Abstract
Pemirolast potassium is oral nonbronchodilator antiallergy agent evaluated for the therapy of asthma. Its pharmacokinetics in children with asthma has not been studied in detail. The relation between plasma concentrations of pemirolast potassium and its clinical efficacy in asthmatic children was evaluated.
Fourteen children with asthma received pemirolast potassium, 0.4mg/kg/day, given two divided doses, for at least 2 weeks. Plasma levels of pemirolast potassium were determined and, symptoms and concomitant medications were scored.
Within 5 hours after drug administration, the plasma levels of pemirolast potassium in all patients were above the effective plasma level of drug, 0.266μg/ml, and they had no asthma symptoms. Between 5 and 10 hours after drug administration, the children, whose plasma levels of drug fell below 0.266μg/ml, became symptomatic. In 6 patients who received the same doses of pemirolast potassium for 6 months, wide individual variations were observed in the drug's half life and nadir plasma levels. Total scores of symptom scores and concomitant medication scores were decreased in patients whose nadir plasma concentrations of pemirolast potassium were above 0.16μg/ml and were not decreased in patients with low nadir plasma level of pemirolast potassium during treatment with pemirolast potassium.
To establish the optimal dose, the pharmacokinetics of pemirolast potassium need to be evaluated in asthmatic children. Large doses may be required to achieve nadir plasma levels neaby 0.266μg/ml in children who exhibit low plasma levels of pemirolast potassium.
