Sildenafil

Category: pharmacological

Aliases: Viagra, Revatio

Pharmacological Mechanism

PDE5 inhibitor — raises cGMP in cavernosal smooth muscle → erectile vasodilation. CYP3A4 substrate (DDI with all azoles, ritonavir, grapefruit). Higher dose (Revatio) for pulmonary arterial hypertension.

Half-Life (t½)

PO: 4h

Dosing Guidelines

• PO: Typical 50mg (Range: 25 - 100 mg)

Target Organ Systems

• cardiovascular
• respiratory
• digestive
• reproductive