Erlotinib vs Methotrexate

## Erlotinib vs Methotrexate: Overview

This comparison examines the pharmacological differences between **Erlotinib** and **Methotrexate**.

## Mechanism of Action

**Erlotinib**: Reversible inhibitor of EGFR (HER1) tyrosine kinase, blocking autophosphorylation.

**Methotrexate**: Dihydrofolate reductase inhibitor.

## Pharmacokinetics

**Half-life**: Erlotinib — 36 hours; Methotrexate — 3-10 hours.

## Chemical Properties

**Molecular Formula**: Erlotinib — C22H23N3O4; Methotrexate — C20H22N8O5.

**Molecular Weight**: Erlotinib — 393.4380 g/mol; Methotrexate — 454.4400 g/mol.

**Type**: Erlotinib — Small molecule; Methotrexate — Small molecule.