Diphenhydramine vs Ondansetron

## Diphenhydramine vs Ondansetron: Overview

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

## Mechanism of Action

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

**Ondansetron**: Selective 5-HT3 receptor antagonist.

## Pharmacokinetics

**Half-life**: Diphenhydramine — 2-8 hours; Ondansetron — 3-5 hours.

## Chemical Properties

**Molecular Formula**: Diphenhydramine — C17H21NO; Ondansetron — C18H19N3O.

**Molecular Weight**: Diphenhydramine — 255.3550 g/mol; Ondansetron — 293.3660 g/mol.

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