A PROSPECTIVE RANDOMIZED CLINICAL-TRIAL COMPARING A NEW ORAL SUSTAINED-RELEASE RITODRINE WITH CONVENTIONAL TABLETS

Objectives: Evaluation of maternal metabolic and cardiovascular respon ses to treatment with the new sustained-release oral ritodrine as comp ared with the conventional tablets. Method: Thirty-two pregnant patien ts who had successful intravenous tocolysis were randomly assigned to treatment with either ritodrine tablets or sustained-release capsules. After 5 days of the randomly determined first oral treatment each pat ient was shifted to the alternate ritodrine formulation for a further 5-day course. Each patient underwent metabolic and non-invasive hemody namic evaluation. Results. Echocardiographic parameters during treatme nt with ritodrine tablets were not significantly different from during sustained-release capsules. Mean systolic blood pressure increased si gnificantly during peak drug activity in patients treated with ritodri ne tablets and not during treatment with the sustained-release form. F asting plasma glucose levels were higher in patients on conventional t ablets therapy than in patients on sustained-release ritodrine therapy (88.9 +/- 9 mg/dl vs. 78.7 +/- 8 mg/dl, P < 0.05) while levels follow ing a 50-g oral glucose challenge test did not differ significantly (1 35 +/- 32 mg/dl vs. 124.5 +/- 27 mg/dl) Conclusions: Because of fewer metabolic and cardiovascular side-effects, the new oral therapy offers some advantages over the presently available tablets.