Once or twice daily theophylline in childhood asthma

We conducted a randomized, single-blind, crossover trial to compare two sustained release theophylline preparations. Fifty-nine chronic asthmatics, aged 7-14 years, were randomly allocated to receive Slophyllin (SP) twice daily followed by Uniphyllin (UP) taken as a single dose at bedtime, or UP followed by SP. Two 4-week periods on therapeutic doses of each preparation were compared. Thirty-six patients completed the study. Eight were non-compliant, seven defaulted and eight withdrew because of theophylline related side-effects (seven on UP). Symptom scores, beta-agonist usage, compliance by pill counts, evening peak flow rates and maximal expiratory flow-volume curves were similar on both treatments. Blood levels of theophylline at 11 am and morning peak flow rates were significantly higher on UP. UP may be more helpful for patients with early morning symptoms, but is associated with an increased frequency of severe side effects.