title: Effect of abrupt substitution of gadobenate dimeglumine for gadopentetate dimeglumine on rate of allergic-like reactions.
abstract: OBJECTIVE
  To evaluate the effect of abruptly substituting gadobenate dimeglumine for gadopentetate dimeglumine on allergic-like reactions.
  
  
  METHODS
  The institutional review board approved and waived patient consent for this HIPAA-compliant retrospective study. Allergic-like reactions related to gadolinium-based contrast media were assessed 2 years before and 3.5 years after gadobenate dimeglumine was substituted for gadopentetate dimeglumine. Reaction rates and severity were compared by using χ(2) tests, Fisher exact tests, odds ratios (ORs), and confidence intervals (CIs).
  
  
  RESULTS
  Allergic-like reactions (137 mild, 19 moderate, and six severe) occurred in 162 (0.15%) of 105 607 injections of gadolinium-based contrast media (gadopentetate dimeglumine, 31 540; gadobenate dimeglumine, 66 152; other, 7915). Gadobenate dimeglumine was associated with significantly more overall (0.19% [123 of 66 152] vs 0.08% [24 of 31 540]; OR, 2.4; 95% CI: 1.6, 3.8; P < .0001) and mild (0.16% [107 of 66 152] vs 0.06% [18 of 31 540]; OR, 2.8; 95% CI: 1.7, 4.7; P < .0001) allergic-like reactions than was gadopentetate dimeglumine. The reaction rate for gadobenate dimeglumine peaked (maximum per quarter, 0.38% [16 of 4262]; minimum per quarter, 0.07% [three of 4237]) in the 2nd year after it replaced gadopentetate dimeglumine (maximum per quarter, 0.10% [four of 4122]; minimum per quarter, 0.05% [two of 4222]) and then declined in the 3rd year. The final gadobenate dimeglumine reaction rate (last 3 quarters, 0.12% [17 of 14 387]) did not significantly differ from the original baseline reaction rate with gadopentetate dimeglumine.
  
  
  CONCLUSIONS
  After gadobenate dimeglumine was substituted for gadopentetate dimeglumine, a significant transient increase occurred in the frequency of reported allergic-like reactions that demonstrated a temporal pattern suggestive of the Weber effect (a transient increase in adverse event reporting that tends to peak in the 2nd year after a new agent or indication is introduced). © RSNA, 2012.
authors.affiliation: Department of Radiology, B2-A209P, University of Michigan Health System, 1500 E Medical Center Dr, Ann Arbor, MI 48103, USA. matdaven@med.umich.edu
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Davenport
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Dillman
authors.forename: Richard H
authors.initials: RH
authors.lastname: Cohan
authors.forename: Hero K
authors.initials: HK
authors.lastname: Hussain
authors.forename: Shokoufeh
authors.initials: S
authors.lastname: Khalatbari
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: McHugh
authors.forename: James H
authors.initials: JH
authors.lastname: Ellis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003287:Contrast Media; D004342:Drug Hypersensitivity / Q000453:epidemiology*; D057915:Drug Substitution; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008824:Michigan; D008875:Middle Aged; D009942:Organometallic Compounds; D018570:Risk Assessment; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine; D019786:Gadolinium DTPA