孕妇用药分级与禁忌药品介绍.pptVIP

孕婦用藥分級與禁忌藥品介紹及鼓勵藥物不良反應通報案 前言 懷孕前期吃了藥，就要考慮拿掉孩子 ? 懷孕期間不管怎麼樣都不能服用藥物 ? Rate of Medication use during pregnancy: data from the Avon Longitudinal Study of Parents and Children. 11,545 women Only 7.6% used no medicinal product throughout their entire pregnancy. 92.4% used at least one product at some stage. Analgesics:1/3 women Antacids were reported by 23%. Antibiotic use decreased slightly during pregnancy from 8% early on to 5.8% at 32 weeks. Amoxicillin was the most frequently reported antibiotic. (B級) Class outline for today Pharmacokinetics of pregnant women Drug selection during pregnancy Teratogenic drugs Pharmacokinetics of pregnant women Pregnancy physiology v.s. PK (pharmacokinetics) GI activity changed →(absorption) Cardiovascular system →(distribution) -- plasma volume expansion -- increase in cardiac output -- regional blood flow changed Decrease in albumin concentration →(distribution) Enzyme activity changed →(metabolism) Increase in GFR →(elimination) GI activity changed Decrease gastric acidity Delay in gastric emptying ? Alter drug absorption Cardiovascular system  Plasma volume expansion -- begins at 6-8 wks of gestation -- volume of 4700 – 5200 ml -- peaks at 32 wks of gestation -- 40%: maternal compartment 60% amniotic fluid,placenta,fetus Cardiac output -- increase 30-50 % -- 50% by 8 wks of gestation Cardiovascular system Regional blood flow changed -- increase blood flow to uterus ( 20% of cardiac output) -- increase renal blood flow -- increase skin blood flow -- increase mammary blood flow -- decrease skeletal muscle blood flow Albumin level Decrease in albumin concentration ? free form of drugs increased Enzyme activity changed Related to pregnancy hormonal changes Estrogen can cause cholestasis → Drugs excreted into the biliary system ↓ Progesterone → inhibit N-demethylation CYP 3A4 : increase activity during pregnancy Hepatic metabolism ? en