A 40-year-old man comes to the office due to erectile dysfunction and loss of libido. The patient's history is notable for Hodgkin lymphoma that was treated with chemotherapy. Physical examination is normal except for small testes. Laboratory evaluation shows consistently low total and free early morning testosterone levels and elevated serum LH. Transdermal testosterone therapy is prescribed. Which of the following should be periodically monitored during this patient's treatment?

Question

A 40-year-old man comes to the office due to erectile dysfunction and loss of libido.  The patient's history is notable for Hodgkin lymphoma that was treated with chemotherapy.  Physical examination is normal except for small testes.  Laboratory evaluation shows consistently low total and free early morning testosterone levels and elevated serum LH.  Transdermal testosterone therapy is prescribed.  Which of the following should be periodically monitored during this patient's treatment?

Quizplus · Accepted Answer

11ec160b_3bbf_cf26_9249_b56a6e15892e_MD0001_00 This patient has hypogonadism presenting with erectile dysfunction and loss of libido associated with a low serum testosterone level. Other common manifestations of hypogonadism include fatigue, loss of muscle mass, and decreased bone density. Hypogonadism is a common complication of cytotoxic chemotherapy (eg, cyclophosphamide) in long-term cancer survivors. Testosterone replacement therapy (TRT) is indicated for men with symptoms of hypogonadism and persistently low serum testosterone levels. However, testosterone has trophic effects on the prostate, mediated by conversion to dihydrotestosterone by 5-alpha reductase in local tissues. TRT is associated with increased prostate volume, a rise in serum prostate-specific antigen (PSA), and a possible increase in the risk for prostate cancer. PSA should be measured prior to initiation of therapy and periodically thereafter. In addition, TRT can induce erythrocytosis, possibly due to suppression of hepcidin and increased intestinal iron absorption. This can lead to increased blood viscosity and an elevated risk for thromboembolism. Therefore, TRT should not be initiated in patients with a baseline hematocrit >50%, and hematocrit should be followed regularly during treatment. (Choice A) Some experts believe there is an increased risk of cardiovascular events associated with TRT and patients should be advised of this possibility. However, testing (eg, ECG) in asymptomatic patients is not necessary. (Choices C and E) Patients with central/secondary hypogonadism (ie, low testosterone with low or inappropriately normal LH) should be tested for deficiencies in other hypothalamic-pituitary systems (eg, TSH + serum thyroxine, morning cortisol). However, this patient has an elevated LH level consistent with primary hypogonadism, making these additional tests unnecessary. (Choice D) Because renal toxicity is not a major concern with TRT, renal function does not need to be monitored. Educational objective: Testosterone replacement therapy is indicated for men with symptomatic hypogonadism. It is associated with an increase in serum prostate-specific antigen and may raise the risk of prostate cancer. In addition, testosterone therapy can cause erythrocytosis (leading to thromboembolism), and hematocrit should be regularly monitored. __________ References: Erythrocytosis following testosterone therapy. (http://www.ncbi.nlm.nih.gov/pubmed/28526632) Hypogonadism in male cancer patients. (http://www.ncbi.nlm.nih.gov/pubmed/22528986)

A 40-Year-Old Man Comes to the Office Due to Erectile