Inhibition of human cytochrome P450 enzymes by 1,4-dihydropyridine calcium antagonists: prediction of in vivo drug-drug interactions.

Article Details

Citation

Katoh M, Nakajima M, Shimada N, Yamazaki H, Yokoi T

Inhibition of human cytochrome P450 enzymes by 1,4-dihydropyridine calcium antagonists: prediction of in vivo drug-drug interactions.

Eur J Clin Pharmacol. 2000 Feb-Mar;55(11-12):843-52.

PubMed ID
10805063 [ View in PubMed
]
Abstract

OBJECTIVE: 1,4-Dihydropyridine calcium antagonists such as nifedipine are potent vasodilators. It is now commonly agreed that the oxidation of 1,4-dihydropyridine into pyridine, which is one of the main metabolic pathways, is catalysed by the cytochrome P450 (CYP) 3A4 isoform. In the present study, the inhibitory effects of 13 kinds of 1,4-dihydropyridine calcium antagonists clinically used in Japan on human CYP-isoform-dependent reactions were investigated to predict the drug interactions using microsomes from human B-lymphoblast cells expressing CYP. RESULTS: The specific activities for human CYP isoforms included 7-ethoxyresorfin O-deethylation (CYP1A1), phenacetin O-deethylation (CYP1A2), coumarin 7-hydroxylation (CYP2A6), 7-benzyloxyresorufin O-dealkylation (CYP2B6), S-warfarin 7-hydroxylation (CYP2C9), S-mephenytoin 4'-hydroxylaion (CYP2C19), bufuralol 1'-hydroxylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and testosterone 6beta-hydroxylation (CYP3A4). Benidipine and amlodipine competitively inhibited the CYP1A1 activity. Nifedipine, nisoldipine and aranidipine competitively inhibited the CYP1A2 activity. No 1,4-dihydropyridie calcium antagonists used in this study inhibited the CYP2A6 activity. Barnidipine and amlodipine inhibited the CYP2B6 activity. Nicardipine, benidipine, manidipine and barnidipine competitively inhibited the CYP2C9 and CYP2D6 activities. Inhibition extent of the CYP2E1 activity by nifedipine and aranidipine were weak. Nicardipine, benidipine and barnidipine inhibited the CYP2C19 and CYP3A4 activities. Among the human CYP isoforms investigated, the inhibitory effects of 1,4-dihydropyridine calcium antagonists were potent on human CYP1A2, CYP2B6, CYP2C9, CYP2C19 and CYP2D6 as well as CYP3A4. Furthermore, the isoform selectivity of inhibition by 1,4-dihydropyridine calcium antagonists was clarified. CONCLUSIONS: In consideration of the Ki values obtained in the in vitro inhibition study and the concentration of 1,4-dihydropyridine calcium antagonists in human liver, the possibility of in vivo drug interactions of nicardipine and other drugs which are mainly metabolised by CYP2C9 and/or CYP3A4 was suggested. The inhibition of human CYP isoforms by 1,4-dihydropyridine calcium antagonists except nicardipine might be clinically insignificant.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
AmlodipineCytochrome P450 1A1ProteinHumans
Unknown
Inhibitor
Details
AmlodipineCytochrome P450 2B6ProteinHumans
Unknown
Substrate
Inhibitor
Details
AmlodipineCytochrome P450 3A4ProteinHumans
No
Substrate
Inhibitor
Details
BarnidipineCytochrome P450 3A4ProteinHumans
No
Substrate
Inhibitor
Details
BenidipineCytochrome P450 3A4ProteinHumans
No
Substrate
Inhibitor
Details
ManidipineCytochrome P450 2C19ProteinHumans
Unknown
Inhibitor
Details
NicardipineCytochrome P450 2C19ProteinHumans
Unknown
Inhibitor
Details
NicardipineCytochrome P450 2C9ProteinHumans
No
Inhibitor
Details
NicardipineCytochrome P450 2D6ProteinHumans
Unknown
Inhibitor
Details
NicardipineCytochrome P450 2E1ProteinHumans
Unknown
Substrate
Details
NifedipineCytochrome P450 1A2ProteinHumans
Unknown
Substrate
Inhibitor
Details
NifedipineCytochrome P450 2E1ProteinHumans
Unknown
Inhibitor
Details
Drug Interactions
DrugsInteraction