Comparative Pharmacology
Head-to-head clinical analysis: REVATIO versus VIAGRA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: REVATIO versus VIAGRA.
REVATIO vs VIAGRA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
REVATIO (sildenafil) is a phosphodiesterase type 5 (PDE5) inhibitor. By inhibiting PDE5, it increases cyclic guanosine monophosphate (cGMP) levels in pulmonary vascular smooth muscle, leading to vasodilation and reduced pulmonary vascular resistance.
Sildenafil inhibits phosphodiesterase type 5 (PDE5), increasing cGMP levels in corpus cavernosum, leading to smooth muscle relaxation and blood flow into the penis.
20 mg orally three times daily, administered 4-6 hours apart.
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
Terminal elimination half-life ~4 hours (range 3-5 hours) in steady state; similar in pulmonary arterial hypertension patients.
Terminal elimination half-life approximately 4 hours (range 3–5 hours). No significant accumulation with recommended dosing.
Primarily hepatic metabolism (CYP3A4) to N-desmethyl sildenafil (active). Renal excretion accounts for ~80% as metabolites; ~13% fecal.
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
PDE5 Inhibitor
PDE5 Inhibitor