From the Guidelines
Pregnant healthcare providers should avoid direct contact with 5-fluorouracil (5-FU) cream due to potential risks to the developing fetus. This topical chemotherapy medication, used to treat conditions like actinic keratosis and superficial skin cancers, is classified as a pregnancy category X drug, meaning it has demonstrated fetal harm in studies, as outlined in the U.S. FDA Categories for Drugs Used in Pregnancy table 1. When applying 5-FU cream to patients, pregnant healthcare providers should use protective measures including:
- Nitrile gloves (double-gloving is recommended)
- Disposable gowns
- Careful handwashing after removal of protective equipment The concern stems from 5-FU's mechanism as an antimetabolite that interferes with DNA synthesis, which could theoretically affect rapidly dividing fetal cells if absorbed through the skin. While the risk of significant systemic absorption through intact skin is relatively low with proper protection, the potential consequences warrant these precautions. Ideally, pregnant healthcare providers should consider having non-pregnant colleagues handle 5-FU application when possible to eliminate any potential risk. According to the FDA categories, category X drugs like 5-FU have demonstrated positive evidence of fetal abnormalities, and their use is contraindicated in women who are or may become pregnant 1.
From the FDA Drug Label
Fluorouracil cream may cause fetal harm when administered to a pregnant woman. Fluorouracil administered parenterally has been shown to be teratogenic in mice, rats, and hamsters when given at doses equivalent to the usual human intravenous dose; however, the amount of fluorouracil absorbed systemically after topical administration to actinic keratoses is minimal
The amount of fluorouracil absorbed systemically after topical administration is minimal. However, there is no direct information in the label about the risk to a pregnant doctor applying the cream.
- The label discusses the risk of fetal harm when the cream is administered to a pregnant woman, not when applied by a pregnant woman.
- The label does not provide information on the safety of the doctor applying the cream if they are pregnant. The FDA drug label does not answer the question.
From the Research
Harmful Effects of 5-FU Cream on Pregnant Doctors
- There is no direct evidence in the provided studies to suggest that 5-FU cream is harmful to doctors applying it if they are pregnant 2, 3, 4, 5, 6.
- The studies primarily focus on the effects of 5-FU on patients undergoing treatment for cancer, as well as its pharmacogenomics and resistance mechanisms.
- However, it is known that 5-FU is a chemotherapeutic agent that can have toxic effects on the body, and it is possible that exposure to 5-FU cream could pose a risk to pregnant individuals 2.
- Further research would be needed to determine the specific risks associated with 5-FU cream exposure in pregnant doctors.
Mechanism of Action of 5-FU
- 5-FU works as an antimetabolite to prevent cell proliferation, primarily inhibiting the enzyme thymidylate synthase and blocking thymidine formation required for DNA synthesis 2.
- This mechanism of action could potentially pose a risk to pregnant individuals, as it may affect fetal cell development.
- However, the provided studies do not specifically address the risks associated with 5-FU cream exposure in pregnant doctors.