Physiologic changes in pregnancy and their effect on drug disposition

Area of Science:

• Pharmacology
• Obstetrics
• Physiology

Background:

• Maternal physiological adaptations during pregnancy can impact drug pharmacokinetics.
• These changes include alterations in fluid balance, protein binding, acid-base status, cardiac output, renal function, hepatic metabolism, and gastrointestinal motility.

Purpose of the Study:

• To outline the significant physiological changes occurring during pregnancy, labor, and postpartum.
• To emphasize the implications of these changes on drug pharmacokinetics in pregnant women.

Main Methods:

• Review of physiological changes during pregnancy, intrapartum, and postpartum periods.
• Analysis of how these physiological alterations affect drug absorption, distribution, metabolism, and excretion.

Main Results:

• Pregnancy involves substantial physiological shifts, including expanded plasma volume, altered protein concentrations, respiratory alkalosis, increased cardiac output, enhanced renal blood flow, modified hepatic enzyme activity, and changed gastrointestinal function.
• These changes commence early in gestation, are most prominent in the third trimester, and continue through the postpartum period.

Conclusions:

• The dynamic physiological landscape of pregnancy necessitates a thorough understanding of pharmacokinetic alterations.
• Pharmacokinetic studies in pregnant populations are essential for optimizing drug therapy and ensuring maternal and fetal safety.