title: Usage patterns of over-the-counter phenazopyridine (pyridium).
abstract: OBJECTIVE
  Little is known about how the public uses formerly prescription medications that are available over-the-counter (OTC). This study examines whether consumers inappropriately use and substitute a recently widely distributed OTC urinary analgesic, phenazopyridine, for provider care.
  
  
  METHODS
  We conducted a cross-sectional survey of a stratified cluster random sample of OTC phenazopyridine purchasers (N = 434) in 31 Los Angeles retail pharmacies over 5 months. Recruited by shelf advertisements, participants were 18 years or older who purchased a phenazopyridine product. Each completed a 25-item self-administered anonymous questionnaire. Inappropriate use was defined as 1) having medical contraindications to phenazopyridine, or 2) not having concurrent antibiotic and/or provider evaluation for the urinary symptoms.
  
  
  RESULTS
  The survey response rate was 58%. Fifty-one percent of the respondents used OTC phenazopyridine inappropriately, and 38% substituted it for medical care. Multiple logistic regression analyses revealed that inappropriate use was correlated with having little time to see a provider (odds ratio [OR], 1.57; 95% confidence interval [95% CI], 1.26 to 1.96), receiving friend's or family's advice (OR, 1.25; 95% CI, 1.05 to 1.47), having prior urinary tract infections (OR, 0.49; 95% CI, 0.30 to 0.80), having used prescription phenazopyridine, (OR, 0.40; 95% CI, 0.25 to 0.63), and having back pain (OR, 0.34; 95% CI, 0.16 to 0.74). Similar correlates were found in those who substituted OTC phenazopyridine for provider care. Respondents with incorrect knowledge about phenazopyridine's mode of action had 1.9 times greater odds of inappropriate use and 2.2 times greater odds of substitution than those who had correct knowledge about this drug.
  
  
  CONCLUSIONS
  Inappropriate use of OTC phenazopyridine appears common. Increasing the public's knowledge about reclassified drugs may help to mitigate this problem.
authors.affiliation: University of California-Los Angeles, Departments of Family Medicine, Los Angeles, Calif. 90095, USA. cwshi@mednet.ucla.edu
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Shi
authors.forename: Steven M
authors.initials: SM
authors.lastname: Asch
authors.forename: Eve
authors.initials: E
authors.lastname: Fielder
authors.forename: Lillian
authors.initials: L
authors.lastname: Gelberg
authors.forename: Robert H
authors.initials: RH
authors.lastname: Brook
authors.forename: Barbara
authors.initials: B
authors.lastname: Leake
authors.forename: Martin F
authors.initials: MF
authors.lastname: Shapiro
authors.forename: Patrick
authors.initials: P
authors.lastname: Dowling
authors.forename: Michael
authors.initials: M
authors.lastname: Nichol
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000627:therapeutic use*; D001294:Attitude to Health; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D015141:Los Angeles; D008297:Male; D004366:Nonprescription Drugs / Q000627:therapeutic use*; D016017:Odds Ratio; D010621:Phenazopyridine / Q000627:therapeutic use*; D012651:Self Medication / Q000523:psychology / Q000706:statistics & numerical data; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
chemical_list: D000779:Anesthetics, Local; D004366:Nonprescription Drugs; D010621:Phenazopyridine