Comparative Pharmacology
Head-to-head clinical analysis: ENTADFI versus STENDRA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENTADFI versus STENDRA.
ENTADFI vs STENDRA
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.
Selective inhibitor of phosphodiesterase type 5 (PDE5), enhancing cyclic guanosine monophosphate (cGMP) accumulation in corpus cavernosum, leading to smooth muscle relaxation and increased penile blood flow.
5 mg orally once daily.
50 mg orally once daily as needed, 1 hour before sexual activity. Maximum dose 100 mg. Maximum frequency once daily.
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 is approximately 4 hours in healthy subjects; may be prolonged in hepatic impairment (Child-Pugh B: up to 6 hours) or with concomitant CYP3A4 inhibitors.
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.
Fecal (approximately 63%) and renal (approximately 21%) as metabolites; less than 2% excreted unchanged in urine.
Category C
Category C
5-Alpha Reductase Inhibitor and PDE5 Inhibitor
PDE5 Inhibitor