Rectal administration of theophylline in aqueous solution.

Theophylline has a narrow therapeutic index which complicates rapid effective administration. Therapeutic serum levels without toxic concentrations can usually be achieved only by a 20 min intravenous administration. In the present study 20 children were given a single dose of theophyllinne in aqueous solution rectally. Serum theophylline levels were determined, and they equalled those found after a 20 min intravenous infusion of theophylline. No adverse effects were observed. The variations in peak serum levels were the same as those reported after intravenous administration. Therefore rectal administration of an aqueous solution of theophylline may become a valuable alternative to the intravenous route. The procedure is simple, can be used at home by the parents even in cases of nausea and vomiting, and an accurate dosage calculated in mg/kg is possible. This treatment, however, cannot be recommended until further investigations have been carried out.