Antimicrobial Therapy during Pregnancy

임산부의 항균제 치료

Pregnancy is not associated with increased risk for infectious disease, except for urinary tract infection, chorioamnionitis, endometritis and puerperal sepsis which are results of altered physiology during pregnancy. There are several numbers of infectious diseases in which the rational antimicrobial therapy could not be delayed to the postpartum periods. The first consideration of antimicrobial therapy in pregnant woman is the physiologic change associated with the normal pregnancy; Usually the plasma volume increased with enlarged both hepatic and renal clearance of the drugs. The maternal capacity to metabolize toxic substances decreases as the gestational age increases. Few things are known about the fetal pharmacokinetics of antimicrobial agents, but that the overall contribution seems not to be considerable and the maternal serum level monitoring is enough to keep the fetus from adverse effects. The United States Food and Drug Administration (FDA) had recommended a criteria to select antimicrobial agents during pregnancy according to the known data on the fetal risks of each drugs giving a classification from A to D and X. Antimicrobial agents like penicillins, cephalosporins and erythromycin bases that belong to the class B can be safely used to treat maternal infections. Class C with no adequate human data, should not be primarily considered. But any exposure to the class C antimicrobial agents does not necessarily signify increased fetal risk so that therapeutic abortion should be considered. Even class D drug may be necessary to treat some specific infections, if the benefit is proven. The oldest antimicrobial agent penicillins with well known pharmacokinetics is safely prescribed for the treatment of syphilis and susceptible streptococcal infections. The combination regimen of ampicillin-sulbactam is safe despite known evidence of Cocms' positivity without fetal anomaly. Cephalosporins add good pharmacokinetics properties to the equivalent safety to penicillins. Methyltetrazolethiol group toxicities should be considered but related fetal toxicity is not associated. In case of metronidalzole, though potential for carcinogenesis in rodents is known, no human cancer is known till present, and many controlled study on exposed pregnant woman did not repαt increased fetal risk. Treatment of tuberculosis during pregnancy is strongly recommended to reduce the rate of neonatal transmission, congenital tuberculosis and abortion, pre-eclamps, dystorcia.