Let’s do a little update on bicalutamide. 

WPATH SOC8 recommends against, “Given that bicalutamide has not been adequately studied in trans feminine populations, we do not recommend its routine use”. I have always been pretty “pro” bica because prescribing a diuretic to a patient population that has limited and traumatic access to public restrooms is cruel.

Prior to a recent 10/2023 publication, I constructed the following prescribing guidelines for myself utilizing a dose of 50mg by mouth twice a week:

• Under the age of 40
• No significant health conditions that might affect liver resiliency
• No other hepatotoxic medications
• No significant substance use, recommended abstinence from ETOH and acetaminophen
• Baseline and continued AST/ALT within expected range of laboratory values
• Recommended holding bicalutamide when ill or planning drinking

My guidelines were informed by the following references and my clinical experience:

• Yun GY, Kim SH, Kim SW, et al. Atypical onset of bicalutamide-induced liver injury. World J Gastroenterol. 2016;22(15):4062-4065. doi:10.3748/wjg.v22.i15.4062
• Fernandez-Nieto D, Saceda-Corralo D, Jimenez-Cauhe J, et al. Bicalutamide: A potential new oral antiandrogenic drug for female pattern hair loss. J Am Acad Dermatol. 2020;83(5):e355-e356. doi:10.1016/j.jaad.2020.04.054
• Neyman A, Fuqua JS, Eugster EA. Bicalutamide as an Androgen Blocker With Secondary Effect of Promoting Feminization in Male-to-Female Transgender Adolescents. J Adolesc Health. 2019;64(4):544-546. doi:10.1016/j.jadohealth.2018.10.296
• Wadhwa VK, Weston R, Parr NJ. Bicalutamide monotherapy preserves bone mineral density, muscle strength and has significant health-related quality of life benefits for osteoporotic men with prostate cancer. BJU Int. 2011;107(12):1923-1929. doi:10.1111/j.1464-410X.2010.09726.x
• Hussain S, Haidar A, Bloom RE, Zayouna N, Piper MH, Jafri SM. Bicalutamide-induced hepatotoxicity: A rare adverse effect. Am J Case Rep. 2014;15:266-270. Published 2014 Jun 20. doi:10.12659/AJCR.890679
• Helga M. Gretarsdottir, Elin Bjornsdottir, Einar S. Bjornsson; Bicalutamide-Associated Acute Liver Injury and Migratory Arthralgia: A Rare but Clinically Important Adverse Effect. Case Rep Gastroenterol 3 September 2018; 12 (2): 266–270. https://doi.org/10.1159/000485175
• Ismail FF, Meah N, Trindade de Carvalho L, Bhoyrul B, Wall D, Sinclair R. Safety of oral bicalutamide in female pattern hair loss: A retrospective review of 316 patients. J Am Acad Dermatol. 2020;83(5):1478-1479. doi:10.1016/j.jaad.2020.03.034

There was a recent publication in October 2023 that reported on a 17 year old transgirl with what is presumed bicalutamide induced hepatic injury requiring hospitalization after 3 months of bicalutamide therapy at 50mg daily.  

Wilde B, Diamond JB, Laborda TJ, Frank L, O'Gorman MA, Kocolas I. Bicalutamide-Induced Hepatotoxicity in a Transgender Male-to-Female Adolescent. J Adolesc Health. 2024 Jan;74(1):202-204. doi: 10.1016/j.jadohealth.2023.08.024. Epub 2023 Oct 4. PMID: 37791922.    

Three poster presentations in 2023 had safety data on bicalutamide in trans patients:

• Improving Access to Bicalutamide in Gender Affirming Medical Care, Bambilla A, Beal C, Vigil P
• Bicalutamide use as antiandrogen in trans feminine adults – a safety profile; Vierregger K, Tetzlaff M, Zimmerman B, Dunn N, Finney N, Lewis K, Slomoff R, Strutner S; Department of  Internal Medicine, University of California, Irvine
• Assessment of liver function and toxicity in transgender female adolescents prescribed bicalutamide; Burgener K, Herrick C, Wallendorf M, Lewis C, DeBosch B

To date my synthesis of this information is changing a few things in my prescribing recommendations. 

• I am starting (and tapering) to 25mg twice a week.
• I am reiterating signs and symptoms of bicalutamide induced hepatic injury and counseling immediate medication cessation and emergency services. 
• I am re-emphasizing holding bicalutamide if a patient has a cold, other illness, or planned substance use. 
• I am using a teach back to confirm patient understanding.
• I am getting more aggressive about tapering off of bicalutamide once testosterone levels are well suppressed by estradiol and progesterone therapy.

 I do want to acknowledge the language of the 2023 paper male-to-female is not considered affirming by many of us. I would have recommended a title such as, "Bicalutamide Induced Hepatic Injury in Gender Affirming Care." Additionally, I wrote the author with some additional questions:

• Was the patient evaluated with serial testing for EBV/CMV/HIV after discharge? All three virus frequently test falsly negative if tested too early.
• Were baseline chemistries ever obtained from her previous medical records which were unavailable at the time of hospitalization?
• Was more information on her acetaminophen use available? Dose? Frequency? Most recent use?
• Why the bicalutamide was added in addition to the spironolactone?