Take, for example, the treatment of migraine. Any sufferer will tell you just how debilitating a condition it is. Drugs designed to treat it have their problems. Sumatriptan (marketed as Imigran) has been linked to heart problems, and even the newer triptans, such as Relpax, haven’t eradicated the concerns about triggering serious complications.

So if the existing drugs are found wanting, what about drugs to stop the condition before it starts? The heart drug lisinopril (marketed in the UK as Zestril) has helped some migraine sufferers, and so researchers in Norway decided to try out an angiotensin II receptor blocker, candesartan, as a prophylactic treatment on 60 migraine sufferers.

Half were given the drug for 12 weeks, and half had a placebo. The researchers found that the drug reduced, but couldn’t eliminate, the number of migraine days, and some in the drug group reported dizziness and fatigue.

But if the drug is used as a prophylactic, it will presumably need to be taken all the time, and the researchers were testing for just 12 weeks. The side-effects that come with Zestril, for example, suggest it’s a therapy that shouldn’t be taken lightly. Common reactions include hypotension, or low blood pressure, dizziness and, believe it or not, headache. Another reaction can be heart attack.

Now, we don’t want to belittle the suffering endured by migraine victims, but it does bring us back to our opening remark. Yes, attacks of migraine may be reduced, but rates of heart attack, and so possibly death, may have gone up as a consequence. Such can be the problems of seeing things in isolation.

(Source: Journal of the American Medical Association, 2003; 289: 65-9).