Comparative Pharmacology
Head-to-head clinical analysis: FINASTERIDE AND TADALAFIL versus VIAGRA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FINASTERIDE AND TADALAFIL versus VIAGRA.
FINASTERIDE AND TADALAFIL vs VIAGRA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Finasteride is a 5α-reductase inhibitor that inhibits conversion of testosterone to dihydrotestosterone (DHT). Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor that enhances nitric oxide-mediated vasodilation by increasing cyclic guanosine monophosphate (cGMP) in smooth muscle.
Sildenafil inhibits phosphodiesterase type 5 (PDE5), increasing cGMP levels in corpus cavernosum, leading to smooth muscle relaxation and blood flow into the penis.
One capsule containing finasteride 5 mg and tadalafil 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: 6-8 hours (elderly ~8 hours); Tadalafil: 17.5 hours (enables once-daily dosing).
Terminal elimination half-life approximately 4 hours (range 3–5 hours). No significant accumulation with recommended dosing.
Finasteride: 57% feces, 39% urine (metabolites); Tadalafil: 36% urine, 61% feces (mostly metabolites).
Renal (approximately 80% as metabolites, 20% as unchanged drug in feces), biliary/fecal (about 13% unchanged in feces). Total clearance 41 L/h.
Category A/B
Category C
PDE5 Inhibitor
PDE5 Inhibitor