The findings suggests that existing migraine preventative medications are commonly prescribed in idiopathic intracranial hypertension, the most common of which were acetazolamide and topiramate.
Cross-sectional analyses from a population-based, retrospective cohort study showed that women with idiopathic intracranial hypertension (IIH) were more likely to be prescribed opiate and simple analgesics compared with migraine or population controls. All told, these data may point towards a refractory nature of IIH headache.1
The analysis included data on 3411 women with IIH, 13,966 women with migraine as controls, and 33,495 population controls from 1995 to 2019. Considered the largest national study of its kind, the findings showed that twice as many women with IIH were prescribed opiates compared with migraine controls and 3 times as many women with IIH were prescribed opiates compared with population controls. Similar odds were observed for prescribing preventive drugs in women with IIH relative to the other groups.
Senior investigator Alexandra J. Sinclair, PhD, MBChB, MRCP, University of Birmingham, and colleagues concluded that these findings are a “major concern,” adding that, "there are likely to be multiple contributing factors, including the major burden of headache these patients experience. However, the consequences of such dominant opiate use in IIH are likely to be extensive and contribute to the poor quality of life that has previously been noted."
All patients were followed-up from index date until the date of the earliest of the following end points: outcome, death, patient left the practice, practice ceased contributing to the database, or study end (September 2019). The mean age in prevalent and incident IHH and population controls was 34 years. Compared with both control groups, the proportion of participants with back pain, polycystic ovary syndrome, osteoarthritis, epilepsy, fibromyalgia, sleep apnea, and severe mental illness was higher in women with IIH.
Acetazolamide, a medication used to prevent and reduce the symptoms of altitude sickness, was the most common drug prescribed among women with IHH within their first year of diagnosis (58%), followed by topiramate (Topamax; Janssen; 20%). In total, 20% of women with IIH were prescribed opiates within the first year of their diagnosis, reduced to 17% after 6 years, compared with an increase from 8% to 11% of migraine controls.
From the point of diagnosis, the proportion of women with IHH prescribed analgesics remained relatively constant, with a slight decrease in simple analgesics over time. Although there were significantly larger proportions of women with IHH prescribed opiates, triptan use was most common in migraine controls. Between the 3 groups, a higher proportion of women with IIH were prescribed epilepsy class drugs, tricyclic antidepressants, and candesartan. By 3 years from the time of diagnosis, women with IIH were more likely to have tried 2, 3, or more than 3 preventatives than migraine controls. Those with IIH and migraine controls had similar use of beta-blockers, with a roughly 2- to 3-fold higher proportion prescribed than population controls.
In a subgroup analysis, the crude incidence of new onset headache was 71.6 and 23.9 per 1000 person-years in the IIH (n = 1455) and population control (n = 26,403) groups, respectively. Compared with controls, the adjusted hazard ratio (aHR) for new onset headache in women with IIH was 3.09 (95% CI, 2.78-3.43), which increased to 4.92 (95% CI, 4.21-5.74) in a sensitivity analysis restricted to only women with incident IIH and their corresponding controls.
A total of 2865 women with IIH and 33,495 population controls were included in the analysis with a diagnosis of new onset migraine. The crude incidence of migraine was 18.0 and 7.5 per 1000 person-years in the IIH and population control groups, respectively, resulting in an adjusted HR of 2.32 (95% CI, 2.01-2.67). Similarly, in a sensitivity analysis restricted to only women with incident IIH and their corresponding controls, the adjusted HR was 3.25 (95% CI, 2.69-3.91).
Sinclair et al concluded that, "Headache management in IIH remains an unmet clinical need, and development of targeted therapies may help reduce the multiple prescriptions of preventative migraine medications and curb the opiate prescribing trends."