Pregnancy is a state of flux with the placental-fetal unit undergoing constant changes that affect both pharmacodynamics and pharmacokinetics of many drugs. Pregnancy affects hepatic biotransformation in an enzyme-specific manner. Increased cardiac output, tissue flow, and vasodilatation during pregnancy may enhance absorption of drugs administered subcutaneously, intramuscularly, epidurally, transvaginally, and via mucous membranes. The treatment of drug overdose in pregnancy presents a unique challenge because of changes in the pharmacodynamics and pharmacokinetics of drugs during gravid state. The most frequently used agents for self-inflicted poisoning during pregnancy are analgesics, antipyretics, and antirheumatics. The treatment of acetaminophen overdose is aimed at decreasing the absorption of acetaminophen and protecting the hepatocytes from the toxic effects of the highly reactive metabolites. The therapeutic approach in carbon monoxide poisoning is to deliver high-dose oxygen to displace carbon monoxide from the hemoglobin molecule.