Definition
Medicines used to prevent or reduce the severity of migraine headaches are antimigraine drugs.
Purpose
Migraine headaches usually cause a throbbing pain on one side of the head. Nausea, vomiting, dizziness, increased sensitivity to light and sound, and other symptoms may accompany the pain. The attacks may last for several hours or for a day or more and may come as often as several times a week. Some people who get migraine headaches have warning signals before the headaches begin, such as restlessness, tingling in an arm or leg, or seeing patterns of flashing lights. This set of signals is called an aura. The antimigraine drugs discussed in this section are meant to be taken as soon as the pain begins, to relieve the pain and other symptoms. Other types of drugs, such as antiseizure medicines, antidepressants, calcium channel blockers and beta blockers, are sometimes prescribed to prevent attacks in people with very severe or frequent migraines.
Description
Migraine is thought to be caused by electrical and chemical imbalances in certain parts of the brain. These imbalances affect the blood vessels in the brain -- first tightening them up, then widening them. As the blood vessels widen, they stimulate the release of chemicals that increase sensitivity to pain and cause inflammation and swelling. Antimigraine drugs are believed to work by correcting the imbalances and by tightening the blood vessels.
Examples of drugs in this group are ergotamine (Cafergot), sumatriptan (Imitrex), rizatriptan (Maxalt) and zolmitriptan (Zomig). These medicines are available only with a physician's prescription and come in several forms. Ergotamine is available as tablets and rectal suppositories; sumatriptan as tablets, injections, and nasal spray; and zolmitriptan as tablets.
Recommended dosage
Recommended dosage depends on the type of drug. Typical recommended dosages for adults are given below for each type of drug.
Ergotamine
Take at the first sign of a migraine attack. Patients who get warning signals (aura) may take the drug as soon as they know a headache is coming.
Tablets
No more than 6 tablets for any single attack.
No more than 10 tablets per week.
Suppositories
No more than 2 suppositories for any single attack.
No more than 5 suppositories per week.
Sumatriptan
Take as soon as pain or other migraine symptoms begin. Also effective if taken any time during an attack. Do not take the drug until the pain actually starts as not all auras result in a migraine.
Tablets
Usual dose is one 25-mg tablet, taken with water or other liquid.
Doses should be spaced at least 2 hours apart.
Anyone with liver disease should consult with a physician for proper dosing.
Injections
No more than 6 mg per dose, injected under the skin.
No more than two 6-mg injections per day. These doses should be taken at least 1 hour apart.
Zolmitriptan
Take as soon as symptoms begin.
Tablets
Usual dose is 1-5 mg. Additional doses may be taken at 2-hour intervals.
No more than 10 mg per 24 hour period.
General dosage advice
Always take antimigraine drugs exactly as directed. Never take larger or more frequent doses, and do not take the drug for longer than directed.
If possible, lie down and relax in a dark, quiet room for a few hours after taking the medicine.
Precautions
These drugs should be used only to treat the type of headache for which they were prescribed. Patients should not use them for other headaches, such as those caused by stress or too much alcohol, unless directed to do so by a physician.
Anyone whose headache is unlike any previous headache should check with a physician before taking these drugs. If the headache is far worse than any other, emergency medical treatment should be sought immediately.
Taking too much of the antimigraine drug ergotamine (Cafergot), can lead to ergot poisoning. Symptoms include headache, muscle pain, numbness, coldness, and unusually pale fingers and toes. If not treated, the condition can lead to gangrene (tissue death).
Sumatriptan (Imitrex), rizatriptan (Maxalt) and zolmitriptan (Zomig) may interact with ergotamine. These drugs should not be taken within 24 hours of taking any drug containing ergotamine.
Some antimigraine drugs work by tightening blood vessels in the brain. Because these drugs also affect blood vessels in other parts of the body, people with coronary heart disease, circulatory problems, or high blood pressure should not take these medicines unless directed to do so by their physicians.
Special conditions
People with certain other medical conditions or who are taking certain other medicines can have problems if they take antimigraine drugs. Before taking these drugs, be sure to let the physician know about any of these conditions:
Allergies
Anyone who has had unusual reactions to ergotamine, caffeine, sumatriptan, zolmitriptan, or other antimigraine drugs in the past should let his or her physician know before taking the drugs again. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.
Pregnancy
Women who are pregnant should not take ergotamine (Cafergot). The effects of other antimigraine drugs during pregnancy have not been well studied. Any woman who is pregnant or plans to become pregnant should let her physician know before an antimigraine drug is prescribed.
Breastfeeding
Some antimigraine drugs can pass into breast milk and may cause serious problems in nursing babies. Women who are breastfeeding should check with their physicians about whether to stop breastfeeding while taking the medicine.
Other medical conditions
Before using antimigraine drugs, people with any of these medical problems should make sure their physicians know about their conditions:
- Coronary heart disease
- Angina (crushing chest pain)
- Circulatory problems or blood vessel disease
- High blood pressure
- Liver problems
- Kidney problems
- Any infection
- Eye problems.
Use of certain medicines
Taking antimigraine drugs certain other drugs may affect the way the drugs work or may increase the chance of side effects.
Side effects
The most common side effects are fluid retention, flushing; high blood pressure; unusually fast or slow heart rate; numbness; tingling; itching; nausea; vomiting; weakness; neck or jaw pain and stiffness; feelings of tightness, heaviness, warmth, or coldness; sore throat; and discomfort of the mouth and tongue.
More serious side effects are not common, but they may occur. If any of the following side effects occur, call a physician immediately:
- Tightness in the chest
- Bluish tinge to the skin
- Cold arms and legs
- Signs of gangrene, such as coldness, dryness, and a shriveled or black appearance of a body part
- Dizziness
- Drowsiness
- Shortness of breath or wheezing
- Skin rash
- Swelling of the eyelids or face.
Other side effects may occur with any antimigraine drug. Anyone who has unusual symptoms after taking this medicine should get in touch with his or her physician.
Interactions
Antimigraine drugs may interact with other medicines. When this happens, the effects of one or both of the drugs may change, or the risk of side effects may be greater. Anyone who takes these drugs should let the physician know all other medicines he or she is taking. Among the drugs that may interact with antimigraine drugs are:
- Beta blockers such as atenolol (Tenormin) and propranolol (Inderal)
- Drugs that tighten blood vessels such as epinephrine (EpiPen) and pseudoephedrine (Sudafed)
- Nicotine such as cigarettes or Nicoderm, Habitrol, and other smoking-cessation drugs
- Certain antibiotics, such as erythromycin and clarithromycin (Biaxin)
- Monoamine oxidase inhibitors such as phenelzine (Nardil) and tranylcypromine (Parnate)
- Certain antidepressants, such as sertraline (Zoloft), fluoxetine (Prozac), and paroxetine (Paxil)
- Fluvoxamine (Luvox), prescribed for obsessive compulsive disorder or chronic pain.
Remember sumatriptan, rizatriptan and zolmitriptan may interact with ergotamine. These drugs should not be taken within 24 hours of taking any drug containing ergotamine.
Key Terms
- Aura
- A set of warning symptoms, such as seeing flashing lights, that some people have 10-30 minutes before a migraine attack.
- Inflammation
- Pain, redness, swelling, and heat that usually develop in response to injury or illness.
Further Reading
For Your Information
Books
- Duckro, Paul N., William D. Richardson, and Janet E. Marshall. Taking Control of Your Headaches: How to Get the Treatment You Need. New York, NY: The Guilford Press, 1995.
Organizations
- American Council for Headache Education (ACHE). 19 Mantua Road, Mt. Royal, NJ 08061. (800) 255-2243. http://www.achenet.org.
- National Headache Foundation. 428 W. St. James Place, Chicago, IL 60614. (800) 843-2256. http://www.headaches.org.
- National Institute of Neurological Disorders and Stroke. P.O. Box 5801, Bethesda, MD 20824. (800) 352-9424. http://www.ninds.nih.gov.
Gale Encyclopedia of Medicine. Gale Research, 1999.