Cetirizine vs Trimethoprim

## Cetirizine vs Trimethoprim: Overview

This comparison examines the pharmacological differences between **Cetirizine** and **Trimethoprim**.

## Mechanism of Action

**Cetirizine**: Second-generation H1 antihistamine.

**Trimethoprim**: Dihydrofolate reductase inhibitor (bacterial selective).

## Pharmacokinetics

**Half-life**: Cetirizine — 6.5-10 hours; Trimethoprim — 8-10 hours.

## Chemical Properties

**Molecular Formula**: Cetirizine — C21H25ClN2O3; Trimethoprim — C14H18N4O3.

**Molecular Weight**: Cetirizine — 388.8900 g/mol; Trimethoprim — 290.3180 g/mol.

**Type**: Cetirizine — Small molecule; Trimethoprim — Small molecule.