Authors suggest headache is a side effect of interferon

Authors of an open study conclude that headache may be a side effect of interferon treatment in MS patients.The authors say that, on the basis of their results, aggravation of pre-existing primary headaches or the occurrence of de novo headaches with clinical characteristics of migraine or tension-type headaches should be considered as side effects of interferon treatment for MS. However, they acknowledge that their results, based on a small, retrospective data set, need to be confirmed by results from a randomised, controlled study.The authors studied 150 consecutive MS patients treated at their clinic over an 8-month period with interferons or other immunotherapies for MS for at least three months. A total of 109 patients were treated with interferon β (IFN) and 41 patients were treated with another immunotherapy (14 with glatiramer acetate and 27 with azathioprine). All patients underwent a semi-structured questionnaire that collected information on lifetime headache occurrence, onset of headache, frequency of attacks, and a range of headache characteristics. The lifetime prevalence of headache was 72% in the IFN-treated patients and 54% in patients treated with other agents (P = 0.03). Pre-existing headaches (i.e. before immunomodulatory therapy for MS) were reported in 38% of IFN-treated patients and in 54% of patients treated with other therapies. The authors report, "De novo headaches occurred only in IFN-treated patients. Among the 79 patients treated with IFNs who reported headaches, 48% started to suffer headache after the onset of treatment. As no patient receiving azathioprine or glatiramer acetate showed either a relevant change in pre-existing headache or a de novo headache after therapy, the differences between the two treatment groups were highly significant (P The authors conclude, "These results show that headache should be considered among the side-effects of interferon in MS patients."Reference...