirubicin, etoposide, paclitaxel, cytarabine, 5-FU, 6-mercaptopurine, methotrexate, cisplatin, carboplatin, bleomycin, busulfan, chlorambucil and mitomycin. CONCLUSION: Comparing IC50 values with plasma concentrations present during antineoplastic therapy, the agents cyclophosphamide, ifosfamide, vinblastine, teniposide and docetaxel could possibly cause clinical drug interactions by inhibition of CYP3A4. Some recently described clinical interactions with antineoplastic agents may be explained by these results.
DrugBank Data that Cites this Article
- Drug Enzymes
Drug Enzyme Kind Organism Pharmacological Action Actions Daunorubicin Cytochrome P450 3A4 Protein Humans UnknownSubstrateInhibitorDetails Docetaxel Cytochrome P450 3A4 Protein Humans UnknownSubstrateInhibitorDetails Teniposide Cytochrome P450 3A4 Protein Humans UnknownSubstrateInhibitorDetails Vinblastine Cytochrome P450 3A4 Protein Humans UnknownSubstrateInhibitorInducerDetails - Drug Interactions
Drugs Interaction Integrate drug-drug
interactions in your softwareVincristineTeniposide Teniposide may increase the neurotoxic activities of Vincristine.