PHARMACOKINETICS AND PHARMACODYNAMICS OF THE TULOBUTEROL PATCH, HN-078, IN CHILDHOOD ASTHMA

Background: Recently, a novel percutaneous adhesive tulobuterol prepar ation, HN-078, has been developed and tests using healthy adult subjec ts have indicated it to be effective for controlling exacerbations ear ly in the morning if applied at bedtime. In children, percutaneous app lication is very important to eliminate side effects, including abdomi nal pain and appetite loss. Objective: We report the pharmacokinetics and pharmacodynamics of tulobuterol patch, KN-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 tulobuter ol while subjects weighing 30 kg or above received 2 mg on the chest f or 24 hours. Serum tulobuterol levels and peak expiratory flow rate we re determined before and after each application. Results: Cmax of tulo buterol 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 t o those of adults obtained in other studies. Peak expiratory flow rate values obtained after application of HN-078 significantly increased i n comparison to those obtained before application. No significant chan ges 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 tul obuterol, HN-078, will be very useful for the treatment of pediatric a sthma. It is especially significant that no side effects were observed .