Background: Recently, a novel percutaneous adhesive tulobuterol preparation, HN-078, has been developed and tests using healthy adult subjects have indicated it to be effective for controlling exacerbations early in the morning if applied at bedtime. In children, percutaneous application is very important to eliminate side effects, including abdominal pain and appetite loss.
Objective: We report the pharmacokinetics and pharmacodynamics of tulobuterol patch, HN-078, in the treatment of childhood asthma.
Methods: Single applications of HN-078 were applied transdermally in six children with asthma who had been admitted to a hospital. Subjects weighing less than 30 kg received 1 mg of tulobuterol while subjects weighing 30 kg or above received 2 mg on the chest for 24 hours. Serum tulobuterol levels and peak expiratory flow rate were determined before and after each application.
Results: Cmax of tulobuterol was determined to be 1.33 +/- 0.21 ng/mL, Tmax was 14.0 +/- 2.0 hours, and AUCO-t was 27.1 +/- 4.2 ng.hr/mL. These pharmacokinetic parameters per body surface area of children were nearly equivalent to those of adults obtained in other studies. Peak expiratory flow rate values obtained after application of HN-078 significantly increased in comparison to those obtained before application. No significant changes were observed in pulse rate or blood pressure, and no side effects were found with regard to the subjective symptoms and skin conditions.
Conclusions: These results suggest that the patch formulation of tulobuterol, HN-078, will be very useful for the treatment of pediatric asthma. It is especially significant that no side effects were observed.