Overuse of acute medications. The criteria (see above) allow for combining days of acute medication use. For example, if a patient takes a combination analgesic on 5 days and a triptan on 5 different days, that would still be enough days of acute treatment to trigger medication overuse headache.
Variable pain location is a particular characteristic of medication overuse headache. Although the location may differ from day to day (front or back, rostral or caudal, unilateral or bilateral), it is the quantity not the quality or location of the headaches that suggests the diagnosis.
A drug-dependent rhythm. Predictably, the headaches come on in the early morning or awaken the patient from sleep. This may be due to variable drug withdrawal.
Neck pain. Medication overuse headache frequently involves the neck, and patients often seek and receive treatments such as muscle relaxants or injections to the neck. When patients are weaned from their acute migraine medications, neck pain generally dissipates. The neck pain, however, can recur episodically with their remaining, now-episodic acute migraines. Neck pain associated with medication overuse headache is not usually a sign of a primary neck disorder; rather, it is a symptom of medication overuse headache itself.
Concomitant depression and anxiety are comorbid with episodic migraine, but appear to be more common with medication overuse headache. Treating the depression or anxiety does not restore an episodic pattern of migraine; weaning from the overused medications remains the most important intervention. A frequent clinical error is to diagnose and treat the psychiatric issues without recognizing medication overuse as the primary problem.
Nonrestorative sleep is almost always reported by patients with medication overuse headache. This is often due to the caffeine contained in combination analgesics or to excessive dietary caffeine intake, but it may also be part of the daily acute drug withdrawal syndrome. The sleep problems are also associated with the concomitant depression. Sleep often improves after weaning from the offending substance or substances. As with neck pain, patients do not have a primary sleep disorder—the sleep disturbance is a symptom of medication overuse headache.
Vasomotor instability. Autonomic features are commonly associated with medication overuse headache. Rhinorrhea, nasal stuffiness, and lacrimation are features of medication withdrawal, especially from opioids, and are frequently attributed to sinus disease or “sinus headaches.” Many patients undergo unnecessary sinus procedures or are given antibiotics, decongestants, and other wrong medications for incorrect diagnoses. Decongestants can cause and exacerbate medication overuse headache, so they need to be withdrawn. The sinus features generally remit when the overused migraine medications are eliminated.
Preventive medications are less effective or ineffective until the acute medications are withdrawn. Thus, prescribing prevention without weaning is usually futile, and the patients are often dismissed as having a refractory problem. At the same time, migraine-specific acute treatments, ie, triptans and ergots, are usually also less effective. When patients complain that “nothing works,” either preventively or acutely, medication overuse headache should spring to mind.
Weaning from overused medications can restore the efficacy of previously ineffective treatments at the same time that a patient is restored to an episodic headache pattern. Thus, complete weaning is the pivotal clinical intervention. Clinically, there is no spontaneous remission from rebound without absolute detoxification, maintained for months. 9,19–22