title: Prescription-acquired acetaminophen use and potential overuse patterns: 2001-2008.
abstract: BACKGROUND
  Food and Drug Administration advisory committees recently made some recommendations to address acetaminophen (APAP)-related toxicity.
  
  
  OBJECTIVE
  To study the proportion of APAP users potentially consuming APAP over the currently recommended dosage (4 g/day) and a toxic dosage (10 g/day). To explore the impact of substituting the APAP strength in combination prescriptions to 325 mg on potential APAP overuse patterns.
  
  
  METHODS
  Using the 2001-2008 pharmacy claims from IMS LifeLink Health Plans, APAP potential maximum daily dose (PMDD), potential cumulative dose, and potential average daily dose (PADD) were calculated annually for APAP users. The proportion of users with potential APAP use above 4 g/day and 10 g/day are reported. Analyses were repeated by substituting the maximum APAP strength in combination prescriptions to 325 mg. Ordinary least squares regression was used to detect linear trends in APAP use/overuse.
  
  
  RESULTS
  790 188 of 2 656 161 study subjects were prescribed APAP in one or more years from 2001 to 2008. 32.62% and 26.84% of the adult APAP users had a PMDD > 4 gm/day in 2001 and 2008 while 1.88% and 3.17% had a PMDD > 10 gm/day. If the maximum APAP strength in combination prescriptions was 325 mg, the proportion of APAP users with PMDD > 4 g would be 14.08% in 2001 and 13.67% in 2008, whereas the proportion of those with PMDD > 10 g would be 0.21% and 2.30%, respectively.
  
  
  CONCLUSIONS
  About one in four APAP users have a PMDD > 4 g/day, whereas 2-3% have a PMDD > 10 g based exclusively on prescription data, which is concerning. These proportions could reduce by over half if the maximum APAP strength in combination prescriptions is 325 mg. Additional monitoring of opioid prescription-patterns, physician and pharmacist cognizance in prescribing APAP-containing combination products, and dose-reduction strategies should be considered to reduce APAP overuse.
authors.affiliation: College of Pharmacy, Division of Pharmaceutical Evaluation and Policy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
authors.forename: Mugdha
authors.initials: M
authors.lastname: Gokhale
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Martin
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D016208:Databases, Factual / Q000706:statistics & numerical data; D004305:Dose-Response Relationship, Drug; D062787:Drug Overdose; D005260:Female; D006801:Humans; D007223:Infant; D016018:Least-Squares Analysis; D008297:Male; D055553:Prescription Drugs / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D012044:Regression Analysis; D012189:Retrospective Studies; D014481:United States; D014486:United States Food and Drug Administration; D055815:Young Adult
chemical_list: D018712:Analgesics, Non-Narcotic; D055553:Prescription Drugs; D000082:Acetaminophen