Comparative Pharmacology
Head-to-head clinical analysis: ENTADFI versus VIAGRA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENTADFI versus VIAGRA.
ENTADFI vs VIAGRA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of a 5α-reductase inhibitor (finasteride) and a phosphodiesterase 5 inhibitor (tadalafil). Finasteride inhibits type II 5α-reductase, preventing conversion of testosterone to dihydrotestosterone, reducing prostate growth. Tadalafil inhibits PDE5, increasing cGMP in smooth muscle, causing relaxation of the prostate and bladder neck.
Sildenafil inhibits phosphodiesterase type 5 (PDE5), increasing cGMP levels in corpus cavernosum, leading to smooth muscle relaxation and blood flow into the penis.
5 mg orally once daily.
50 mg orally once as needed approximately 1 hour before sexual activity; range 25-100 mg based on efficacy and tolerability. Maximum dosing frequency: once per day.
None Documented
None Documented
Finasteride: terminal half-life ~6-8 hours (range 4-12 h) in young adults, 8 hours in elderly. Tadalafil: terminal half-life ~17.5 hours (range 11-28 h), supporting once-daily dosing.
Terminal elimination half-life approximately 4 hours (range 3–5 hours). No significant accumulation with recommended dosing.
ENTADFI (finasteride 5 mg and tadalafil 5 mg) is a fixed-dose combination. Finasteride is excreted 57% in feces (as metabolites) and 39% in urine (<1% as unchanged). Tadalafil is excreted primarily as metabolites, with 61% in feces and 36% in urine; <0.001% of dose is excreted unchanged in urine.
Renal (approximately 80% as metabolites, 20% as unchanged drug in feces), biliary/fecal (about 13% unchanged in feces). Total clearance 41 L/h.
Category C
Category C
5-Alpha Reductase Inhibitor and PDE5 Inhibitor
PDE5 Inhibitor