From the FDA Drug Label
In patients with chronic renal impairment, with creatinine clearances ranging from 9.0 to 55 mL/min, AUC, maximum plasma concentration, half-life, and protein binding after a single dose of 14C-finasteride were similar to values obtained in healthy volunteers. No dosage adjustment is necessary in patients with renal impairment. No dosage adjustment is necessary in patients with renal impairment [see CLINICAL PHARMACOLOGY (12.3)] .
Finasteride can be used in patients with Chronic Kidney Disease (CKD), as no dosage adjustment is necessary in patients with renal impairment. However, it is essential to note that urinary excretion of metabolites was decreased in patients with renal impairment, and plasma concentrations of metabolites were significantly higher in patients with renal impairment 1 1.
From the Research
Finasteride can be safely used in patients with Chronic Kidney Disease (CKD) without dose adjustments, as it is primarily metabolized by the liver with minimal renal excretion, making it suitable for patients with reduced kidney function. The medication works by inhibiting the enzyme 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT), thereby reducing prostate size in BPH or promoting hair regrowth in baldness 2. Standard dosing applies: 5mg daily for benign prostatic hyperplasia (BPH) or 1mg daily for male pattern baldness. While no specific dose modifications are needed for CKD patients, it's essential to monitor for potential side effects such as sexual dysfunction, decreased libido, and gynecomastia, which can occur regardless of kidney function.
Some studies have highlighted the importance of careful medication management in CKD patients to prevent further kidney damage, emphasizing the need to avoid nephrotoxic drugs 3, 4. However, finasteride is not classified as a nephrotoxic drug, and its use in CKD patients does not require special precautions regarding kidney function. For patients on dialysis, no additional adjustments are necessary as the drug is minimally removed during dialysis procedures. As with any medication in CKD patients, monitoring for unexpected adverse effects is recommended, particularly when starting therapy.
The most recent and highest quality study on the topic, published in 2022, suggests that finasteride may even have beneficial effects on CKD progression by inhibiting trimethylamine N-oxide synthesis and regulating gut microbiota 2. This study provides new insights into the potential therapeutic effects of finasteride in CKD patients, further supporting its safe use in this population.
Key points to consider when prescribing finasteride to CKD patients include:
- Monitoring for potential side effects such as sexual dysfunction, decreased libido, and gynecomastia
- Standard dosing applies: 5mg daily for BPH or 1mg daily for male pattern baldness
- No dose adjustments are needed for CKD patients
- Finasteride is not a nephrotoxic drug and does not require special precautions regarding kidney function
- Monitoring for unexpected adverse effects is recommended, particularly when starting therapy.