Comparative Pharmacology
Head-to-head clinical analysis: ENTADFI versus SILDENAFIL CITRATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENTADFI versus SILDENAFIL CITRATE.
ENTADFI vs SILDENAFIL CITRATE
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 citrate inhibits phosphodiesterase type 5 (PDE5) in the corpus cavernosum, increasing cGMP levels and enhancing nitric oxide-mediated smooth muscle relaxation, leading to penile erection. It also inhibits PDE5 in pulmonary vasculature, causing vasodilation and reducing pulmonary artery pressure.
5 mg orally once daily.
50 mg orally 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 3-5 hours; clinical effect duration shorter due to distribution.
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.
Approximately 80% fecal, 13% renal as metabolites; <1% unchanged in urine.
Category C
Category A/B
5-Alpha Reductase Inhibitor and PDE5 Inhibitor
PDE5 Inhibitor