§ Telehealth Basics
Sildenafil
A PDE5 inhibitor (Viagra) used for erectile dysfunction; the prototype of the class.
Fact-checked 12 May 2026Plain-English Reference
Sildenafil's 4-5 hour half-life makes it well suited for on-demand use. Generic sildenafil is widely available at low cost. It is contraindicated with nitrates and should be used cautiously with alpha-blockers.