This document provides instructions for using a sumatriptan autoinjector pen to treat acute migraine headaches. It explains how to prepare the pen for injection, including removing the cap and ensuring the needle cover is inside. Step-by-step directions are given for injecting the medication, including pressing the pen against the skin, pressing the button to start injection, waiting 5 seconds before removing the pen, and disposing of it after single use. Important safety information is also provided about when not to use sumatriptan and potential side effects.