Potential of pranlukast and zafirlukast in the inhibition of human liver cytochrome P450 enzymes.

Article Details

Citation

Liu KH, Lee YM, Shon JH, Kim MJ, Lee SS, Yoon YR, Cha IJ, Shin JG

Potential of pranlukast and zafirlukast in the inhibition of human liver cytochrome P450 enzymes.

Xenobiotica. 2004 May;34(5):429-38. doi: 10.1080/00498250410001691253 .

PubMed ID
15370959 [ View in PubMed
]
Abstract

1. The potential of zafirlukast to inhibit several human cytochrome P450 enzymes is well known. However, pranlukast, a structural analogue of zafirlukast, has not been studied. Accordingly, the inhibitory potential of pranlukast was evaluated and compared with that of zafirlukast, a known CYP2C9 inhibitor, in in vitro microsomal incubation studies. 2. Both pranlukast and zafirlukast showed moderate inhibition of CYP2C9-catalysed tolbutamide 4-methylhydroxylation, competitively inhibiting tolbutamide 4-methylhydroxylation with estimated mean K(i) values of 3.82 +/- 0.50 and 5.86 +/- 0.08 microM, respectively. 3. Pranlukast had no effect on CYP2C19-catalysed S-mephenytoin 4'-hydroxylation or CYP3A4-catalysed midazolam 1-hydroxylation. However, zafirlukast showed minor inhibition of these reactions. Neither pranlukast nor zafirlukast inhibited CYP1A2-catalysed phenacetin O-deethylation, CYP2D6-catalysed dextromethorphan O-demethylation or CYP2E1-catalysed chlorzoxazone 6-hydroxylation. 4. The results suggest that like zafirlukast, pranlukast also has the potential moderately to inhibit CYP2C9-catalysed tolbutamide 4-methylhydroxylation. Therefore, the inhibitory potential of pranlukast should be considered when it is co-administered with CYP2C9 substrates with narrow therapeutic ranges (e.g. S-warfarin, phenytoin).

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
PranlukastCytochrome P450 2C9ProteinHumans
No
Inhibitor
Details
ZafirlukastCytochrome P450 3A4ProteinHumans
Unknown
Substrate
Inhibitor
Details