RESUMO
BACKGROUND: Definitions of medication overuse headache have changed over time. OBJECTIVE: To evaluate the clinical characteristics of medication overuse headache patients admitted for inpatient withdrawal therapy over a period of 32 years. METHODS: We included all patients with medication overuse headache treated from 1 January 1984 to 31 December 2015. We obtained all data from the medical reports and defined three periods, P1 (1984-1993), P2 (1994-2003), and P3 (2004-2015). The p-value adjusted for multiple comparisons was set to 0.005. RESULTS: Within 32 years, a total of 787 patients accounted for 904 admissions for MOH. From P1 to P3, the proportion of patients with preexisting migraine increased from 44.3% to 53.3% (chi2 = 9.0, p = 0.01) and that with preexisting tension-type headache decreased from 47.9% to 34.6% (chi2 = 9.3, p < 0.01). The median time since onset of headache and medication overuse headache decreased from 20 to 15 years (p < 0.001) and from 3 to 2 years (p < 0.001). The median cumulative number of single doses decreased from 120 to 90 per month (p = 0.002). Overuse of triptans, non-opioid analgesics, and opioids increased, whereas overuse of ergotamines decreased over time (p < 0.001 for all tests). The use of prophylactic medication before admission increased from 8.3% to 29.9% (chi2 = 89.5, p < 0.001). CONCLUSION: This retrospective study in a large number of patients with medication overuse headache admitted for inpatient withdrawal therapy over a period of 32 years shows a trend towards changes in the preexisting headache type, a decrease in the time since onset of headache and medication overuse headache, a decrease in the number of drug doses used per month, changes in the type of drugs overused, and an increase in, but still low rate, of prophylactic medication prior to admission.
