The post-finasteride syndrome: possible etiological mechanisms and symptoms

Finasteride and dutasteride, synthetic 5 & alpha;-reductase inhibitors (5ARIs) are recommended in many guidelines for the treatment of benign prostatic hyperplasia/lower urinary tract symptoms and alopecia despite a variety of side effects like sexual, neurological, psychiatric, endocrinological, metabolic and ophthalmological dysfunctions and the increased incidence of high grade prostate cancer. The sexual side effects are common during the use of the drug but in a small subgroup of patients, they can persist after stopping the drug. This so-called post-finasteride syndrome has serious implications for the quality of life without a clear etiology or therapy. Three types of 5 & alpha;-reductases are present in many organs in- and outside the brain where they can be blocked by the two 5ARIs. There is increasing evidence that 5ARIs not only inhibit the conversion of testosterone to 5 & alpha;-dihydrotestosterone (DHT) in the prostate and the scalp but also in many other tissues. The lipophilic 5ARIs can pass the blood-brain barrier and might block many other neurosteroids in the brain with changes in the neurochemistry and impaired neurogenesis. Further research and therapeutic innovations are urgently needed that might cure or relieve these side effects. More awareness is needed for physicians to outweigh these health risks against the benefits of 5ARIs.

Automated summary

Finasteride and dutasteride, 5α-reductase inhibitors, are commonly used for benign prostatic hyperplasia/lower urinary tract symptoms and alopecia, but have various side effects. These side effects include sexual dysfunction, neurological disorders, psychiatric disorders, endocrine disorders, metabolic disorders, and ophthalmological dysfunctions, as well as an increased risk of high-grade prostate cancer. The drugs can also cause persistent sexual side effects in a small subgroup of patients after discontinuation, known as post-finasteride syndrome. Further research and therapeutic innovations are needed to address these side effects, and physicians need to be more aware of the potential risks.