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 1 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 (p¼0.1). 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 50;100 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.
