New boxed warning for testosterone gels

Testosterone gel is used frequently to treat male hypogonadism. In 2007, 1.4 million prescriptions of Androgel 1% and 370,000 prescriptions of Testim 1% were dispensed. Patients using testosterone gel are advised to wash their hands and cover treated skin with clothing to avoid exposing others.

Despite these precautions, the FDA received reports of eight cases of children with secondary exposure to testosterone. The ages ranged from 9 months to 5 years. The adverse events included inappropriate enlargement of the genitalia, premature development of pubic hair, advanced bone age, increased libido and aggressive behavior. In most cases, the users of these products did not follow instructions, and there was direct contact between the treated skin and the child.

The signs and symptoms regressed after exposure was stopped in most cases. However, in a few cases, the bone age remained greater than the child’s age, and enlarged genitalia did not return to age-appropriate size. At least one child underwent surgery due to a delay in determining the underlying cause.

Because of these reports, the FDA will require manufacturers of Androgel 1% and Testim 1% to include a boxed warning on the products’ labels. The label changes provide additional information about the risk of secondary exposure and measures to reduce this risk.

Eight cases is not a large number. However, I suspect there may be more cases than we realize. Last year a pediatric endocrinologist informed me about a case she had seen in her practice. The child had virilization without known cause. A thorough endocrine evaluation was negative. However, the father had been using testosterone gel. No known direct exposure had taken place. The father was adamant that he always washed his hands and avoided direct contact with treated skin and his child. Nevertheless, without any other explanation for the symptoms, we both assumed that the child had been exposed to the testosterone gel in some way.

I will continue to use testosterone gel when treating male hypogonadism. I have always advised my patients to take precautions to avoid exposing others and review the application technique at follow-up visits. Now, I more strongly remind them about the potential risk of exposing others and steps to minimize this.

For more information:

FDA News Release: “Testosterone Gel Safety Concerns Prompt FDA to Require Label Changes, Medication Guide.” May 7, 2009. http://www.fda.gov/bbs/topics/NEWS/2009/NEW02011.html