STABLE TESTOSTERONE LEVELS ACHIEVED
WITH SUBCUTANEOUS TESTOSTERONE
INJECTIONS
M.B. Greenspan, C.M. Chang
Division of Urology, Department of Surgery, McMaster University,
Hamilton, ON, Canada
Objectives: The preferred technique of androgen replacement
has been intramuscular (IM) testosterone, but wide
variations in testosterone levels are often seen. Subcutaneous
(SC) testosterone injection is a novel approach; however,
its physiological effects are unclear. We therefore investigated
the sustainability of stable testosterone levels using
SC therapy. Patients and methods: Between May and
September 2005, we conducted a small pilot study involving
10 male patients with symptomatic late-onset hypogonadism.
Every patient had been stable on TE 200 mg IM for
41 year. Patients were instructed to self-inject with
testosterone enanthate (TE) 100 mg SC (DELATESTRYL
200 mg/cc, Theramed Corp, Canada) into the anterior
abdomen once weekly. Some patients were down-titrated
to 50 mg based on their total testosterone (T) at 4 weeks.
Informed consent was obtained as SC testosterone administration
is not officially approved by Health Canada. T
levels were measured before and 24 hours after injection
during weeks 1, 2, 3, and 4, and 96 hours after injection
in week 6 and 8. At week 12, PSA, CBC, and T levels
were measured however; the week 12 data are still being
collected. Results: Prior to initiation of SC therapy, T
was 19.14+3.48 nmol/l, hemoglobin 15.8+1.3 g/dl, hematocrit
0.47+0.02, and PSA 1.05+0.65 ng/ml. During
the first 4 weeks, there was a steady increase in
pre-injection T from 19.14+3.48 to 23.89+9.15 nmol/l
(p0.1). However, after 8 weeks the post-injection T
(25.77+7.67 nmol/l) remained similar to that of week 1
(27.46+12.91 nmol/l). Patients tolerated this therapy with
no adverse effects. Conclusions: A once-week SC injection
of 50100 mg of TE appears to achieve sustainable and
stable levels of physiological T. This technique offers
fewer physician visits and the use of smaller quantity of
medication, thus lower costs. However, the long term
clinical and physiological effects of this therapy need further
evaluation.
