Viagra

Viagra, with the active compound sildenafil citrate, is a selective phosphodiesterase type 5 (PDE5) inhibitor originally developed for cardiovascular applications before becoming the first FDA-approved oral therapy for erectile dysfunction. Its mechanism involves:

• Potentiation of nitric oxide (NO)-mediated vasodilation
• Inhibition of cGMP degradation in smooth muscle tissue
• Enhanced blood flow to genital vascular networks

Clinical pharmacology studies demonstrate:

• Onset of action within 30-60 minutes

• Duration of effect lasting approximately 4 hours

• Peak plasma concentrations at 30-120 minutes post-dose

Research continues to explore:

1. Vascular applications beyond erectile dysfunction

2. Potential pulmonary hypertension benefits

3. Effects on endothelial function

4. Gender-specific vascular responses

The compound requires sexual stimulation for therapeutic effect and is contraindicated with nitrate medications. Ongoing research investigates its pharmacokinetic profile and potential applications in vascular medicine.