What is the Optimal Form of Testosterone for Replacement Therapy?
Testosterone USP is natural testosterone that has been approved by the United States Pharmacopoeia and is available as a bulk chemical. Upon a prescription order, compounding pharmacists can use Testosterone USP to compound numerous dosage forms. The information that follows should be considered as prescriber, patient, and pharmacist work together to meet the specific needs of each patient.
A healthy adult male secretes 8-15mg/day of testosterone. This “physiologic dose” should be considered when prescribing replacement therapy. Excessive dose leading to high serum levels of testosterone can result in a greater conversion to estradiol (and side-effects resulting from abnormally high estradiol levels), because the body can not effectively store excess testosterone. This may be a reason to administer testosterone on a daily basis, rather than using long-lasting injections.
Testosterone is well-absorbed from trans dermal (topical) creams and gels. Dosage forms also include sublingual drops, buccal or sublingual troches, or table triturates. These offer excellent alternatives to oral Testosterone USP tablets, because testosterone that is absorbed through the gastrointestinal tract passes directly into the blood vessels supplying the liver, where the drug is significantly inactivated.
Compounded preparations can be very advantageous. For example, there is no need to shave the area to apply trans dermal testosterone preparations. The medication can be administered as a single dose (rather than multiple patches), and there is no skin irritation from patch adhesive. The cream or gel can be applied two or three time daily to simulate the normal circadian rhythm.
In the form know as Testosterone Cypionate, testosterone can be administered by intra muscular injection every 1-3 weeks. However, release may vary widely from patient to patient, resulting in significant fluctuation in serum testosterone levels. Polycythemia, a serious blood disorder, is more common with 10-14 day regimens.
The only absolute contraindications to androgen replacement therapy are the presences of prostate or breast cancer. Although it is know that the clinical course of prostate cancer is accelerated by testosterone, its clear evidence that testosterone replacement accelerated the development of BHP.
Natural testosterone must not be confused with synthetic derivatives or ”anabolic steroids,” which when used by athletes and body builders have caused disastrous effects, including heart problems and cancer. The term “testosterone” is often used generically when referring to numerous synthetic derivatives, as well as natural testosterone. The confusion surrounding testosterone transcends the lay person; it is responsible for conflicting data in the medical literature about the benefits and risks of testosterone therapy. Studies must be reviewed carefully to determine the form of testosterone that was used. For example, administration of synthetic non-aromatizable androgens, like stanozolol or methyl testosterone, causes profound decrease in HDL-C9”good cholesterol”) and significant increase in LDL(“bad cholesterol”), and has associated with serious heart disease. Yet, hormone replacement with testosterone, an aromatizable androgen, results in lower total cholesterol and LDL cholesterol levels while having little to no impact no serum HDL cholesterol levels. In the doses needed for male hormone replacement, methyl testosterone cause a rise in liver enzymes and cholesterol, peliosis of the liver, and liver toxicity, and is not recommended.