Update on the Teratogenicity of Efavirenz

In March 2005, Bristol-Myers Squibb and the FDAnotified healthcare professionals of revisions of theprescribing information for efavirenz. The pregnancycategory for the drug has changed from category C(risk of fetal harm cannot be ruled out) to categoryD (positive evidence of fetal risk). This change is aresult of four retrospective reports of neural tubedefects in infants born to women with first-trimesterexposure to efavirenz, including three cases of meningomyeloceleand one Dandy Walker syndrome.As efavirenz may cause fetal harm when administeredduring the first trimester to a pregnant woman,pregnancy should be avoided in women receivingefavirenz.