Effect of application site, clothing barrier, and application site washing on testosterone transfer with a 1.62% testosterone gel

Abstract

Objectives:

To evaluate the effect of application site location, clothing barrier, and application site washing on testosterone transfer from males dosed with 1.62% testosterone gel to female partners.

Research design and methods:

Open-label, randomized, parallel group, crossover study performed in 24 healthy male/female couples. 2.5 or 5.0 g of gel was applied to upper arms and shoulders or abdomens of male subjects. Skin contact occurred 2 hours after gel application between male and female subjects to compare the effect of wearing or not wearing a t-shirt, washing or not washing before contact, and the effect of differing application sites. Treatments were separated by a 1-week washout period. On each dosing day, 15 minutes of supervised skin contact occurred between the dosed male and female partner. Contact was either abdomen to abdomen (male to female), or upper arms/shoulders (male) to upper arms/shoulders, wrists and hands (female), depending on the male application site. Serum samples were collected from females at baseline and after contact to assess secondary testosterone exposure.

Main outcome measures:

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

Results:

Testosterone exposure (C_av and C_max) in females increased by up to 27% (2.5 g) or up to 280% (5.0 g) from baseline after direct skin contact at 2 hours after gel application, although C_av remained within the female eugonadal range. Transfer from the abdomen was prevented when a t-shirt was worn (2.5-g dose). When the application site was washed before contact, mean C_av was comparable to baseline, and C_max was slightly higher (14%). Transfer was higher after direct skin-to-skin contact when the application and contact sites were upper arms/shoulders versus the abdomen. Testosterone concentrations returned to baseline within 48 hours after last skin contact.

Conclusions:

There is a risk of testosterone transfer from males using 1.62% testosterone gel to others who come into direct skin contact with the application site. This can be prevented by covering the application site with a t-shirt (2.5-g dose), or washing the application site before contact.

Study limitations:

Women for these studies were not selected by menopausal status. The study was conducted under circumstances that were intended to simulate exaggerated conditions of contact and may not represent average contact under normal conditions.

Clinical Trial Registration NCT Numbers:

Study was not registered (first subject enrolled 28 November 2007)

Key words::

• 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. Jr. and S.F. were employees of Abbott at the time of the study. M.B. is an employee of Quintiles, Inc., which performed the statistical analysis and prepared the clinical study report.

Acknowledgments

The authors would like to thank Janet Benesh for assistance in the design, implementation, oversight, and analysis of the results of this study. Medical writing support for preparation of this paper was provided by Robin Smith, PhD, of The Curry Rockefeller Group, LLC., Tarrytown, NY. Funding for this support was provided by Abbott.

Material in this paper has been previously presented as a poster at: 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