title: Do selected drugs increase the risk of lupus? A matched case-control study.
abstract: OBJECTIVE
  To investigate the association between risk of lupus and exposure to selected drugs implicated in risk of lupus in a number of case reports.
  
  
  METHODS
  In this matched nested case-control study we utilized primary care data from the UK General Practice Research Database recorded between 1987 and 2001. Cases with at least one medical code for systemic lupus erythematosus or drug-induced lupus in their computerized records were matched to controls without a medical code for lupus or any other autoimmune disorder. Using conditional logistic regression we computed odds ratios (OR) and 95% confidence intervals (CI) for risk of lupus associated with exposure to selected drugs.
  
  
  RESULTS
  There were 875 incident cases, of which 12% (n= 107) had evidence of a prescription for one or more of the suspected drugs, and 3632 matched controls. For some drugs, prescriptions were too uncommon to be able to estimate associated risk of lupus. Despite small numbers of exposed patients and low statistical precision we observed an increased risk of lupus for hydralazine (OR = 6.62, 95% CI 1.03, 42.74), minocycline (OR = 4.23, 95% CI 2.65, 6.75) and carbamazepine (OR = 1.88, 95% CI 1.09, 3.22). There was some indication that the effect of carbamazepine was restricted to women (P for interaction by gender = 0.047).
  
  
  CONCLUSIONS
  This study shows that even those drugs suggested by case reports as causing lupus cannot all be clearly shown to be associated, even in a very large population-based database. Our findings support causal relationships for carbamazepine, minocycline and possibly hydralazine. Overall, drugs do not seem to be a major cause of lupus.
authors.affiliation: Department of International Epidemiology, Amgen Ltd, Uxbridge Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: W Marieke
authors.initials: WM
authors.lastname: Schoonen
authors.forename: Sara L
authors.initials: SL
authors.lastname: Thomas
authors.forename: Emily C
authors.initials: EC
authors.lastname: Somers
authors.forename: Liam
authors.initials: L
authors.lastname: Smeeth
authors.forename: Joseph
authors.initials: J
authors.lastname: Kim
authors.forename: Stephen
authors.initials: S
authors.lastname: Evans
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hall
mesh_terms: D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D000927:Anticonvulsants / Q000009:adverse effects; D000959:Antihypertensive Agents / Q000009:adverse effects; D014150:Antipsychotic Agents / Q000009:adverse effects; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008178:Lupus Erythematosus, Cutaneous / Q000139:chemically induced* / Q000453:epidemiology; D008180:Lupus Erythematosus, Systemic / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D055553:Prescription Drugs / Q000009:adverse effects*; D012306:Risk; D012737:Sex Factors; D014665:Vasodilator Agents / Q000009:adverse effects
chemical_list: D000889:Anti-Arrhythmia Agents; D000900:Anti-Bacterial Agents; D000927:Anticonvulsants; D000959:Antihypertensive Agents; D014150:Antipsychotic Agents; D055553:Prescription Drugs; D014665:Vasodilator Agents