Objectives: To determine the percentages of patients who discontinued treatment with the multiple sclerosis medications intramuscular interferon beta-1a (IFN-beta-1a; Avonex-Biogen), interferon beta-1b (IFN-beta-1b; Betaseron-Berlex), and glatiramer acetate (Copaxone-Teva) and to determine the factors that led to discontinuation of the medications.
Design: Cross-sectional study.
Setting: University-based neurology clinic.
Patients: 108 patients with multiple sclerosis who were prescribed intramuscular interferon beta-1a, subcutaneous interferon beta-1b, or subcutaneous glatiramer acetate.
Intervention: Telephone survey.
Main outcome measures: Discontinuation percentages and the factors that contributed to discontinuation.
Results: There was no significant difference between the percentages of patients who discontinued and did not restart treatment with the products (interferon beta-1b, 41%; intramuscular interferon beta-1a, 34%; and glatiramer acetate, 28%). Four main reasons for medication discontinuation emerged: adverse effects (52%), physician-documented disease progression (40%), patient perception of drug ineffectiveness (20%), and cost (4%). No statistical differences were identified among the three agents for any of the reasons for discontinuation.
Conclusion: Patient education on adverse effects and realistic patient expectations may be potential areas of study to improve discontinuation percentages with these agents.