1. ¹Division of Urology, Mount Sinai Hospital and Women's College Hospital, University of Toronto, Toronto, ON, Canada
2. ²Scott Department of Urology, Baylor College of Medicine, Houston, TX, USA

Correspondence: Dr ED Grober, Division of Urology, Mount Sinai Hospital and Women's College Hospital, University of Toronto, Murray Koffler Urologic Wellness Centre, 60 Murray Street, 6th Floor, Box 19, Toronto, ON, Canada M5T 3L9. E-mail: ethan.grober@utoronto.ca

Received 24 July 2007; Revised 30 August 2007; Accepted 31 August 2007; Published online 27 September 2007.

Abstract

The study objective was to evaluate the efficacy of changing testosterone gel preparations among suboptimally responsive hypogonadal men. The records of all hypogonadal men on gel (Testim or Androgel) testosterone replacement therapy (TRT) were reviewed to identify men who underwent a brand substitution in gel TRT due to initial suboptimal response. Total and free serum testosterone levels and the presence of hypogonadal symptoms (ADAM) were compared pre- and post-gel substitution. Of the 370 hypogonadal men on testosterone gel replacement therapy, 75 (20%) underwent a brand substitution. Prior to substitution, among patients initially treated with Androgel, the mean total and free testosterone levels were 311 ng dl^-1 and 10.4 pg ml^-1, respectively. Total testosterone levels were below 300 ng dl^-1 in 58% of these patients. Following a change to Testim, mean total and free testosterone levels increased to 484 ng dl^-1 (P<0.001) and 14.6 pg ml^-1 (P=0.01), respectively. Total testosterone levels remained below 300 ng dl^-1 in only 17% of these patients. Among patients initially treated with Testim, the mean total and free testosterone levels were 544 ng dl^-1 and 18.0 pg ml^-1, respectively. Total testosterone levels were below 300 ng dl^-1 in 15% of men. Following testosterone gel change to Androgel, mean total and free testosterone levels were 522 ng dl^-1 (P=0.7) and 16.1 pg ml^-1 (P=0.6), respectively. Total testosterone levels remained below 300 ng dl^-1 in 27% of these patients. Hypogonadal symptoms improved in a significant proportion of men who underwent a brand substitution following an initial suboptimal biochemical or symptomatic response. A change in testosterone gel preparation among initially unresponsive hypogonadal men is justified prior to abandoning or considering more invasive TRT. Changing from Androgel to Testim offers hypogonadal men the potential for improved clinical and biochemical responsiveness. Changing from Testim to Androgel is indicated to eliminate or minimize unwanted side effects.