Are finasteride (Propecia) symptoms reversible?

From the Guidelines

Most finasteride symptoms are reversible after stopping the medication. According to the 2003 AUA guideline on management of benign prostatic hyperplasia 1, reported adverse events of finasteride are primarily sexually related, including decreased libido, ejaculatory dysfunction, and erectile dysfunction, and are reversible and uncommon after the first year of therapy. The guideline states that patients will generally experience a 3-point improvement in the AUA Symptom Index with finasteride, and this level of symptom improvement is perceived as a meaningful change.

Some key points to consider when evaluating the reversibility of finasteride symptoms include:

• The majority of men who develop side effects find that these issues resolve within weeks to months after discontinuation
• A small subset of patients may report persistent symptoms, such as Post-Finasteride Syndrome (PFS), although the exact prevalence and biological mechanism of PFS are unclear
• Finasteride works by inhibiting the enzyme 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT), and some theories suggest that persistent symptoms may relate to lasting changes in neurosteroid production or androgen receptor sensitivity
• Patients experiencing troublesome side effects while taking finasteride should consult their healthcare provider before stopping the medication to discuss their symptoms and explore alternative treatments for hair loss or prostate conditions, as noted in the guideline 1.

Overall, while some patients may experience persistent symptoms, the available evidence suggests that most finasteride symptoms are reversible 1.

From the FDA Drug Label

In sexually mature male rats treated with 61 times the human exposure (80 mg/kg/day), there were no significant effects on fertility after 6 or 12 weeks of treatment; however, when treatment was continued for up to 24 or 30 weeks, there was an apparent decrease in fertility, fecundity and an associated significant decrease in the weights of the seminal vesicles and prostate All these effects were reversible within 6 weeks of discontinuation of treatment. The following additional adverse events have been reported in postmarketing experience with finasteride tablets Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: - sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, decreased libido and ejaculation disorders (e. g. reduced ejaculate volume). Normalization or improvement of poor seminal quality has been reported after discontinuation of finasteride.

Reversibility of Finasteride Symptoms: The effects of finasteride on fertility in rats were reversible within 6 weeks of discontinuation of treatment 2. However, sexual dysfunction that continued after discontinuation of treatment has been reported in postmarketing experience with finasteride tablets, including erectile dysfunction, decreased libido, and ejaculation disorders 2. Additionally, normalization or improvement of poor seminal quality has been reported after discontinuation of finasteride 2. It is essential to note that the independent role of finasteride in these events is unknown. Therefore, while some effects of finasteride may be reversible, the reversibility of all symptoms is not guaranteed, and the causal relationship to drug exposure is not always established.

From the Research

Finasteride Symptoms Reversibility

• The reversibility of finasteride symptoms is a topic of ongoing research and debate 3, 4, 5, 6, 7.
• Some studies suggest that finasteride has been associated with reversible adverse sexual side effects in multiple randomized, controlled trials for the treatment of male pattern hair loss (MPHL) 3.
• However, other studies have reported persistent sexual side effects in men who took finasteride for MPHL, with symptoms persisting for at least 3 months despite discontinuation of the medication 3, 5, 6.
• A study found that 96% of subjects with persistent sexual side effects associated with finasteride continued to experience these symptoms after 9-16 months, suggesting that the dysfunction may be permanent 5.
• The concept of "post-finasteride syndrome" has been proposed to describe the constellation of persistent sexual, neuropsychiatric, and physical symptoms that may occur in some men after taking finasteride 4, 7.

Persistent Sexual Side Effects

• Studies have reported a range of persistent sexual side effects associated with finasteride, including low libido, erectile dysfunction, decreased arousal, and problems with orgasm 3, 5, 6.
• The duration of these symptoms can vary, with some men experiencing persistent sexual dysfunction for many months or years after discontinuing finasteride 5.
• The mechanisms underlying these persistent sexual side effects are not fully understood and require further research 7.

Clinical Implications

• Physicians treating MPHL should discuss the potential risk of persistent sexual side effects associated with finasteride with their patients 3.
• The use of 5α-reductase inhibitors in patients with a history of depression, sexual dysfunction, or infertility should be carefully and individually assessed 4.
• Further research is needed to understand the pathophysiological mechanisms underlying post-finasteride syndrome and to develop effective treatments for this condition 7.