[Hemodynamic changes during tocolysis with hexoprenaline and fenoterol].

Area of Science:

• Obstetrics and Gynecology
• Pharmacology

Background:

• Premature labor is a significant concern in obstetrics.
• Beta-mimetics are commonly used tocolytic agents to suppress uterine contractions.
• Comparing the efficacy and side effect profiles of different beta-mimetics is crucial for optimizing treatment.

Purpose of the Study:

• To compare the hemodynamic effects and efficacy of Hexoprenaline versus Fenoterol in patients experiencing premature labor.
• To evaluate the impact of these beta-mimetics on heart rate, cardiac output, stroke volume, and diuresis.

Main Methods:

• A comparative study involving two groups of 50 patients each, receiving Hexoprenaline or Fenoterol (with Verapamil) for premature labor.
• Hemodynamic parameters including heart rate, stroke volume (impedance cardiography), cardiac output, and total peripheral resistance were monitored.
• Uterine contractility, urine elimination, and osmolarity were also assessed.

Main Results:

• Equipotent doses (Hexoprenaline/Fenoterol ratio 1:8) showed a slower and smaller heart rate increase with Hexoprenaline over 24 hours.
• Both drugs demonstrated identical suppression of uterine contractility.
• Hexoprenaline resulted in lower inhibition of diuresis compared to Fenoterol, potentially due to differential beta-receptor activity.

Conclusions:

• Hexoprenaline may offer a more favorable hemodynamic profile with less cardiac stimulation compared to Fenoterol for managing premature labor.
• The observed differences in diuresis inhibition suggest varying interactions with beta-1 and beta-2 receptors.
• Further research into receptor specificity could refine the use of beta-mimetics in tocolysis.