The Pharmacokinetic Interaction between Theophylline and Leukotriene Receptor Antagonist, Pranlukast.

A pharmacokinetic study of theophylline and leukotriene receptor antagonist, pranlukast, was performed in 7 patients. After theophylline (100 to 200 mg twice daily) was administered for at least 4 weeks, pranlukast (225 mg twice daily) was concomitantly given for 4 to 8 weeks. The serum theophylline concentrations and the pharmacokinetic parameters of theophylline were measured before and after the pranlukast administrations. The distribution volume of theophylline at a steady state slightly increased after the concomitant pranlukast administration. However, the other parameters including the clearance, lag time, half-life, maximum and minimum serum concentrations of theophylline all remained unchanged after the pranlukast administration. The steady state concentrations of theophylline were not affected by the pranlukast intake. These results therefore indicate that no pharmacokinetic interaction exists in the conbination treatment of theophylline and pranlukast.