This Article Full Text Full Text (PDF) All Versions of this Article: 90/5/2610    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Amory, J. K. Articles by Bremner, W. J. Search for Related Content PubMed PubMed Citation Articles by Amory, J. K. Articles by Bremner, W. J. Related Collections Male Endocrinology

Oral Testosterone in Oil Plus Dutasteride in Men: A Pharmacokinetic Study

Center for Research in Reproduction and Contraception, Divisions of General Internal Medicine and Endocrinology, Metabolism, and Nutrition, University of Washington Medical School, Seattle, Washington 98195

Address all correspondence and requests for reprints to: Dr. John K. Amory, University of Washington, Box 356429, 1959 NE Pacific Street, Seattle, Washington 98195. E-mail: jamory{at}u.washington.edu.

Testosterone (T) is not administered orally, because it has been reported to be rapidly metabolized by the liver. We hypothesized that sufficient doses of T or T enanthate (TE), administered orally in oil, would result in clinically useful elevations in serum T. We also hypothesized that coadministration of dutasteride (D) with T or TE would minimize increases in serum DHT seen previously with oral administration. Therefore, we conducted a pharmacokinetic study of oral T and TE in oil, with and without concomitant D, in normal men whose T production had been temporarily suppressed by the GnRH antagonist acyline. Thirteen healthy men (mean age, 24 ± 6 yr) were enrolled and assigned to oral T (n = 7) and oral TE (n = 6) groups and were administered 200, 400, or 800 mg of either T or TE in sesame oil in the morning on 3 successive days 24 h after receiving acyline. Blood samples for measurement of serum T and dihydrotestosterone were obtained before T or TE administration and 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 h after administration. Subjects were then administered D for 4 d before repeating the sequence of T or TE doses with D. Serum T was significantly increased in a dose-dependent fashion with the administration of oral T or TE in oil. Coadministration of D with oral T or TE significantly increased the 24-hr average serum T levels compared with administration of T or TE alone [average serum T after 400 mg dose, 8.7 ± 3.0 nmol/l (T) and 8.3 ± 5.7 nmol/l (TE) vs. 16.1 ± 5.8 nmol/l (T +D) and 15.0 ± 8.8 nmol/l (TE + D); P < 0.05 for T vs. T and D]. The administration of oral T or TE in oil combined with D results in unexpected and potentially therapeutic increases in serum T. Additional studies of this combination as a novel form of oral androgen therapy are warranted.

This article has been cited by other articles:

				J. K. Amory, T. F. Kalhorn, and S. T. Page Pharmacokinetics and Pharmacodynamics of Oral Testosterone Enanthate Plus Dutasteride for 4 Weeks in Normal Men: Implications for Male Hormonal Contraception J Androl, May 1, 2008; 29(3): 260 - 271. [Abstract] [Full Text] [PDF]

				S. T. Page, W. J. Bremner, R. V. Clark, M. A. Bush, H. Zhi, R. B. Caricofe, P. M. Smith, and J. K. Amory Nanomilled Oral Testosterone Plus Dutasteride Effectively Normalizes Serum Testosterone in Normal Men With Induced Hypogonadism J Androl, March 1, 2008; 29(2): 222 - 227. [Abstract] [Full Text] [PDF]

				J. K. Amory, S. T. Page, and W. J. Bremner Oral Testosterone in Oil: Pharmacokinetic Effects of 5{alpha} Reduction by Finasteride or Dutasteride and Food Intake in Men J Androl, January 1, 2006; 27(1): 72 - 78. [Abstract] [Full Text] [PDF]