Diphenhydramine vs Gefitinib

## Diphenhydramine vs Gefitinib: Overview

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

## Mechanism of Action

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

**Gefitinib**: Selective reversible inhibitor of EGFR tyrosine kinase.

## Pharmacokinetics

**Half-life**: Diphenhydramine — 2-8 hours; Gefitinib — 48 hours.

## Chemical Properties

**Molecular Formula**: Diphenhydramine — C17H21NO; Gefitinib — C22H24ClFN4O3.

**Molecular Weight**: Diphenhydramine — 255.3550 g/mol; Gefitinib — 446.9000 g/mol.

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