Beta-adrenoceptor tocolysis and effects on the heart of fetus and neonate. A review.

A literature of 92 scientific papers addressing the effects of beta-adrenoceptor stimulation on the heart have been collected with the support of a computer-based MEDLINE system and critically examined. Neither in animal experiments nor in a wide clinical use of tocolytics for more than two decades has a risk for the hearts of fetus and neonate been confirmed, because there is no or only very little stimulating action on the beta-adrenoceptors of fetal and newborn's hearts as their sympathetic innervation is still immature.

[Maternal plasma concentrations in multiple oral fenoterol treatment].

Reports on the clinical effectiveness of oral treatment with beta-sympathomimetic fenoterol are quite divergent in their conclusions. The aim of this study was to determine the plasma levels of fenoterol in steady state during tocolytic treatment with high oral doses. Nine pregnant women with clinically indicated tocolysis were given a 5 mg dose of fenoterol in tablet form eight times per day at prescribed hours.

[Tocolysis with fenoterol suppositories--a comparison with oral administration of fenoterol tablets].

A new application form of fenoterol (Partusisten) as 15 mg suppositories from Boehringer Ingelheim was tested for its tocolytic effect, tolerance and the main side effects under usual clinical conditions in a prospective study in 50 pregnant patients with premature labour in 24-36th week of gestation. During one week's treatment 25 pregnant women received 3 to 4 15 mg fenoterol suppositories and 25 patients 6 to 8 5 mg fenoterol tablets. Beginning on the second day of treatment until the end of therapy in both groups a reduction of the uterine activity of at least 50 percent was achieved.

[Oral tocolytic therapy with clenbuterol--clinical facts].

Clenbuterol is a betamimetic agent with a marked effect on the adrenergic beta-2-receptors relevant for tocolysis. The influence on beta-1-receptors of the heart, resulting in cardiovascular side effects is far less. The substance is resorbed almost completely enterally and has a half-life of 34 hours.