| Preventive Headache Measures at a Quick Glance by Val South, RN, World Headache Alliance, Oakville, Ontario, Canada Many people are able to treat their migraine successfully by first eliminating the controllable triggers; improving their physical, mental and emotional health; and treating the symptoms of any remaining attacks with non-drug strategies. Many rely on the occasional use of pain relievers or migraine-specific medications for attacks in progress. For others, migraine is more of a challenge to control. Those who experience three or more migraines per month, or who experience varities of migraine with dramatic symptoms, such as basilar migraine, may wish to consider preventive therapy with medications. Known medically as "prophylactic therapy," this is a regimen where specific types of medications are taken every day (whether there is a headache present or not) to right the biochemical imbalance that underpins migraine. The intended result is to decrease the frequency, intensity, or duration of migraine attacks. Preventive medications are not pain relievers. Preventive medications are often taken in small doses, and their potential to cause side effects may be less troublesome than the overuse of painkilling or symptomatic medications. Preventives take time to begin working. Therapy is usually continued for four to twelve months without interruption, then is tapered down or stopped for a period of evaluation. In many cases, the benefits received while taking the medication will continue for a time after the use of the drug is stopped. The migraine itself may enter a period of less activity or near-remission, or the break may be a residual effect of the medication. Some people find that, after a time, their body gets used to the preventive medication they are on, and the drug stops working. In this case, it is best to speak to the doctor about stopping the drug for a while and perhaps switching to another. Most people then find that, after a period, they can retry the original medication and it will begin to work again. Despite the proven effectiveness of preventive therapy for many, only about 6 percent of migraine sufferers were found in a 1990 survey to be taking daily preventive medicine. Some experts cite as an explanation the general lack of knowledge regarding the use of these medications in migraine; others believe some people may be reluctant to take medication daily even though it can substantially reduce the total consumption of pain relievers or other symptomatic medicines. Other factors may include side effects and cost; also, with the availability of the triptans, some people may have less need for preventive drugs. Beta-adrenergic Blockers Most prophylactic medications were originally developed to treat other disorders, and were discovered, through serendipity, also to be helpful in migraine. This is true of betablockers. These medications, which were developed to treat high blood pressure, were found to help reduce the number of migraines experienced by patients who also suffered from migraines. No one really knows how beta blockers work in migraine, but they have been shown to be helpful time and time again in clinical trials. They are the oldest and most widely used migraine preventive today. Common beta blockers used for the preventive treatment of migraine include propranolol; the oldest, nadolol, sometimes is favored because of the lower incidence of certain side effects; timolol maleate; atenolol; and metoprolol. A recent European study indicates that adding therapeutic riboflavin to beta-blocker therapy may increase the effectiveness of the treatment. Beta blockers may be a good choice for migraine prevention if high blood pressure also exists, since one drug can treat both conditions. They should not be used by people who suffer from asthma, diabetes, or certain heart problems. When it is time to stop taking beta blockers, use must be decreased gradually to prevent problems such as heart palpitations, high blood pressure, and a worsening of headaches. Potential side effects of beta blockers include a slower heartbeat, stomach upset, sleep disturbances, or a reduction or loss of libido (sex drive). They should be used only with caution in people with depression, and it should be noted that beta blockers can limit athletic performance. Calcium-channel blockers Like beta blockers, most calcium-channel blockers (except for flunarizine) were originally developed to treat certain heart problems. They too were coincidentally found to reduce the number of migraines experienced by some. Calcium-channel blockers are believed to work by stabilizing blood vessels through preventing them from either constricting (narrowing) or dilating (widening). The calcium-channel blocker verapamil is commonly used for the prevention of cluster headache. They do not cause a depletion of calcium in the body and will not cause osteoporosis. Migraine is not caused by an excess of calcium, and sufferers need not limit their calcium intake to avoid migraine or supplement their calcium intake while taking a calcium-channel blocker. Calcium-channel blockers take longer to begin to work, and may take up to two months to reach their peak effect. They too carry potential side effects and contraindications. Constipation is one of the most frequently reported side effects of verapamil. They are not suitable for people with certain types of heart disease. Commonly used calcium-channel blockers include verapamil and diltiazem. A special form of calcium-channel blocker was developed for use specifically with migraine. Flunarizine was designed to act only on the blood vessels of the head, and it does not have the heart effects that the regular calcium-channel blockers do. However, it should not be used by people with a history of depression. Like its calcium-channel blocking relatives, it can also cause weight gain and drowiness, among other side effects. It is available in Canada, but not in the U.S. Non-steroidal Anti-inflammatories (NSAIDs) Examples of these medicines include ibuprofen, naproxen, and naproxen sodium. NSAIDs need to be considered for their ability to act as preventive medications – especially when taken around the time of the menstrual period during the headache-prone days. It is very important to embark on this daily use of NSAIDs only under a doctor’s supervision, as taking NSAIDs excessively – even behind-the-counter ones such as ibuprofen – can lead to stomach irritation. Antidepressants Another class of prophylactic migraine medications has caused many misunderstandings between doctors and their patients. Antidepressants (used to treat depression0 are often used for migraine prevention. They are often prescribed for migraine at smaller doses than would be used to treat depression. Antipressants are helpful to some people with migraine as their chemical action helps to correct the chemical imbalances behind the migraine disorder. They also have pain-relieving properities, and are used for general pain relief in a variety of painful disorders. Misunderstanding will arise, however, if the patient does not understand why an antidepressant is being used for the treatment of pain. Uninformed migraine patients often think that the doctor secretly believes them to be depressed and doesn’t really understand migraine. Although depression can certainly accompany migraine, and has been shown to be more prevalent in migraine sufferers (migraine is also more prevalent in people with depression), most often the antidepressant is not being used to treat depression when prescribed for migraine prevention. Tricyclic antidepressants (sometimes referred to as tricyclic analgesics) commonly used for the treatment of migraine are amitriptyline, nortriptyline, and doxepin. Tricyclic antidepressants are contraindicated for use by people with some types of glaucoma, epilepsy, or heart-rhythm disturbances, or by men with enlargement of the prostate. Dryness of the mouth is a common side effect. The potential ability of tricyclic antidepressants to cause sedation is less of a problem if the medication is taken at bedtime or slightly earlier in the evening. The newer class of antidepressants known as SSRIs (selective serotonin reuptake inhibitors) is sometimes used for migraine prevention – especially if a mood disorder exists. Examples of SSRIs include fluoxetine, fluvoxamine, citalopram, paroxetine, and sertraline. They are considered to be less effective than the tricycles. Headache can occur as a side effect to SSRIs but it often goes away over time. Further studies of other drugs originally used for the treatment of psychiatric disorders, such as the MAO (monomine oxidase, an enzyme) inhibitor phenezine sulfate, are needed to tell us if they have any value in the treatment of migraine. MAOs are rarely used for migraine. (Interestingly, people who take MAO inhibitors must stick to a diet low in tyramine to avoid a serious drug reaction. Since migraine sufferers also benefit from a diet low in tyramine – a vasoactive substance believed to trigger migraine and present in foods such as aged cheese, red wine, pickled herring, etc. – many believe that the benefits of MAO inhibitor therapy in migraine stem from the diet, not the drug.) MAO inhibitors should not be taken in combination with SSRIs, cold medicines, some pain relievers, or certain other medications used to treat migraine. Check carefully with the doctor or pharmacist. Taking Your Preventive Medicines It is considered useful to continue taking preventive medications when the frequency of attacks experienced is reduced by half. Since breakthorough attacks are likely to occur, sufferers on a prophylactic regime should speak to their doctor about how to manage any remaining attacks. It is always important to report any side effects directly to the doctor, and an effort should be made not to miss doses of the prophylactic medication. The medication should be taken at the same time each day, whenever possible. Consult your pharmacist about possible drug interactions. Preventive medications must be taken every day whether there is a headache present or not. They will not be helpful if taken only when an attack strikes. Stay in touch with the doctor so that necessary adjustments may be made to the ongoing treatment, and never share medications with friends or family members. |
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