8679 Case: The Sexual, Physical and Psychological Effects of Post-Finasteride Syndrome

Abstract Disclosure: E.M. Lonergan: None. S.M. Maher: None. I. Yaseen: None. D.B. O'Shea: None. Post-finasteride syndrome (PFS) is an increasingly recognised disorder with a myriad of physical and neuropsychiatric symptoms persisting for greater than three months in a small proportion of patients treated with Finasteride. We present the case of a 45-year-old male who was taking oral Finasteride for hair loss. He first presented to endocrinology services having stopped Finasteride after twenty years reporting new onset reduced libido, penile shrinkage, fatigue, new food intolerances and agitated depression which was the predominant symptom in this case. He described the emergence of gynaecomastia, which was evident on examination, as well as muscle atrophy. Biochemistry was unremarkable including testosterone 24.6 nmol/L (8.6-29.0), oestradiol 100 pmol/L (50 – 159), LH 7.1 IU/L (1.7-8.6), FSH 16.8 IU/L (1.5-12.4), urinary free cortisol 177 nmol/24h (12-486) and urinary steroid profile. The patient was offered a trial of IM testosterone for 3 months followed by a course of hCG which he declined after discussing with patients online via a PFS patient forum citing anecdotal pseudo immune downregulation in this cohort. GLP-1 receptor agonist therapy was considered as a second-line treatment option. The patient expressed a preference for hydrocortisone treatment after conducting online research which has not been commenced due to a lack of evidence. The inhibition of 5-alpha-reductase in Finasteride-treated patients has been documented to cause reversible sexual dysfunction. However, with increasing case reports of PFS, it was included in the list of Rare and Genetic Diseases of the NIH in 2015. The syndrome encompasses symptoms and signs seen in our case, as well as erectile dysfunction, decreased ejaculatory volume, infertility, Peyronie’s disease, testicular pain, dry skin, memory problems and insomnia. Suicidal ideation was included in the product label as per FDA mandate in 2022. The literature is largely inconclusive regarding the underlying aetiology, duration, and severity of the disorder. A large retrospective study revealed 0.8% of patients developed sexual dysfunction with persistence in 33% of these cases after drug suspension, the main independent risk factor being drug treatment for longer than 7 months. Neuropsychiatric symptoms are likely related to the presence of 5-alpha-reductase isoforms in the brain with resulting alterations in CSF and plasma neuroactive steroid levels and metabolites. Evidence-based treatment options for PFS are limited. PFS is a rare but debilitating syndrome to which a subset of patients appears to be predisposed, but of which the pathophysiology is poorly understood. Further studies in this regard, as well as an exploration of effective treatment options are required. Presentation: 6/1/2024