© The Canadian Journal of Urology™; 21(Supplement 2); June 2014
has been to reduce the risk of transfer by increasing the
concentration of testosterone beyond the traditional 1%,
so that a smaller volume of gel can be applied. Better
permeation of the product after initial applicationwould
also lessen the transfer risk. In the last 3 years, new
formulationswith higher concentrations of testosterone
in roughly half the volume of gel have been approvedby
the FDAand aremaking theirway into clinical practice.
88
An underarm solution containing 2% testosterone has
also been approved.
38
With any topical TRT, transfer can
be further limited by covering the treated skin area or
washing off residual testosterone from the skin.
Testosterone injections
Testosterone preparations delivered via intramuscular
injection are absorbed directly into the blood stream.
Testosterone cypionate and testosterone enanthate
have half-lives that allow intervals of 2 weeks between
injections (usually into the buttocks).
38
However,
there is considerable fluctuation in testosterone levels
in the interim, and these may negatively impact the
patient’s emotional stability, sexual activity, and sense
of well-being.
38
Moreover, patients may be unwilling
or unable to perform self-injection or tolerate injection
site pain. Along-acting injectable form of testosterone
undecoanate in castor oil, Aveed, recently approved
by the FDA, not available in Canada, extends the
time interval between injections to 10 weeks. A
study showed that this formulation, given to 117
hypogonadal men at baseline and at 4 weeks, safely
produced consistently therapeutic testosterone levels
during the next 10 weeks.
89
TABLE 5.
Testosterone therapy: formulations, advantages, and disadvantages
38,51,56
Formulation Standard regimen Disadvantages
Advantages
Transdermal agents
Hydroalcoholic 50-100 mg/day Risk of transfer to
Convenience; flexible dosing;
gel 1%-2% (US) = 5-10 g of gel
intimate contacts;
less skin irritation than with
gel 1% (Canada)
occasional skin irritation.
patch; less risk of transfer with
higher-potency gels; ie, 1.62%, 2%;
mimic physiologic T levels.
Skin patch
5 mg/day, applied Local irritation; urticarial.
Convenience; mimics physiologic
at bedtime
T levels and diurnal rhythm.
Underarm 60-120 mg/day Risk of transfer to intimate contacts. Mimics physiologic T levels.
T solution 2% (30 mg/pump)
Intramuscular agents
T enanthate
300 mg/3 weeks Injection site pain. Wide peaks and Long-acting relatively inexpensive
T cypionate
200 mg/2 weeks troughs in T level associated with if self-administered; flexible
mood swings.
dosing.
T undecanoate 750 mg/10 weeks Injection site pain.
Infrequent administration.
in oil (US)
Potential pulmonary emboli.
Buccal agents
30 mg bid
Unpleasant taste; oral irritation;
Mimic physiologic T levels.
(US)
twice-daily dosing.
Subcutaneous
6-12 75 mg
Invasive placement;
Infrequent administration
T pellets (US)
pellets/3-6 months risk of extrusion and
(2x-3x year).
local infection; mood
swings. Expensive.
Oral agents
T undecanoate 40-80 mg
T levels and clinical responses vary. Convenience; easily titrated.
capsules
2-3 times/day
Must be taken with meals.
with meals
Not approved in United States.
Available in Canada
T = testosterone
50
Miner ET AL.
