Review of beta-lactam antibiotics in pregnancy. The need for adjustment of dosage schedules.

beta-Lactam antibiotics represent the oldest class of antibiotics used in the treatment of infections, and benzylpenicillin (penicillin G) is still the most commonly used antibiotic agent during pregnancy. There is a number of studies to suggest that the pharmacokinetics of beta-lactam antibiotics are altered during pregnancy, indicating faster elimination of these antibiotics and lowered plasma concentrations. These changes are largely related to the physiological changes taking place in the maternal body. Generally, drugs are used cautiously during pregnancy, and dosages used may sometimes be inadequate. With regards to antibiotic agents, assurance of adequate therapy by applying pharmacokinetic knowledge when dosage schedules are designed should be a major concern so that the pregnancy is protected from the hazards of infection.