A comparative study between nifedipine and isoxsuprine in the suppression of preterm labour.

Preterm labour and delivery remains a major cause of perinatal morbidity and mortality. Numerous drugs and interventions have been used to prevent and inhibit preterm labour but none have been found to be completely effective with the choice being further limited by troublesome side effects. This study compares in a prospective and randomised design the efficacy and safety of the calcium antagonist Nifedipine with the beta mimetic Isoxsuprine. 81.25% of patients receiving Nifedipine and 70% of those receiving Isoxsuprine achieved successful tocolysis. The mean prolongation of pregnancy with Nifedipine was 25+/-19.85 days and with Isoxsuprine it was 19.18+/-17.82 days. Maternal side effects were similar in both groups with hypotension and tachycardia being the commonest. Discontinuation rates were also similar with pulmonary oedema and severe hypotension being the reasons for foregoing tocolysis. It can be concluded that Nifedipine is a safe and effective alternative to Isoxsuprine for suppressing preterm labour.