经典问答
【孕期用药】复方新诺明的孕期用药安全性
在孕期该药FDA的分级是C。药物的动物实验有致畸的表现,主要是腭裂。而目前没有大样本的人群试验结论。一项186例的回顾性研究发现安慰剂组先天畸形的发生率是4.5%,药物组是3.3%。文献报道有早孕期没有先天畸形的45例报道。但是由于该药影响叶酸的代谢,孕期有潜在的风险,建议收益大于风险时才考虑使用。下面是英文的资料,供参考。Pregnancy:Teratogenic Effects: Pregnancy Category C.In rats, oral doses of 533 mg/kg or 200 mg/kg produced teratologic effects manifested mainly as cleft palates.The highest dose which did not cause cleft palates in rats was 512 mg/kg sulfamethoxazoleor 192 mg/kg trimethoprim when administered separately. In two studies in rats, no teratology was observed when 512 mg/kg of sulfamethoxazole was used in combination with 128 mg/kg of trimethoprim. In one study, however, cleft palates were observed in one litter out of 9 when 355 mg/kg of sulfamethoxazole was used in combination with 88 mg/kg of trimethoprim.In some rabbit studies, an overall increase in fetal loss (dead and resorbed and malformed conceptuses) was associated with doses of trimethoprim 6 times the human therapeutic dose.While there are no large, well-controlled studies on the use of sulfamethoxazole and trimethoprim in pregnant women, Brumfitt and Pursell,9 in a retrospective study, reported the outcome of 186 pregnancies during which the mother received either placebo or sulfamethoxazole and trimethoprim. The incidence of congenital abnormalities was 4.5% (3 of 66) in those who received placebo and 3.3% (4 of 120) in those receiving sulfamethoxazole and trimethoprim. There were no abnormalities in the 10 children whose mothers received the drug during the first trimester. In a separate survey, Brumfitt and Pursell also found no congenital abnormalities in 35 children whose mothers had received oral sulfamethoxazole and trimethoprim at the time of conception or shortly thereafter.Because sulfamethoxazole and trimethoprim may interfere with folic acid metabolism, sulfamethoxazole and trimethoprim should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.