Diphenhydramine vs Phenytoin

## Diphenhydramine vs Phenytoin: Overview

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

## Mechanism of Action

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

**Phenytoin**: Sodium channel blocker stabilizing inactive state.

## Pharmacokinetics

**Half-life**: Diphenhydramine — 2-8 hours; Phenytoin — 22 hours.

## Chemical Properties

**Molecular Formula**: Diphenhydramine — C17H21NO; Phenytoin — C15H12N2O2.

**Molecular Weight**: Diphenhydramine — 255.3550 g/mol; Phenytoin — 252.2680 g/mol.

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