Testosterone Replacement and Hypogonadism: A Brief Review of APIs
Testosterone Replacement and Hypogonadism: A Brief Review of APIs that
Modify Testosterone’s Metabolism in the Body
Testosterone
replacement therapy is currently the standard of treatment for hypogonadism,
however, testosterone replacement alone is not always sufficient due to the
multiple metabolic pathways involved in the transformation or breakdown of
testosterone.1 Testosterone is converted to estradiol via aromatase.
Estrogens such as estradiol generate negative feedback to the hypothalamus and
pituitary gland reducing the amount of follicle stimulating hormone (FSH) and
luteinizing hormone (LH) secreted. This negative feedback loop resulting in
reduction of FSH and LH (gonadotropins) decreases testosterone production which
can compromise the utility of testosterone therapy alone for hypogonadism.1
Adjunct therapies such as aromatase inhibitors (anastrozole, letrozole etc.) or
estrogen receptor antagonists (clomiphene,
enclomiphene, tamoxifen, etc.), or GNRH antagonists
such as sermorelin are sometimes used instead of or in combination with
testosterone supplementation to prevent the negative feedback loop associated
with estradiol.1,2 One study evaluating combination treatments with
anastrozole and testosterone, concluded that anastrozole given in conjunction
with testosterone replacement therapy kept estrogen levels low and attenuated
adverse effects typically associated with elevated estrogen levels that can
occur with testosterone replacement therapy alone.3 Other studies evaluating clomiphene citrate
versus testosterone replacement therapy have noted the benefit of clomiphene
for raising testosterone levels and combating hypogonadism.4 Though
testosterone is necessary for spermatogenesis, exogenously administered
testosterone, in the form of testosterone replacement therapy, can inhibit FSH
and LH secretion by the pituitary gland, resulting in decreased
spermatogenesis.2 Studies evaluating ingredients that work to
prevent this adverse effect on spermatogenesis, including anastrozole and
clomiphene among others, have demonstrated efficacy for increasing FSH or LH
and improvements in spermatogenesis.4,5,6 To learn more about these active
pharmaceutical ingredients (APIs) as well as others used for this purpose, check
out a summary table of the listed APIs and the studied dosages and routes for
each of these ingredients on our Fagron Academy site!
The topics and descriptions discussed within this
presentation are not intended and should not be interpreted to make
recommendations or claims regarding the use, efficacy, or safety of products,
formulas, or vehicles. Only a physician or other appropriately licensed
professional, as a learned intermediary, can determine if a formula, product or
service is appropriate for a patient
Citations:
1.
Ide
V, Vanderschueren D, Antonio L. Treatment of Men with Central Hypogonadism:
Alternatives for Testosterone Replacement Therapy. Int J Mol Sci.
2020;22(1):21. Published 2020 Dec 22. doi:10.3390/ijms22010021
2. Rambhatla A, Mills JN, Rajfer J.
The Role of Estrogen Modulators in Male Hypogonadism and Infertility. Rev Urol.
2016;18(2):66-72. doi:10.3909/riu0711
3. Glaser RL, York AE. Subcutaneous
Testosterone Anastrozole Therapy in Men: Rationale, Dosing, and Levels on
Therapy. Int J Pharm Compd. 2019;23(4):325-339.
4. Dadhich P, Ramasamy R, Scovell
J, Wilken N, Lipshultz L. Testosterone versus clomiphene citrate in managing
symptoms of hypogonadism in men. Indian J Urol. 2017;33(3):236-240.
doi:10.4103/iju.IJU_372_16
5. Shoshany O, Abhyankar N,
Mufarreh N, Daniel G, Niederberger C. Outcomes of anastrozole in
oligozoospermic hypoandrogenic subfertile men. Fertil Steril.
2017;107(3):589-594. doi:10.1016/j.fertnstert.2016.11.021
6. Taylor F, Levine L. Clomiphene
citrate and testosterone gel replacement therapy for male hypogonadism:
efficacy and treatment cost. J Sex Med. 2010 Jan;7(1 Pt 1):269-76. doi:
10.1111/j.1743-6109.2009.01454.x. Epub 2009 Aug 17.
Comments
Post a Comment