Patient Information Regarding Subcutaneous Self-Administration of Sumatriptan (Imitrex)
Written instructions and accompanying photographs dealing with self-administration of sumatriptan are available at most pharmacies and are enclosed in the self-dosing kit you will receive with your initial prescription. While preparation of the auto-injector is not particularly difficult, it is a good idea to familiarize yourself with its use during a quiet time when you are free of headache or other distractions. You may load the auto-injector at your leisure and thus have the auto-injector ready to use when you need it for severe headache.
You should not take sumatriptan if you have a history of heart disease, poorly controlled high blood pressure, or severe blood vessel spasm of any type. You should not use sumatriptan if you are experiencing chest pain along with an acute headache. If you are uncertain as to whether it is safe for you to use sumatriptan, consult your doctor.
Sumatriptan should not be administered within 24 hours of your taking an ergotamine preparation (examples include Cafergot, Ergocaff PB, dihydroergotamine/DHE), and you must wait at least 6 hours after administering sumatriptan before taking any ergotamine preparation. Taking sumatriptan and an ergotamine simultaneously or too close together may result in blood vessel spasm and, potentially, angina, heart attack, or stroke. Sumatriptan should be used cautiously in individuals also taking an MAO inhibitor (eg, Nardil).
Common side effects of sumatriptan include nausea, temporary increase in headache, facial flushing or tingling, short-lived pain at the injection site, and a temporary sensation of muscle “tightening,” which most often involves the neck or chest. Less common potential side effects include a “burning” or “scalding” sensation involving the skin, and allergic reactions (extending from rash to anaphylactic “shock”). There are reports, albeit very rare, of true angina, heart attack, heart arrhythmia, or stroke as possible complications of sumatriptan use. Used as indicated, however, all data indicate that injectable sumatriptan is exceedingly safe.
Administering a second injection of sumatriptan following initial injection is unlikely to help your headache if the initial injection was ineffective. On the other hand, many patients experience recurrent headache within 24 hours following successful treatment of their headaches with the initial sumatriptan injection, and, if such is your experience, you may give yourself a second injection to treat this recurrent headache. The recommended maximum total number of injections per 24-hour period is 2.
To maximize your therapeutic response to injectable sumatriptan and minimize side effects, administer the medication as soon as your headache reaches the level of moderate or severe intensity.
John F. Rothrock, MD