Occurrence of Convulsions after Administration of Theophylline in a Large Japanese Pediatric Population with Asthma

Abstract

The main objective of this study was to evaluate the incidence of convulsions in a large Japanese pediatric population (60,634 patients from 79 centers) treated with theophylline (T). Moreover, further details were obtained from the affected patients. Two sequential questionnaires were sent to centers in order to obtain data. The incidence rate of convulsions was 0.24% (127/54,066) in asthmatic patients treated with T vs. 0.36% (27/7,568) in asthmatic patients not treated with T (p = NS). Eight patients showed convulsions related to T treatment: this group included three infants≤1 year, high mean serum T concentration at the time of convulsion attack (16.7 ± 1.6 μg/mL), and high concomitant medication rate. The rate of recurrent convulsions after readministration of theophylline was higher for patients with epilepsy than for patients with febrile convulsions. In conclusion, the incidence of convulsions in pediatric patients was not affected by the use of theophylline as treatment for asthma. The low frequency of side effects related to convulsions suggest theophylline treatment is safe, but special care must be taken with the following: pyrexia, dose control in infants <1 year, combined ways of drug administration (i.e., oral and suppository), and use of concomitant drugs (antihistamines or macrolides).