Ambroxol versus betamethasone for the promotion of antepartum lung maturity in pathological pregnancies

: Although glucocorticoids have been universally implemented to stimulate fetal lung maturity, their effectiveness and side effects are still widely contested. In search of alternative drugs a double-blind study was conducted between June 1981 and June 1984 comparing betamethasone, a conventional corticoid, and ambroxol, a bromhexine metabolite for efficacy and tolerance in prenatal prevention of the respiratory distress syndrome (RDS) in premature infants and full-term neonates. The therapeutic efficacies of betamethasone and ambroxol for this indication proved to be comparable. Since the possible risks of corticoid therapy in abnormal pregnancies are repeatedly discussed in the literature and in daily clinical practice. 137 patients with EPH gestosis, placental insufficiency, diabetes mellitus, and premature rupture of the membranes were selected from the original group of 308 patients. Only minor side effects (e.g. nausea) were present in a few of the 137 cases undergoing treatment with the 2 test substances. No side effects were observed in the neonates. The incidence of fetal RDS was comparable in both groups (2.9% with ambroxol, 2.2% with betamethasone). Transient and mild RDS cases were slightly more frequent in the ambroxol group than in the betamethasone group. To date, contraindications to ambroxol treatment in abnormal pregnancies are unknown and since generally the rate of potential side effects is considered to be lower in comparison with corticoid treatment, the use of ambroxol especially in abnormal pregnancies corresponding indication can be recommended.