From the Guidelines
For benign prostatic hyperplasia (BPH), the recommended dose of finasteride is 5 mg taken once daily, while for androgenetic alopecia (male pattern baldness), the recommended dose is 1 mg once daily. Both dosages should be taken consistently at approximately the same time each day, with or without food. Patients should understand that finasteride works by inhibiting the enzyme 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT), a hormone that contributes to prostate enlargement and hair loss in genetically susceptible individuals. For BPH, symptom improvement may take 3-6 months of continuous use, while hair regrowth results typically require at least 3-4 months, with optimal results seen after 1-2 years of treatment. It's essential to note that finasteride must be taken continuously, as stopping treatment will result in reversal of benefits within 12 months. Side effects may include decreased libido, erectile dysfunction, and ejaculatory disorders in a small percentage of men, as reported in studies such as 1 and 1. Women who are pregnant or may become pregnant should not handle crushed tablets due to potential risks to male fetuses.
Some key points to consider when prescribing finasteride include:
- The reduction of DHT in prostate tissues has been measured at approximately 80% with finasteride, as noted in 1.
- Finasteride is ineffective for relief of lower urinary tract obstructive symptoms in patients who do not have enlarged prostates, as stated in 1 and 1.
- The new 5 alpha-reductase inhibitor dutasteride has been shown to be of similar efficacy as finasteride in terms of symptom score and flow-rate improvement, as well as in the prevention of disease progression, while having a comparable safety profile, as reported in 1.
- Until additional information is available, finasteride should be given for 7 years if used for primary prevention, as recommended in 1 and 1.
Overall, finasteride is a effective treatment option for BPH and androgenetic alopecia, with a recommended dose of 5 mg once daily for BPH and 1 mg once daily for androgenetic alopecia, as supported by the evidence from 1, 1, 1, 1, 1, and 1.
From the FDA Drug Label
Finasteride tablets may be administered with or without meals. 2.1 Monotherapy The recommended dose of finasteride tablet is one tablet (5 mg) taken once a day [see CLINICAL STUDIES (14.1)]. 2.2 Combination with Alpha-Blocker The recommended dose of finasteride tablet is one tablet (5 mg) taken once a day in combination with the alpha-blocker doxazosin [see CLINICAL STUDIES (14.2)].
The recommended dose and frequency of finasteride for benign prostatic hyperplasia (BPH) is one tablet (5 mg) taken once a day. For androgenetic alopecia, the dose is 1 mg taken once a day, however this information is not present in the provided drug labels. 2
From the Research
Finasteride Dosage and Frequency
- The recommended dosage of finasteride for benign prostatic hyperplasia (BPH) is 5 mg once a day 3.
- For androgenetic alopecia, the recommended dosage is 1 mg once a day 4, 5.
- Reducing the daily dose of finasteride from 5 mg to 2.5 mg in men with BPH may not significantly affect subjective and objective measures of urinary obstruction, but may result in a statistically significant increase in PSA levels 6.
Treatment Efficacy and Safety
- Finasteride has been shown to be effective in treating BPH, with improvements in urinary flow and symptoms, and a reduction in prostate size 3, 7.
- Finasteride has also been shown to be effective in treating androgenetic alopecia, with 85% of patients stopping hair loss when given the drug 7.
- Common side effects of finasteride include impotence, decreased libido, and decreased ejaculatory volume 3, 7.
Special Considerations
- Men taking finasteride for BPH or androgenetic alopecia may require adjustments to their PSA levels when undergoing prostate cancer screening 4.
- Finasteride may be used to treat other conditions, such as acne, facial hirsutism, and prostate cancer, but its use in these conditions remains investigational 3.