Uterine motility after post-partum application of sulprostone and other oxytocics.

UNLABELLED: With the introduction of prostaglandins to obstetrics another group of substances was known to influence uterine motility also post partum. It was interesting to study the effect of equal doses of synthetic prostaglandin E2 (sulprostone), methergin and synthetic oxytocin on the so-called puerperal model in humans. By transcervically introduced twin-catheters uterine motility was recorded after uncomplicated pregnancy and delivery in 101 volunteers. Uterine motility was recorded and evaluated according to the onset of the effect, its duration, motility pattern and uterine activity. Maternal heart-rate was additionally recorded similarly to the feto-maternal cardiotocogram. All substances were applied by intramuscular injection. The following observations could be made: 1. Onset: sulprostone is effective in the shortest time, followed by oxytocin and methergin. 2. DURATION: the most prolonged effect is noticed with methergin, followed by sulprostone and syntocinon. 3. Motility pattern: the strongest effect can be seen with sulprostone, followed by methergin and syntocinon. 4. Increase of uterine motility was highest with sulprostone, followed by methergin and oxytocin. 5. No side-effects on the maternal heart-rate could be found with any of the tested substances. As a conclusion, sulprostone is recommended in the treatment of severe bleeding post partum when an immediate and long-lasting effect is to be achieved with one single substance.

[The efficacy of oral betamimetics using an oxytocin-stimulated puerperal model (author's transl)]. / Uber die Wirksamkeit oral applizierter Betamimetika am oxytocinstimulierten puerperalen Modell.

Puerperal uteri were stimulated by oxytocin, the uterine motility was recorded by transcervical catheter techniques, maternal pulse and blood-pressure were recorded continuously or intermittently. Oral tocolytics as Gynipral (Hexoprenaline), Partusisten (Fenoterol), Spiropent (Clenbuterol) and Prepar (Ritodrine) were administered orally in single or double dose. The inhibitory effect of these drugs were recorded, evaluated from the records and calculated statistically concerning their significant differences. It could be demonstrated that only Hexoprenaline in a three time higher dose than used usually and Partusisten in a dose of 10 and 20 mg were able to reduce uterine motility for more than 50%. All other substances definitely had an inhibitory effect on the puerperal uterus, but inhibition was not stronger than 30%. Cardiovascular side-effects were discussed. The question, if oral given betamimetics are effective in the treatment of threatening premature labour could not be answered definitively, but there are doubts according this study concerning the dose and the repetition of it for this purpose.