The Food and Drug Administration (FDA) is advising caution when prescribing oral fluconazole (DiflucanPfizer) in pregnancy after evaluating data from a Danish study that indicated a possible increased risk of miscarriage when used to treat yeast infections.

Currently, the approved drug label states that available data does not suggest an increased risk of problems during pregnancy or fetal abnormalities when women are exposed to a single fluconazole 150mg dose to treat vaginal yeast infections. However, abnormalities at birth have been reported in pregnant women who take high doses (400–800mg/day) for longer than a single dose.

The Danish study had examined a cohort of 1,405,663 pregnancies and compared oral fluconazole-exposed pregnancies with up to 4 unexposed pregnancies matched on propensity score, maternal age, calendar year, and gestational age. Researchers measured hazard ratios (HR) for spontaneous abortion and stillbirth. They saw a significantly increased risk of spontaneous abortion associated with fluconazole exposure (HR 1.48, 95% CI: 1.23–1.77). No significant association was found between fluconazole exposure and stillbirth (HR 1.32, 95% CI: 0.82–2.14). In this study, most of the oral fluconazole use appeared to be 1 or 2 doses of 150mg. 

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The FDA is reminding healthcare professionals that the Centers for Disease Control and Prevention (CDC)’s guidelines recommend only using topical antifungals to treat pregnant women with vulvovaginal yeast infections, including for a longer duration if the infections persist or recur. Patients who are pregnant or trying to conceive should discuss with their healthcare professional about alternative options for yeast infections. 

Oral fluconazole is indicated to treat yeast infections of the vaginal area, mouth, and esophagus; to treat cryptococcal meningitis; and to prevent yeast infections that can spread to the rest of the body in cancer patients who are immunocompromised.  

The FDA is continuing to evaluate additional data and will release final conclusions and recommendations upon completing their review.

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