Allopurinol vs Diphenhydramine

## Allopurinol vs Diphenhydramine: Overview

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

## Mechanism of Action

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

**Diphenhydramine**: First-generation H1 antihistamine with anticholinergic properties.

## Pharmacokinetics

**Half-life**: Allopurinol — 1-2 hours; Diphenhydramine — 2-8 hours.

## Chemical Properties

**Molecular Formula**: Allopurinol — C5H4N4O; Diphenhydramine — C17H21NO.

**Molecular Weight**: Allopurinol — 136.1120 g/mol; Diphenhydramine — 255.3550 g/mol.

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