Serum testosterone levels in non-dosed females after secondary exposure to 1.62% testosterone gel: effects of clothing barrier on testosterone absorption

Abstract

Objective:

To evaluate secondary exposure of testosterone transferred to females from a male partner, dosed with 1.62% testosterone gel after direct skin-to-skin contact with the application site, and to investigate the effect of wearing a t-shirt on testosterone transfer.

Research design and methods:

Across three studies, a total of 72 healthy males applied 5.0 g 1.62% testosterone gel to their abdomen alone, upper arms/shoulders alone, or a combination of their upper arms/shoulders and abdomen (single dose or once daily for 7 days). Male–female contact occurred 2 or 12 hours after testosterone gel application, with males either wearing or not wearing a t-shirt. There were 15 minutes of supervised contact with the application site between the male and his female partner. Blood samples were collected over a 24 hour period in females for assessment of serum testosterone levels at baseline and after contact.

Main outcome measures:

Pharmacokinetic parameters included C_max (maximum serum concentration), AUC_0–24 (area under the serum concentration–time curve from 0–24 hours), and C_av (time-averaged concentration over the 24-hour period post-contact). Subjects were monitored for adverse events.

Clinical trial registration NCT numbers:

Study 1 was not registered (first subject enrolled 8 March 2007); Study 2: 00998933; Study 3, 01130298.

Results:

Testosterone levels (C_av and C_max) in females increased 86–185% from baseline after direct abdominal skin contact, although C_av levels remained within female eugonadal range. Testosterone concentrations returned to baseline within 48 hours after last skin contact. A t-shirt barrier reduced testosterone transfer by approximately 40–48% when 5.0 g of testosterone gel was applied to the abdomen alone. A t-shirt barrier prevented transfer when 5.0 g of testosterone gel was applied to the upper arms and shoulders or to a combination of the upper arms and shoulders and the abdomen (C_max and C_av increased by approximately 5–11%). No major safety events were observed during the studies.

Conclusions:

There is a risk of testosterone transfer from males using 1.62% testosterone gel to others who come in contact with the application site for at least 12 hours after application. Secondary exposure can be mitigated by means of a t-shirt barrier.

Study limitations:

Women for these studies were not selected by menopausal status. The study designs were intended to simulate exaggerated conditions of transfer.

Keywords::

• Hypogonadism
• Pharmacokinetics
• Replacement
• Testosterone
• Transfer potential

Transparency

Declaration of funding

This study was funded by Abbott.

Declaration of financial/other relationships

T.L.Z. and J.J.B. are employed by Abbott and own Abbott stock. J.S., C.McW., S.A.T., and S.F. were employees of Abbott at the time of the study. M.B. is an employee of Quintiles Inc., which performed some of the statistical analyses and preparation of the clinical study reports.

Acknowledgments

Medical writing support for preparation of this paper was provided by Robin Smith PhD, of The Curry Rockefeller Group, LLC, Tarrytown, NY, USA. Funding for this support was provided by Abbott.

Material in this paper was presented in a poster at ENDO 2011, The 93rd Annual Meeting of the Endocrine Society June 4–7, 2011, Boston, MA, USA.

Notes

*AndroGel is a registered trade name of Abbott, Abbott Park, IL, USA.