title: The prevalence of injection-site reactions with disease-modifying therapies and their effect on adherence in patients with multiple sclerosis: an observational study.
abstract: BACKGROUND
  Interferon beta (IFNβ) and glatiramer acetate (GA) are administered by subcutaneous (SC) or intramuscular (IM) injection. Patients with multiple sclerosis (MS) often report injection-site reactions (ISRs) as a reason for noncompliance or switching therapies. The aim of this study was to compare the proportion of patients on different formulations of IFNβ or GA who experienced ISRs and who switched or discontinued therapy because of ISRs.
  
  
  METHODS
  The Swiss MS Skin Project was an observational multicenter study. Patients with MS or clinically isolated syndrome who were on the same therapy for at least 2 years were enrolled. A skin examination was conducted at the first study visit and 1 year later.
  
  
  RESULTS
  The 412 patients enrolled were on 1 of 4 disease-modifying therapies for at least 2 years: IM IFNβ-1a (n = 82), SC IFNβ-1b (n = 123), SC IFNβ-1a (n = 184), or SC GA (n = 23). At first evaluation, ISRs were reported by fewer patients on IM IFNβ-1a (13.4%) than on SC IFNβ-1b (57.7%; P < 0.0001), SC IFNβ-1a (67.9%; P < 0.0001), or SC GA (30.4%; P = not significant [NS]). No patient on IM IFNβ-1a missed a dose in the previous 4 weeks because of ISRs, compared with 5.7% of patients on SC IFNβ-1b (P = 0.044), 7.1% of patients on SC IFNβ-1a (P = 0.011), and 4.3% of patients on SC GA (P = NS). Primary reasons for discontinuing or switching therapy were ISRs or lack of efficacy. Similar patterns were observed at 1 year.
  
  
  CONCLUSIONS
  Patients on IM IFNβ-1a had fewer ISRs and were less likely to switch therapies than patients on other therapies. This study may have implications in selecting initial therapy or, for patients considering switching or discontinuing therapy because of ISRs, selecting an alternative option.
authors.affiliation: Private practice, Obere Bahnhofstrasse, CH 9500, Wil, Switzerland. praxis.beer@bluewin.ch
authors.forename: Karsten
authors.initials: K
authors.lastname: Beer
authors.forename: Martin
authors.initials: M
authors.lastname: Müller
authors.forename: Anna Marie
authors.initials: AM
authors.lastname: Hew-Winzeler
authors.forename: Adriano
authors.initials: A
authors.lastname: Bont
authors.forename: Philippe
authors.initials: P
authors.lastname: Maire
authors.forename: Xiaojun
authors.initials: X
authors.lastname: You
authors.forename: Pamela
authors.initials: P
authors.lastname: Foulds
authors.forename: Jessica
authors.initials: J
authors.lastname: Mårlind
authors.forename: Daniela
authors.initials: D
authors.lastname: Curtius
mesh_terms: D000328:Adult; D005260:Female; D000068717:Glatiramer Acetate; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage* / Q000009:adverse effects*; D007273:Injections, Intramuscular / Q000009:adverse effects; D007279:Injections, Subcutaneous / Q000009:adverse effects; D016899:Interferon-beta / Q000008:administration & dosage* / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy*; D010455:Peptides / Q000008:administration & dosage / Q000009:adverse effects*; D015995:Prevalence; D016903:Drug Monitoring
chemical_list: D007155:Immunologic Factors; D010455:Peptides; D000068717:Glatiramer Acetate; D016899:Interferon-beta
references.citation: Mult Scler. 2005 Jun;11(3):306-9
references.pmid: 15957512
references.citation: Mult Scler. 2005 Feb;11(1):46-50
references.pmid: 15732266
references.citation: Neurology. 2003 Aug 26;61(4):551-4
references.pmid: 12939437
references.citation: Neurology. 2002 Nov 26;59(10):1496-506
references.pmid: 12451188
references.citation: Lancet. 2002 Apr 27;359(9316):1453-60
references.pmid: 11988242
references.citation: Lancet Neurol. 2009 Oct;8(10):889-97
references.pmid: 19729344
references.citation: J Neurol Neurosurg Psychiatry. 2003 Dec;74(12):1689-92
references.pmid: 14638892
references.citation: Can J Neurosci Nurs. 2008;30(4):18-25
references.pmid: 19146204