May 23 2022

Classification of the active ingredient ketoconazole


Risk level in pregnancy: This medicine is classified as Category C.

Although it is unknown whether ketoconazole crosses the placenta in humans, it does in animals. In rats treated with this substance, the placenta showed hypertrophy, increased weight, diameter and thickness.

The oral doses up to 80 mg / kg in rats produces alterations in the fingers of the hind legs, as the absence of fingers or syndactyly. The drug has shown to be embryotoxic when administered during the first trimester of pregnancy and caused dystocia during the last phase of this.

No studies have been conducted on its use in pregnant women. Therefore, ketoconazole should not be administered during pregnancy unless the potential benefit justifies the potential risk to the fetus.

A case-control study conducted in 2005 in Hungary on pregnant patients who had taken ketoconazole during the 2nd and 3rd month of pregnancy in the period 1980 to 1996 showed no significant difference between the number of malformations of the group treated with the drug compared to the control group, and the prevalence of anomalies was very similar (0.03%).

Some authors consider that the topical use of azols to treat superficial infections is safe. Although vaginal absorption is greater than through the skin, this route of administration is likely safe, but there is no data available. However, the systemic use of these same drugs presents a dose-dependent toxic risk and there is a serious risk of fetal malformations.

Update 18.07.2009

Meaning of category C

Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.