Treatment
Before initiating therapy, it is important to determine the presence of MOH. MOH should be suspected in patients who use analgesics, triptans, opioids, or combination agents >10 days per month. The ICHD-II criteria for MOH require that the headache be chronic (present >45 d) over a 3-month period. The headache should worsen with medication use and improve within 2 months of medication withdrawal. The treatment of MOH can be difficult. In most cases a rapid withdrawal is required, accompanied by provision of acute symptomatic therapy no more than 2 days per week. The establishment of a prophylactic regimen should follow immediately. Patients requiring additional analgesia may be bridged with either naproxen or indomethacin, as these seem to be safe from an MOH point of view.
In addition, previous headache diagnoses must be considered and the presence of any comorbid depression or anxiety disorder. These latter disorders seem to occur with greater frequency in IIH patients despite control of the IIH, and they are known to make headache management more difficult.
Finally, the overall status of the patient's IIH must be considered. Recurrent IIH should be considered in those patients with marked worsening of headache, especially if accompanied by visual changes and pulse synchronous tinnitus.
Medical Therapy
Preventative. Preventative therapy is indicated in all patients with >=5 primary headaches per month. The aim of the preventative therapy is to reduce the headache frequency by at least 50%. The choice of agent should be guided by the headache phenotype, with tension-type headache and migraine without aura being the most common.
Topiramate was discussed previously but bears mentioning again, as this is one of the few agents that has level A evidence for the treatment of migraine. It also has the advantage of inducing significant anorexia, which can aid in weight loss in these patients.
The β-blockers also have level A evidence for the prevention of migraine. However, these drugs are known to cause exercise intolerance and may lead to depression. Therefore, they should be used more cautiously in this susceptible population.
Tricyclic antidepressants have level A evidence for the treatment of both migraine and tension-type headaches. As they are sleep inducing they can be useful in patients with insomnia if taken at bedtime. However, weight gain is a frequent side effect and limits their use in IIH patients. Sodium valproate, although also effective, should be avoided as it frequently causes rapid weight gain.
Symptomatic. Symptomatic therapy is often necessary even in the setting of preventative medication use in order to treat acute "break-through" headaches. The use of acute symptomatic therapy should be limited to no more than 2 days per week, as more frequent use raises the risk of MOH. Standard acute therapies can be used in conjunction with preventative therapy. Triptans are prescribed most commonly for migraine, and nonsteroidal anti-inflammatory drugs such as naproxen and indomethacin can be used for both migraine and tension-type headache. There is some evidence that indomethacin also helps to lower ICP, making it a good choice in this population.Table 2 summarizes the most frequently used preventative and symptomatic agents.