The effect of food on the pharmacokinetics of the active metabolite of the new antiasthmatic drug repirinast was investigated in two different studies after oral administration of 300 mg of repirinast. In each study, 12 healthy volunteers received the repirinast dose under fasting or fed conditions in a crossover manner. In one study, a high-fat meal (American breakfast) was used and in another study, a low-fat, high-carbohydrate meal (continental breakfast) was used. Concentrations of the active metabolite in plasma and urine were determined by reversed-phase high-performance liquid chromatography with UV detection. After administration of repirinast with a low-fat and a high-fat meal, the relative bioavailability of the active metabolite increased by factors of 1.9 and 2.4, respectively, as expressed by area under the curve of concentration versus time from 0 to 12 h. The amount excreted into urine doubled after drug administration with both types of food and accounted for approximately 8% of the dose under fasting conditions and approximately 16% of the dose under fed conditions. Maximum concentrations in plasma were different between the two studies: mean maximum concentrations in plasma increased by factors of 1.7 and 3.2 after administration of drug with a low-fat (drug intake immediately after breakfast) and a high-fat breakfast (drug intake just before breakfast), respectively, compared with fasting conditions.