Chronic daily headache (CDH) is a common problem, affecting approximately 3 to 4% of the population. CDH poses a significant therapeutic challenge to both physician and patient.
For those with moderate or severe CDH, preventive medications are often utilized in an effort to limit analgesics and decrease headache frequency and/or severity. The primary first-line preventives include antidepressants (primarily selective serotonin reuptake inhibitors and tricyclics) and anticonvulsants. Antidepressants have been an attractive choice in those with comorbid depression and anxiety. Tricyclic antidepressants have been known to have enhanced efficacy of SSRI’s, but are not as well tolerated. The anticonvulsants sodium valproate and topiramate have emerged as effective drugs for use in CDH.
In our current study, only 46% of the patients obtained significant long-term relief from a preventive medication. While there are a variety of preventive 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 find that efficacy is lacking. Among those who do benefit, side effects such as weight gain and fatigue may, over time, cause them to discontinue the medication. The patient may also experience a decline in efficacy over time. Most of the new breakthrough medications have been in the abortive category—particularly the triptans. Currently there is a lack of new or novel headache preventives.
Many medications have been utilized in an effort to decrease severity and/or frequency of CDH. Short-term (less than six month) studies often demonstrate success at preventing CDH. However, the long-term success of these medications for CDH has not been demonstrated. In fact, while antidepressants and anticonvulsants demonstrated reasonable long-term efficiency, the majority of patients do not obtain adequate long-term relief from CDH preventive medications.
There is a lack of agreement between the results of short-term studies and those which we observed anecdotally regarding long-term success of daily preventive medications. We need longer-term studies, at least nine to twelve months in length, in order to adequately evaluate the daily preventives. In addition, we need a new approach to more effective daily preventive medications for chronic daily headache.