Introduction To Male Testosterone
Types of Testosterone Replacement Therapy
Ideal testosterone replacement therapy produces and maintains physiologic serum concentrations of the hormone and its active metabolites without significant side effects or safety concerns. Several different types of testosterone replacement are currently marketed, including tablets, injectables, sublingual, transdermal, and Pellet insertion.
Oral agents may cause elevations in liver function tests and abnormalities at liver scan and biopsy. Both modified and unmodified oral testosterone preparations are available. Unmodified testosterone is rapidly absorbed by the liver, making satisfactory serum concentrations difficult to achieve. Modified 17-alpha alkyltestosterones, such as methyltestosterone or fluoxymesterone, also require relatively large doses that must be taken several times a day.
Testosterone cypionate and enanthate are frequently used parenteral preparations that provide a safe means of hormone replacement in hypogonadal men. In men 20-50 years of age, an intramuscular injection of 200 to 300 mg testosterone enanthate is generally sufficient to produce serum testosterone levels that are supranormal initially and fall into the normal ranges over the next 14 days. Fluctuations in testosterone levels may yield variations in libido, sexual function, energy, and mood. Some patients may be inconvenienced by the need for frequent testosterone injections.1Increasing the dose to 300 to 400 mg may allow for maintenance of eugonadal levels of serum testosterone for up to three weeks, but higher doses will not lengthen the eugonadal period.2
Sublingual testosterone is placed under the tongue and is usally in the form of a square or circle, depending on strength of troche. A sublingual dose is given twice a day, same as the transdermal therapy below. It by-passes the liver and takes about 2 to 3 minutes to melt. The taste is generally bitter but the compounding pharmacies will flavor it to mask the bitterness somewhat. Testosterone levels will peak and drop on this therapy, this is why it would be best to take it two or three times a day in smaller doses.
Clinical studies of transdermal systems demonstrate their efficacy in providing adequate testosterone replacement therapy.3,4 Transdermal therapy can be made in a cream or gel by a compounding pharmacy. Different strengths are used, ranging from 10mg to 200mg per ml. A daily dose is given in the early morning hours. For best results of maintaining physiologic testosterone levels you would want to take testosterone twice a day early am (5am to 7am) and again around (1 to 4pm).
Monitoring Patients on Testosterone Replacement