Chronic migraine: medication overuse headache.

The diagnosis of chronic migraine implies that a patient has a history of migraine headaches and that he/she now is experiencing headache at least 15 days out of the month. Chronic migraine is common, afflicting about 1 in 50 citizens. Effective management of chronic migraine involves prescription of a daily preventive medicine intended to decrease headache frequency; aggressive acute treatment of such headaches that occur despite the preventative medication and, last but not least, identification and treatment of any conditions that may be contributing to the chronic headaches. The conditions that most commonly aggravate chronic migraine are impaired sleep, a disorder of mood (typically depression, anxiety, or both), hormonal influences (pregnancy, recent childbirth, oral contraceptive use), and analgesic overuse. An analgesic is any medication intended for the relief of pain, whether it be humble acetaminophen (Tylenol) or a potent opioid (“narcotic”). Patients with chronic headache understandably tend to take analgesics frequently in an effort to reduce their pain and so enable themselves to carry out their routine activities. Unfortunately, virtually all of the medications—prescription or over-the-counter (OTC)—widely taken by migraineurs for the treatment of acute headache can promote headache when used too often over a period of weeks to months; some of the most common culprits are acetaminophen (eg, Tylenol), compounds containing acetaminophen plus caffeine (eg, Excedrin, Goodys, BC powders), butalbital-containing compounds (eg, Esgic, Fioricet, Fiorinal), and hydrocodone (eg, Lorcet, Lortab, Vicodin). Even the triptans (eg, sumatriptan: Imitrex) may cause medication overuse headache (MOH). In seeking to avoid MOH, how much is too much? In other words, how long can one take a given analgesic at a given frequency and in a given dose before MOH becomes a real possibility? Put yet another way, how does the patient with chronic migraine know whether the analgesic he/she frequently takes is helping or contributing to the very problem (headache) that provoked its use in the first place? The most realistic answer is: it depends. The potential for developing MOH is likely a function of the individual patient’s unique biology and, perhaps even more important, the particular drug in question. Some investigators have reported that of all the drugs commonly used for acute migraine treatment, it is the triptans that have the highest potential for producing MOH. At the other end of the spectrum, the nonsteroidal anti-inflammatory drugs (NSAIDs) are believed to have the lowest potential for producing this complication. The OTC agents are the “sneakiest” among this group. The fact that they are effective therapies when used appropriately and are so readily available and relatively cheap lures many migraineurs into steadily increasing their use of a given product, so becoming hopelessly stuck in the desolate swamp of MOH. How do you know if you may have a component of MOH? The following checklist may help.