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
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.
Intramuscular injection
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
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.
Transdermal Vehicle
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 |