title: Frequent paracetamol use and asthma in adults.
abstract: BACKGROUND
  The pulmonary antioxidant glutathione may limit airway inflammation in asthma. Since paracetamol (acetaminophen) depletes the lung of glutathione in animals, a study was undertaken to investigate whether frequent use in humans was associated with asthma.
  
  
  METHODS
  Information was collected on the use of analgesics as part of a population based case-control study of dietary antioxidants and asthma in adults aged 16-49 years registered with 40 general practices in Greenwich, South London. The frequency of use of paracetamol and aspirin was compared in 664 individuals with asthma and in 910 without asthma. Asthma was defined by positive responses to questions about asthma attacks, asthma medication, or waking at night with shortness of breath. The association between analgesic use and severity of disease amongst asthma cases, as measured by a quality of life score, was also examined.
  
  
  RESULTS
  Paracetamol use was positively associated with asthma. After controlling for potential confounding factors the odds ratio for asthma, compared with never users, was 1.06 (95% CI 0.77 to 1.45) in infrequent users (<monthly), 1.22 (0.87 to 1.72) in monthly users, 1. 79 (1.21 to 2.65) in weekly users, and 2.38 (1.22 to 4.64) in daily users (p (trend) = 0.0002). This association was present in users and non-users of aspirin and was stronger when cases with more severe disease were compared with controls; amongst cases increasing paracetamol use was associated with more severe disease. Frequency of aspirin use was not associated with asthma when cases as a whole were compared with controls, nor with severity of asthma amongst cases. Frequent paracetamol use was positively associated with rhinitis, but aspirin use was not.
  
  
  CONCLUSIONS
  Frequent use of paracetamol may contribute to asthma morbidity and rhinitis in adults.
authors.affiliation: Department of Public Health Sciences, Guy's, King's and St Thomas' School of Medicine, London SE1 3QD, UK. seif.shaheen@kcl.ac.uk
authors.forename: S O
authors.initials: SO
authors.lastname: Shaheen
authors.forename: J A
authors.initials: JA
authors.lastname: Sterne
authors.forename: C E
authors.initials: CE
authors.lastname: Songhurst
authors.forename: P G
authors.initials: PG
authors.lastname: Burney
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000009:adverse effects*; D000293:Adolescent; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000009:adverse effects*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D001241:Aspirin / Q000008:administration & dosage; D001249:Asthma / Q000209:etiology*; D016022:Case-Control Studies; D005978:Glutathione / Q000172:deficiency*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D006113:United Kingdom
chemical_list: D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000082:Acetaminophen; D005978:Glutathione; D001241:Aspirin