Louisville Medicine Volume 67, Issue 2 | Page 31

MEN'S HEALTH LAB INVESTIGATIONS The diagnosis of hypogonadism should be made after two early morning total testosterone levels are less than 300. If the diagnosis of low testosterone is made, further testing should be done to identify if the cause is testicular, hypothalamic or pituitary. Testosterone is bound tightly to sex hormone binding globulin (SHBG). Free and loosely bound testosterone are called bio-available testosterone. Bio-available testosterone is a calculated value and is used more frequently than free testosterone as there is considerable variability in its measurements. Men with low testosterone levels and low LH levels need a pitu- itary MRI regardless of prolactin levels as non-secretory adenomas may be identified. Estradiol needs to be measured in men with breast tenderness or gynecomastia. It is essential to get baseline labs namely CBC, CMP and PSA levels prior to starting testosterone therapy. Subsequently, once a steady state of testosterone has been reached, the aforementioned labs and a testosterone level must be checked every six months. TREATMENT The goal of treatment is to alleviate the symptoms of hypogonad- ism, restore sexual function, libido and well-being. The goal is to attain testosterone levels between 300 and 800 during testosterone replacement. Transdermal patches Patches deliver testosterone continuously over a 24-hour period. Application site reactions account for a majority of the adverse effects associated with patches. Local reactions include pruri- tus, blistering, erythema and dermatitis. There is a significant percentage of patients that discontinue patches due to their side-effects. Topical Gels There are several brand name gels available on the market. The gels deliver 40-50 mg of testosterone daily. Androgel and Testim are applied to the shoulders and upper arms daily while Fortesta is applied to the thighs. Axiron is a liquid and applied to the axilla daily. Buccal and nasal delivery Striant is a buccal system of delivery that is used twice a day. Natesto is a nasal pump that is used every eight hours. These alternate systems have failed to obtain a significant following secondary to the more than once daily dosing. Injectables Testosterone cypionate and enanthate are the two most com- monly used formulations of injectable testosterone. Peak levels occur in 72 hours and wane over the next few weeks. There is a wider fluctuation with injectables as opposed to patches or gels. The advantage of injectable testosterone is its cost-effectiveness. It takes several weeks to fine-tune the dosage and the injection intervals to attain physiological levels of testosterone. A good starting dose is 100 mg testosterone cypionate weekly that can be titrated based on levels and alleviation of symptoms. Testosterone Pellets Testopel is an effective method of testosterone replacement. Testosterone pellets are placed subcutaneously every four to six months. Each pellet is 75 mg of testosterone, and a good starting dose is 12 pellets. Careful monitoring of testosterone levels will determine the the dosage and frequency of subse- quent Testopel insertions. Oral Testosterone Oral testosterone is not recommended for testosterone re- placement secondary to its potential for liver dysfunction on account of the first-pass metabolism. Other options Clinicians may use aromatase inhibitors, HCG, SERM (selective estrogen receptor modulators) in men with low testosterone desiring to preserve fertility. RISKS AND BENEFITS The benefits of testosterone replacement in the hypogonadal male are numerous. It improves sexual and erectile function, improves general well-being, improves responsiveness to PDE-5 inhibitors, improves exercise tolerance and decreases all-cause mortality. Clinicians need to inform patients that hypogonadism is a risk factor for cardiovascular disease. Cardiovascular benefits or harm from testosterone therapy are inconclusive. Until there is defin- itive evidence proving association between testosterone therapy and subsequent major cardiac events, the recommendation is to counsel patients that the current literature does not demonstrate an increased risk. There is no definitive evidence linking testosterone therapy to thromboembolic events or development of prostate cancer. CONCLUSION Hypogonadism is a disease process that can affect men of all ages, especially older men. For men with low testosterone levels, and signs and symptoms of hypogonadism, a wide array of treatment choices are available. Careful dosing and monitoring of lab values and symptomatology are essential in the successful treatment of these patients. All of us need to be able to recognize and treat these patients appropriately to put an end to the unscrupulous “Low T” clinics that are practicing bad medicine and to whom several innocent and naïve patients are falling prey! Dr. Rao is a practicing urologist at First Urology. JULY 2019 29