Common Questions
What are some options for testosterone replacement therapy?
Preparations and dosages
- Transdermal preparations. A gel formulation (25 mg/d) for androgen replacement (Androgel™) provides steady levels. Applied daily it may occasionally cause skin irritation. The transdermal patch (5mg/d), Androderm™, requires the application of one to two patches daily. Local irritation is also a possible side effect (1)
- Intramuscular injection. The starting dose in elderly men or those with bladder outlet symptoms is testosterone enanthate 50 mg IM q 14 days with titration upward based on symptoms and serum levels. The average dose is testosterone enanthate 200 mg IM q 14 days for young men and 150 mg IM q 14 days for older men. If administered by the patient, this is the least expensive option.
Contraindications and cautions
Available data indicate that testosterone replacement does not cause prostate cancer but may "unmask" it. Other potential adverse effects are gynecomastia or breast tenderness (usually self-limited), sleep apnea, water retention, and erythrocytosis. Replacement therapy with testosterone esters is only rarely associated with liver abnormalities or peliosis hepatitis, which is a known side effect of treatment with oral alkylated androgens. Growth of the prostate is expected in hypogonadal men treated with testosterone. This may cause urinary obstructive symptoms if there is pre-existing benign prostatic hypertrophy.
A recent study found that the addition of finasteride attenuated the impact of testosterone treatment on prostate size and PSA in elderly men (2).
Laboratory data
Laboratory studies at baseline should include complete blood count (CBC), chem 7, prostate-specific antigen (PSA), and fasting lipid panel. The timing of testosterone levels to monitor therapy is preparation-dependent (1). For the injectable form, levels should be measured midway between injections and fall within the mid-normal range (600 ng/dL to 700 ng/dL). For the transdermal and gel forms, a random level should be adequate for evaluating whether they are in the target range, but peak levels occur several hours after applying patches, and are less predictable for the gel.
For monitoring, check the hematocrit at 3-6 months interval for the first year and yearly thereafter (1). Check the PSA yearly, and consider prostate biopsy if any of the following occur: abnormal digital rectal examination; a PSA level above 4.0 ng per milliliter; a yearly PSA increase of 1.5 ng per milliliter or more; PSA increase of 0.75 ng per milliliter per year or more over two years.
- Rhoden EL, Morgentaler A. Risks of testosterone-replacement therapy and recommendations for monitoring. N Engl J Med 2004; 350: 482-492.
- Amory JK, Watts NB, Easley KA, Sutton PR, et al. Exogenous testosterone or testosterone with finasteride increases bone mineral density in older men with low serum testosterone. J Clin Endocrinol Metab 2004; 89: 503-510.