title: H1- and H2-receptor antagonists prevent histamine release in allergic patients after the administration of midazolam-ketamine. A randomized controlled study.
abstract: OBJECTIVE
  The prophylactic effects of H1- and H2-receptor antagonist against histamine release and clinical symptoms (e.g. skin reactions, hemodynamic changes) were examined in 80 allergic patients after the administration of midazolam-ketamine.
  
  
  METHODS
  We examined 80 allergic patients undergoing oral surgery.
  
  
  METHODS
  A prospective randomized controlled study was performed in four groups of 20 patients who received either hydroxyzine (H1-receptor antagonist), chlorpheniramine (H1-receptor antagonist), a combination of chlorpheniramine and famotidine (H1- and H2-receptor antagonist) or a placebo (control) as premedications. Venous blood samples were obtained before introduction as a control and 0.5, 1, 3, 5 min after the administration of midazolam-ketamine in order to measure the plasma histamine level. In addition, any observed hemodynamic changes were simultaneously recorded. The plasma histamine level was measured using the HPLC (high performance liquid chromatography) post-label system.
  
  
  RESULTS
  The patients who were treated with both chlorpheniramine and famotidine demonstrated a high level of basal plasma histamine compared to the patients who were treated by hydroxyzine alone (p < 0.05), and they also showed less histamine release and anaphylactoid reactions during midazolam-ketamine anesthesia. Allergic patients demonstrated a high percentage of eosinophils, with an average of 4.79 +/- 3.78%.
  
  
  CONCLUSIONS
  The administration of midazolam-ketamine in allergic patients demonstrated no significant problems. The combined premedication with chlorpheniramine and famotidine was thus found to have the most prophylactic effect against histamine release after the administration of midazolam-ketamine in allergic patients in spite of a high level of basal plasma histamine.
authors.affiliation: Department of Dental Anesthesiology, Faculty of Dentistry, Kyushu University, Fukuoka, Japan. kimura@dent.kyushu-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Adachi
authors.forename: K
authors.initials: K
authors.lastname: Kubo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019162:Anesthetics, Combined; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006632:Histamine / Q000097:blood; D006634:Histamine H1 Antagonists / Q000009:adverse effects / Q000494:pharmacology*; D006635:Histamine H2 Antagonists / Q000009:adverse effects / Q000494:pharmacology*; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D006967:Hypersensitivity / Q000503:physiopathology / Q000517:prevention & control*; D007649:Ketamine; D008297:Male; D008874:Midazolam; D008875:Middle Aged; D019647:Oral Surgical Procedures; D011446:Prospective Studies
chemical_list: D019162:Anesthetics, Combined; D018691:Excitatory Amino Acid Antagonists; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D007649:Ketamine; D006632:Histamine; D008874:Midazolam