In the study conducted by Dr. Robbins and Joseph Maides, Jr., DO, only 46% of tested patients obtained significant long-term relief from a preventative medication. Lack of efficacy was cited as the primary reason for medication discontinuation.
Chronic daily headache poses a significant problem, with 3 to 4% of the population suffering from this condition. There are a variety of preventative medications available, including (but not limited to): sodium valproate, antidepressants, beta blockers, muscle relaxants, NSAIDS, gabapentin and topiramate. Many patients cannot tolerate these medications, or efficacy is lacking. Among those who do benefit, over time the side effects (such as weight gain or fatigue) may cause discontinuation of the medication. Alternatively, the patient may experience declining efficacy. Most of the new breakthrough medications have been in the abortive category (particularly the triptans). There has been a lack of new, novel headache preventatives.
Overuse of analgesics, on a chronic basis, may cause or exacerbate daily headaches. For these patients, withdrawal of the analgesics often will lead to an improvement in the headache. The usual preventative medications may be ineffective for those who are overusing analgesics.
There is no doubt that chronic daily headache sufferers are difficult to successfully treat, and medication overuse is a major factor. Initially, studies indicate a widely varying success rate for the treatment of chronic daily headache, between 47 and 97%. However, after four years, many of the patients who were able to discontinue their analgesics relapsed into medication abuse (44% in one study, 60% in another study). Even after one year, 30 to 35% of patients relapsed into overuse of the analgesics. These patients usually have a poor quality of life. One major contributing factor to the medication overuse is the failure of the preventattive medications to adequately decrease the chronic daily headache.
There is a disconnect between the results of company-sponsored short-term studies and what we observe, albeit anecdotally, regarding long-term success of dailly preventatives. We need long-term studies, at least six to nine months, in order to adeequately evaluate daily preventatives. In addition, we need novel, more effective daily preventatives for chronic daily headache.