[Profile of efficacy and safety in the treatment of remittent-recurrent multiple sclerosis with interferon beta-1b].

BACKGROUND: Interferon beta 1b (IFN beta-1b) has showed a reduction of exacerbation rate and a decrease in multiple sclerosis activity as evidenced by MRI. After the approval of IFN beta-1b in our country more than 1,000 patients are under treatment, however the experience is limited. The purpose of this study is to describe the clinical results and the tolerance of IFN beta-1b during the postmarketing period in our country. MATERIAL AND METHODS: We studied 95 patients treated with IFN beta-1b. An exhaustive follow-up has been performed in order to assess the tolerance and the efficacy of the drug. We registered the haematological and biochemical abnormalities, secondary effects, relapses, clinical evolution and drop-outs. RESULTS: Mean age was 32.5 +/- 9 years, and the mean follow-up was 13.2 months. Seventy patients (74%) have been followed for more than one year. Haematological abnormalities are frequent, lymphopenia being the most common finding (37%). Flulike symptoms appear in 90% of the patients and skin reaction in the 70%. We have observed a drop-out rate of 7%. One patient developed depressive symptoms and the treatment was temporally discontinued. We have observed a significant decrease in relapses of the disease, however disability has not changed in the first year after treatment. CONCLUSIONS: IFN beta-1b has been well tolerated in the postmarketing period. The profile of secondary effects is similar, although not identical to that reported. The patient awareness of secondary effects and the realistic expectations of the drug are important in order to decrease the drop-out rate.