The patient tells you that he sees himself as a man, he wants to be called Jeff, and he prefers male pronouns. You explain that you believe he has gender dysphoria and would benefit from hormone therapy, but it is important to confirm this diagnosis with an MHP. You explain that testosterone can be prescribed for masculinizing effects, and describe the expected effects—more facial and body hair, a deeper voice, and greater muscle mass, among others—and review the likely time frame.
You also discuss the risks of masculinizing hormones (hyperlipidemia, cardiovascular disease, diabetes, and loss of bone density) that will need to be monitored. Before he leaves, you give him the name of an MHP who is experienced in transgender care and tell him to make a follow-up appointment with you after he has seen her. At the conclusion of the visit, you make a note of the patient’s name and gender identity in the chart and inform the staff of the changes.
MALE-TO-FEMALE TRANSITION
CASE 2 Before heading into your office to talk to a new patient named Carl S, you glance at his chart and see that he is a healthy 21-year-old who has come in for a routine physical. When you enter the room, you find Carl wearing a dress, heels, and make-up. After confirming that you have the right patient, you ask, “What is your current gender identity?” “Female,” says Carl, who indicates that she now goes by Carol. The patient has no medical problems, surgical history, or significant family history but reports that she has been taking spironolactone and estrogen for the past three years. Carol also says she has a new female partner and is having unprotected sexual activity.
Feminizing hormone treatment
The desired effects of feminizing hormones include voice change, decreased hair growth, breast growth, body fat redistribution, decreased muscle mass, skin softening, decreased oiliness of skin and hair, and a decrease in spontaneous erections, testicular volume, and sperm production.10,11 The onset of feminizing effects ranges from one month to one year and the expected maximum effect occurs anywhere between three months and five years.10,11 Regimens usually include anti-androgen agents and estrogen.13,26-28
The medications that have been most studied with anti-androgenic effects include spironolactone and 5-α reductase inhibitors (5-ARIs) such as finasteride. Spironolactone inhibits testosterone secretion and inhibits androgen binding to androgen receptors; 5-ARIs block the conversion of testosterone to 5-α-dihydrotestosterone, the more active form.
Estrogen can be administered via oral, sublingual, transdermal, or intramuscular route, but parenteral formulations are preferred to avoid first-pass metabolism. The serum estradiol target is similar to the mean daily level of premenopausal women (< 200 pg/mL) and the level of testosterone should be in the normal female range (< 55 ng/dL).13,26-28
The selection of medications should be individualized for each patient. Comorbidities must be considered, as well as the risk for adverse effects, which include venous thromboembolism, elevated liver enzymes, breast cancer, cardiovascular disease, diabetes, hyperprolactinemia, weight gain, gallstones, cerebrovascular disease, and severe migraine headaches.10,11 Estrogen therapy is not reported to induce hypertrophy or premalignant changes in the prostate.33 As is the case for masculinizing hormones, feminizing hormone therapy should be continued indefinitely for long-term effects.
Frequent monitoring is recommended. Patients taking feminizing hormones (transwomen) should be seen every two to three months in the first year and monitored once or twice a year thereafter. Serum testosterone and estradiol levels should initially be monitored every three months; serum electrolytes, specifically potassium, should be monitored every two to three months in the first year until stable.