Allopurinol vs Sildenafil

## Allopurinol vs Sildenafil: Overview

This comparison examines the pharmacological differences between **Allopurinol** and **Sildenafil**.

## Mechanism of Action

**Allopurinol**: Xanthine oxidase inhibitor reducing uric acid production.

**Sildenafil**: Selective PDE5 inhibitor increasing cGMP.

## Pharmacokinetics

**Half-life**: Allopurinol — 1-2 hours; Sildenafil — 4 hours.

## Chemical Properties

**Molecular Formula**: Allopurinol — C5H4N4O; Sildenafil — C22H30N6O4S.

**Molecular Weight**: Allopurinol — 136.1120 g/mol; Sildenafil — 474.5800 g/mol.

**Type**: Allopurinol — Small molecule; Sildenafil — Small molecule.