Comparative Pharmacology
Head-to-head clinical analysis: TADALAFIL versus VIAGRA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TADALAFIL versus VIAGRA.
TADALAFIL vs VIAGRA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Inhibitor of phosphodiesterase type 5 (PDE5), enhancing cyclic guanosine monophosphate (cGMP)-mediated relaxation of smooth muscle in the corpus cavernosum and pulmonary vasculature.
Sildenafil inhibits phosphodiesterase type 5 (PDE5), increasing cGMP levels in corpus cavernosum, leading to smooth muscle relaxation and blood flow into the penis.
Erectile dysfunction: 10-20 mg orally as needed, 30-60 minutes before sexual activity; maximum 1 dose per day. Benign prostatic hyperplasia: 5 mg orally once daily. Pulmonary arterial hypertension: 40 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
Clinical Note
moderateTadalafil + Torasemide
"Tadalafil may increase the antihypertensive activities of Torasemide."
Clinical Note
moderateTadalafil + Travoprost
"Tadalafil may increase the antihypertensive activities of Travoprost."
Clinical Note
moderateTadalafil + Unoprostone
"Tadalafil may increase the antihypertensive activities of Unoprostone."
Clinical Note
moderateTadalafil + Hydrochlorothiazide
"Tadalafil may increase the antihypertensive activities of Hydrochlorothiazide."
Terminal elimination half-life is 17.5 hours in healthy subjects; supports once-daily dosing and prolonged effect (up to 36 hours for erectile function).
Terminal elimination half-life approximately 4 hours (range 3–5 hours). No significant accumulation with recommended dosing.
Primarily hepatic metabolism (CYP3A4); 36% excreted in urine (mainly metabolites), 61% in feces (mainly metabolites), <0.1% 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 A/B
Category C
PDE5 Inhibitor
PDE5 Inhibitor