Effects of polymorphisms of the SLCO2B1 transporter gene on the pharmacokinetics of montelukast in humans

Montelukast, a leukotriene receptor antagonist, is a substrate of organic anion transporting OATP2B1 encoded by the SLCO2B1. We evaluated the effects of six non-synonymous (c.1175C>T, c.1457C>T, c.43C>T, c.935G>A, c.601G>A, and c.644A>T) polymorphisms and one promoter (g.-282G>A) polymorphism on the pharmacokinetics of montelukast. A single dose of 10 mg montelukast was administered in 24 healthy subjects. Its levels were measured up to 24 hours and a pharmacokinetic analysis was performed based on the SLCO2B1 polymorphisms. We did not encounter subjects with c.1175C>T, c.43C>T, or c.644A>T polymorphisms. The remaining SLCO2B1 polymorphisms did not affect plasma levels of montelukast, and pharmacokinetic parameters of montelukast did not differ among genotype groups. Oral clearance results were as follows: (1) 3.3 L/h for c.935GG, 3.0 L/h for c.935GA, and 3.5 L/h for c.935AA; (2) 3.4 L/h for c.1457CC, 2.9 L/h for c.1457CT, and 3.2 L/h for c.1457TT; (3) 3.2 L/h for c.601GG, 3.4 L/h for c.601GA, and 3.4 L/h for c.601AA; (4) 3.2 L/h for g.-282GG, 3.4 L/h for g.-282GA, and 3.2 L/h for g.-282AA. The findings suggest that SLCO2B1 polymorphisms do not affect the pharmacokinetics of montelukast and that SLCO2B1 polymorphisms appear to be a minor determinant of inter-individual variability of montelukast.