title: Multicenter trial: comparison of two different formulations and application systems of low-dose nasal midazolam for routine magnetic resonance imaging of claustrophobic patients.
abstract: OBJECTIVE
  To prospectively assess and compare two formulations and methods of administration of low-dose nasal midazolam for the treatment of claustrophobic patients undergoing magnetic resonance imaging (MRI) as part of a multicenter Phase III trial.
  
  
  METHODS
  In all, 108 consecutive adult claustrophobic patients were randomly assigned to one of two treatment groups (multidose group: MDG, unit-dose group: UDG). MDG encompassed 55 patients who received intranasally a 0.5% midazolam formulation into each nostril (total dose, 1.0 mg), whereas the 53 patients in UDG received a 1% midazolam formulation into only one nostril (total dose, 1.0 mg). This initial dose could be repeated once. Patient tolerance and anxiety were assessed using a questionnaire and a visual analog scale immediately before and after MRI. Image quality was evaluated using a five-point scale.
  
  
  RESULTS
  In all, 53/55 MR examinations (96%) with MDG and 52/53 (98%) with UDG were completed successfully. The dose of 1 mg had to be repeated significantly less often in UDG compared to MDG (4/53, 8% vs. 13/55, 24%; P = 0.003). The image quality of all MR examinations was rated good to excellent, and slightly better in UDG (P = 0.045).
  
  
  CONCLUSIONS
  Nasally applied low-dose midazolam is a patient-friendly solution to facilitate MRI of claustrophobic patients. The nasal spray of UDG is superior to that of MDG with a necessity of additional dosing.
authors.affiliation: Institute of Diagnostic Radiology, University Hospital Zürich, Zürich, Switzerland. franktschirch@yahoo.de
authors.forename: Frank T C
authors.initials: FT
authors.lastname: Tschirch
authors.forename: Katja
authors.initials: K
authors.lastname: Suter
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Froehlich
authors.forename: Ueli
authors.initials: U
authors.lastname: Studler
authors.forename: Andreas
authors.initials: A
authors.lastname: Nidecker
authors.forename: Boris
authors.initials: B
authors.lastname: Eckhardt
authors.forename: Jan
authors.initials: J
authors.lastname: Beranek-Chiu
authors.forename: Christian
authors.initials: C
authors.lastname: Surber
authors.forename: Dominik
authors.initials: D
authors.lastname: Weishaupt
mesh_terms: D000281:Administration, Intranasal; D016009:Chi-Square Distribution; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D008279:Magnetic Resonance Imaging / Q000523:psychology*; D008297:Male; D008874:Midazolam / Q000008:administration & dosage*; D008875:Middle Aged; D010698:Phobic Disorders / Q000188:drug therapy*; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D006993:Hypnotics and Sedatives; D008874:Midazolam