title: N-of-1 (single-patient) trials for statin-related myalgia.
abstract: BACKGROUND
  Statin-related myalgia is difficult to distinguish from other conditions causing myalgia and may often lead to statin discontinuation.
  
  
  OBJECTIVE
  To compare the effect of statin rechallenge with placebo in patients with prior statin-related myalgia and to determine whether patients resumed statin therapy after evaluating the results.
  
  
  METHODS
  N-of-1 trial with 3 double-blind, crossover comparisons separated by 3-week washout periods. (Clinicaltrials.gov: NCT01259791) SETTING: Tertiary care lipid clinic.
  
  
  METHODS
  Patients with prior statin-related myalgia with or without mild elevation of creatine kinase levels.
  
  
  METHODS
  Rechallenge with the statin that was previously associated with myalgia within 3 weeks of open-label use versus matching placebo.
  
  
  METHODS
  Weekly visual analogue scale (VAS) scores for myalgia and specific symptoms (VAS myalgia score and symptom-specific VAS score, respectively), pain interference scores, and pain severity scores were recorded during the 3-week periods when patients were receiving placebo or statin. The primary outcome was the VAS myalgia score (range, 0 to 100 mm).
  
  
  RESULTS
  Eight patients (mean age, 66 years [SD, 8 years]; 88% women, all with high 10-year Framingham cardiovascular risk) participated in n-of-1 trials. Seven patients completed 3 treatment pairs, and 1 completed 2 treatment pairs. For each n-of-1 trial, no statistically significant differences were seen between statin and placebo in the VAS myalgia score, symptom-specific VAS score, pain interference score, and pain severity score. Five patients resumed open-label statin treatment, with a median posttrial follow-up of 10 months.
  
  
  CONCLUSIONS
  Results are limited by the small sample size and cannot be extended to patients with longer onset of myalgia after statin initiation.
  
  
  CONCLUSIONS
  In selected patients with a history of statin-related myalgia whose symptoms are difficult to evaluate, n-of-1 trials may be a useful method for determining statin tolerability.
  
  
  BACKGROUND
  Western University, London, Ontario, Canada.
authors.forename: Tisha R
authors.initials: TR
authors.lastname: Joy
authors.forename: Alaa
authors.initials: A
authors.lastname: Monjed
authors.forename: Guang Yong
authors.initials: GY
authors.lastname: Zou
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hegele
authors.forename: Charlotte G
authors.initials: CG
authors.lastname: McDonald
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Mahon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000069059:Atorvastatin; D004311:Double-Blind Method; D005260:Female; D005464:Fluorobenzenes / Q000009:adverse effects* / Q000627:therapeutic use; D006538:Heptanoic Acids / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D006937:Hypercholesterolemia / Q000188:drug therapy*; D008297:Male; D063806:Myalgia / Q000139:chemically induced*; D011743:Pyrimidines / Q000009:adverse effects* / Q000627:therapeutic use; D011758:Pyrroles / Q000009:adverse effects* / Q000627:therapeutic use; D012107:Research Design; D000068718:Rosuvastatin Calcium; D013449:Sulfonamides / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D005464:Fluorobenzenes; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; D013449:Sulfonamides; D000068718:Rosuvastatin Calcium; D000069059:Atorvastatin