This document provides information on 5 medications - irbesartan, prednisone, zolpidem, sildenafil, and methotrexate. For each medication, it lists the primary diagnosis or use, generic and brand names, classification, mechanism of action, side effects, indications, and contraindications. The medications cover a range of therapeutic areas including hypertension, inflammation, insomnia, erectile dysfunction, and cancer. Sources of the information are also provided.