FINASTERIDE TAB
Clinical Criteria Summary
Criteria for Combination Alpha-Blocker and Finasteride Therapy for BPH
- Indicated for clinical progression of BPH symptoms defined by:
- Increase in AUA symptom score ≥4 points from baseline
- History of acute urinary retention
- Indicated for persistently bothersome symptoms despite adequate alpha-blocker therapy
- Requires large prostate (typically >40ml, or approximately the size of a golf ball)
- For patients not previously treated with alpha-blockers: requires baseline AUA score ≥12 and high risk for intervention or urinary retention due to large prostate volume
- Patients must be on maintenance doses (or highest tolerated dose if maintenance was not achieved)
- Finasteride is not recommended for prevention of prostate cancer based on the Prostate Cancer Prevention Trial due to increased incidence of higher-grade tumors (Gleason scores 7-10)
- Risks and benefits of long-term finasteride therapy must be discussed with the patient; patients should be reevaluated regularly
- Referral to a local expert is strongly advised for patients with severe unrelenting symptoms, very large prostates, or smaller prostate mass with poor response to alpha-blockers
Criteria for Specific Alpha-Blocker Monotherapy Maintenance Doses
- Alfuzosin: 10 mg qd
- Doxazosin: 8 mg qd (monotherapy) or titrated to a maximum of 8 mg/day (MTOPS study context)
- Prazosin: 4 mg BID
- Terazosin: 10 mg qd
- Tamsulosin: 0.4 mg qd
Safety Criteria
- Alpha-blockers (including doxazosin and other non-selective alpha-blockers): dizziness, postural hypotension, and asthenia (may limit titration)
- Finasteride: erectile dysfunction, decreased libido, or abnormal ejaculation
- Combination therapy: abnormal ejaculation, peripheral edema, and dyspnea occur more frequently; breast cancer was diagnosed in four men receiving finasteride (monotherapy or combination)
- Finasteride reduces PSA levels; after >6 months of therapy, PSA levels may be doubled to approximate actual off-therapy levels
Drug Interaction Criteria (Alpha-Blockers with PDE5 Inhibitors)
- Sildenafil: Symptomatic hypotension noted with doxazosin 4mg. Do not take sildenafil 50mg or 100mg within 4 hours of an alpha-blocker; 25mg may be taken at any time.
- Tadalafil: Significant augmentation of BP lowering effect noted with doxazosin 8mg. Concomitant administration with an alpha-blocker other than tamsulosin is not recommended.
- Vardenafil: Significant hypotension (standing SBP < 85 mm Hg) noted with terazosin and simultaneous/post-dose tamsulosin. Concomitant administration of vardenafil with an alpha-blocker is contraindicated.