Bicalutamide for Female Pattern Hair Loss: Should we add it to the list of anti androgens ?

Bicalutamide (Casodex) is pure anti-androgen with Potential Benefit in Treating Female Androgenetic Alopecia

Bicalutamide is a non-steroidal pure anti androgen that was FDA approved for treating prostate cancer at a dose of 50 mg daily back in 1995. Recent studies have investigated its use in treating female androgenetic alopecia.

STUDY 1: Ismail and colleagues, 2020

Dr. Rodney Sinclair’s group from Australia (Ismail and colleagues, 2020) performed a retrospective review of 316 women treated with bicalutamide. The standard starting dose was 10 mg daily although starting doses ranged from 5 mg to 50 mg in the study. The average age of patients was 49 years with a range of 15-85 years. In the study bicalutamide was usually prescribed together with some other medication including oral minoxidil in 308 patients and spironolactone in 172 patients. Six patients received bicalutamide alone (i.e. monotherapy). The most common adverse effect was mild elevation of liver transaminases in 9 (2.85%) patients. This elevation was mild in all cases (less than twice the upper limit of normal) and asymptomatic in all cases as well.. Furthermore, the liver enzyme elevation resolved without needing to adjust the dose in 4 out of 9 patients. In 2 patients, the transaminitis resolved with further dose reduction. Other side effects bicalutamide in the study included peripheral edema in 2.5 % of patients and gastrointestinal complaints in 1.9 %. Use of bicalutamide provided benefit in the treatment of AGA in women.

STUDY 2: Fernandez-Nieto and colleagues, 2020

Dr. Sergio Vano Galvan’s group from Spain (Fernandez-Nieto et al. 2020) recently published their data of 44 women receiving bicalutamide at doses of 25-50 mg daily. The ages of patients in this study were 20-59 with an average age of 34.8 years. The authors chose higher doses than Sinclair’s group for the simple reason that higher doses of bicalutamide are already commonly used in treating hirsutism. Side effects in this particular study included transient elevation in liver enzymes with 5 of 44 (11.4%) patients having a mild increase liver enzymes - all of which self resolved without a need to stop the drug. In addition to elevated liver enzymes, other reported side effects including were shedding, amenorrhea, headaches and endometrial hyperplasia. None of the patients needed to stop treatment. Similar to the Ismail et al study mentioned above, use of bicalutamide in this study also provided benefit in the treatment of AGA in women.

COMMENTS

These are interesting studies and I suspect we’ll be hearing a lot more about bicalutamide in the years to come. I’ve been using it for a few years now and was encouraged to see some good data here with regard to side effect profile and generally good safety. Bicalutamide has fewer side effects than flutamide, another non stereoidal anti androgen (NSAA) and in general the side effects profile is acceptable when compared to the 2 other commonly used antiandrogens we use for treating androgenetic alopecia - spironolactone and finasteride. Further studies are needed to understand how bicalutamide compares to finasteride and spironolactone and what of side effects we might need to counsel our female patients.

Reference

Ismail et al. Safety of oral bicalutamide in female pattern hair loss: a retrospective review of 316 patients. Journal of the American Academy of Dermatology. Available online 19 April 2020

Fernadez-Nieto Et al. BICALUTAMIDE: A POTENTIAL NEW ORAL ANTIANDROGENIC DRUG FOR FEMALE PATTERN HAIR LOSS.J Am Acad Dermatol. 2020 Apr 19:S0190-9622(20)30667-8. doi: 10.1016/j.jaad.2020.04.054. Online ahead of print.