Which of the following is NOT true about finasteride (Proscar)?

Finasteride is known for its ability to treat conditions like benign prostatic hyperplasia (BPH) by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), which is a significant factor in prostate tissue growth. It's important to recognize that while finasteride can reduce the size of the prostate over time, this process does not happen quickly. Patients typically experience symptoms improvement and size reduction over several months of consistent treatment, making it inaccurate to state that it reduces prostate size quickly.

The other statements about finasteride are reflective of its established uses and side effects. It is primarily used for addressing urinary symptoms related to BPH, and it can indeed have side effects, including those impacting sexual function, such as decreased libido or erectile dysfunction. Additionally, finasteride is used off-label for treating male pattern baldness, as it also lowers DHT levels in the scalp, thereby helping to mitigate hair loss. Thus, A is the only statement that misrepresents the pharmacological characteristics of finasteride, as it implies an expedited effect that does not align with clinical observations.