Is Medication Overuse Headache Overdiagnosed and Treated Appropriately?
by Lauren Doyle Strauss, DO
Patients suffering from headaches are often advised about a type of secondary headache called medication overuse headache or MOH. MOH was previously referred to as “rebound headaches” because of the rebounding headaches that would occur between regular doses of medications or “drug-induced headaches” because it was exacerbated from a medication. Medications that are prescribed or bought over the counter and used more frequently than thought to be safe can have risks associated with them (nausea, gastritis, effects on organ systems, etc.). However, MOH characterizes an additional theorized effect that persistent abortive headache medication can cause worsening in the frequency or severity of pre-existing headaches. The diagnosis of MOH is defined in the International Classification of Headache Disorders (ICHD) as headaches occurring >15 days/mo in a patient with a pre-existing headache disorder (migraine, tension-type headache, etc.) who has regularly exceeded specific thresholds of symptomatic medication use.
There has been consensus in the medical community about the importance of educating treating clinicians and patients to prevent this worsening by limiting use of abortive medications. Certainly not every medication is the same when it comes to the short-term and long-term effects on the brain, propensity to alleviate or worsen headaches, or the potential for side effects in overuse leading to a challenging situation to study the entity of MOH and how to treat it.
Dr. Ann Scher of the Uniformed Services University and Drs. Paul Rizzoli and Elizabeth Loder of the Graham Headache Center in Boston published recently in the August issue of Neurology “Medication overuse headache: An entrenched idea in need of scrutiny” looking at these concerns. According to the authors’ review of existing evidence, there does not appear to be a strong basis to substantiate the causal claims about the relationship between medication use and frequent headache.
Much of the preceding evidence is based on observational studies, and this study design by its nature can be affected or confounded by the natural association that a patient may need/take more medications because of worsening headaches. Other studies have tried to look at whether the treatment recommendation of withdrawing an overused medication leads to headache improvement, however, these studies have not had control patients for comparison and often have high dropout rates.
The authors raise the question of the strength of the research evidence that led to the consensus regarding treatment in these scenarios and also the potential resulting harm to the patient from undertreating pain trying to avoid or treat MOH.
There is a planned pragmatic trial called MOTS (Medication Overuse Treatment Strategy) lead by Dr. Todd Schwedt of the Mayo Clinic made possible by funding from the Patient-Centered Outcomes Research Institute (PCORI) that will try to further clarify treatment recommendations in MOH. The study will look at chronic migraine patients who are overusing abortive medications and will compare two treatment pathways in addition to placing on migraine prophylaxis: 1) discontinuation of abortive medication overuse and 2) no recommendation on limiting abortive medications. Further information on this trial can be found on clinicaltrials.gov website (NCT02764320).