Frequency and severity of headache is worsened by Interferon-β therapy in patients with multiple sclerosis

Background - The relationship between multiple sclerosis (MS) and headache (HA) is not well known. It was reported that interferon-beta (IFN beta) could induce or worsen HA. Objective - To evaluate the impact of IFN beta treatment on HA and the relationship between HA and the various commercial preparations of IFN beta in mildly disabled patients with MS. Methods - A specific questionnaire was administered to 357 relapsing-remitting MS patients. Characteristics of HAs were considered, including the temporal relationships with IFN beta administration. Results - One hundred and seventeen patients were treated with weekly intramuscular injections of interferon IFN beta-1 alpha (Avonex(R)), 84 with subcutaneous injections of IFN beta-1b (Betaferon(R)) every other day, 48 and 108 with three times weekly subcutaneous injections of IFN beta-1 alpha (Rebif(R)) 22 mcg or IFN beta-1 alpha (Rebif(R)) 44 mcg, respectively. Three hundred and fourteen patients were affected by HA, and among them, 219 patients suffered of pre-existing HA. In this latter group, 121 subjects (55%) noted a worsening of their HA after starting IFN beta therapy; this was more frequently reported by patients treated with Avonex(R) and Rebif(R) 44. Ninety-five patients experienced new HA. Conclusion - IFN beta treatment could worsen HA in patients with pre-existing HA or cause the appearance of new HA. Among different IFN beta preparations, Rebif(R) 44 and Avonex(R) seemed to be more cephalalgic than the other drugs