Minoxidil, a popular over-the-counter hair loss treatment, is under increased scrutiny due to potential risks to infants and links to eye disorders. Recent reports have highlighted unintended exposure in infants and a growing body of evidence connecting the drug, particularly finasteride, to ocular surface abnormalities.

Infant Exposure and Hypertrichosis

The European Medicines Agency (EMA) has updated the safety leaflets for minoxidil-containing medications to include warnings about the risk of excessive hair growth in infants, a condition known as hypertrichosis or "werewolf syndrome". This decision followed reports of eleven babies developing this condition after being exposed to minoxidil through their caregivers.

The Navarra Pharmacovigilance Center in Spain investigated cases where infants developed excessive hair growth on their backs, legs, and thighs. The investigation revealed that the fathers of these infants were using topical 5% minoxidil for hair loss. The center suggested that the contact between parents using minoxidil and their babies could occur through skin-to-skin transfer or oral exposure, such as infants sucking on contaminated objects. Young children's skin is more permeable, making them more susceptible to absorbing topically administered medications. Once the exposure was eliminated, the hypertrichosis was reversible within months. Minoxidil medications are typically applied to the skin as liquids or foams, working by widening blood vessels to increase blood flow and stimulate hair growth.

Ocular Side Effects

Besides the risks to infants, research indicates a potential link between hair loss drugs, especially finasteride, and eye disorders. A study presented at the ARVO 2022 conference found an association between finasteride usage and meibomian gland dysfunction (MGD), as well as conjunctival and corneal abnormalities. The study involved a retrospective chart review of 116 patients with dry eye disease (DED) who were taking finasteride. Over a mean follow-up period of 55.3 months, a significantly greater percentage of patients presented with MGD, conjunctival abnormalities, and corneal abnormalities during follow-up exams compared to initial exams.

Researchers noted that androgen-sensitive meibomian glands might be altered in individuals taking anti-androgen medications like finasteride. These findings suggest that the long-term effects of anti-androgenic finasteride should be carefully considered before prescribing it to patients, especially those with pre-existing dry eye.

Recommendations and Warnings

In light of these findings, health authorities recommend that individuals using topical minoxidil take precautions to prevent accidental exposure to infants. This includes avoiding contact between treated areas and young children. Responsible use of minoxidil and adherence to updated package insert warnings are crucial. While minoxidil is available over the counter, consulting a doctor before use is advisable to ensure its appropriate and safe application.

The U.S. Food and Drug Administration (FDA) has been contacted for comment regarding the potential risks to American babies.