How to choose a preventive therapy?
Although choosing an effective medication often leads to a trial and error approach, there are some basic guidelines that are important to follow. It is necessary to consider the patient's other co-morbidities for 2 main reasons.25 The first reason is that a single medication can be used to treat more than 1 condition, for example, a patient with hypertension can be started on verapamil to treat both headaches and blood pressure. The other reason is to make sure that a medication is not contraindicated. For example, beta-blockers should be avoided in patients with a history of heart block. It is also important to keep in mind that the possible side effects of a preventive which may dissuade its use. For example, topiramate should be used with extreme caution in patients who have a history of kidney stones, as topiramate can increase the likelihood of additional stone formation.3 Choosing a preventative medication in a young woman who is pregnant or of child bearing age can be a challenge. Most medications are either absolutely or relatively contraindicated in pregnancy. Fortunately, most women experience an improvement or even a remission of their migraines during pregnancy. If needed, it is important to choose a medication with lowest risk of teratogenic effects.13