title: Efficacy of increased gentamicin concentration for intratympanic injection therapy in Ménière's disease.
abstract: OBJECTIVE
  Update of ongoing case series of intratympanic gentamicin use in intractable Ménière's disease. Comparison of the treatment results of two gentamicin concentrations: 30 mg/ml and 40 mg/ml.
  
  
  METHODS
  Retrospective case-matched review of an ongoing protocol.
  
  
  METHODS
  Ambulatory visits in an office setting.
  
  
  METHODS
  Eighty-seven patients were included in this study according to the 1995 guidelines of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) for reporting treatment results of Ménière's disease.
  
  
  METHODS
  Intratympanic injection of a buffered gentamicin solution (30 mg/ml) was used in 44 patients (Group 1) in years 1992 to 1995. Stock gentamicin solution (40 mg/ml) was used in 43 patients (Group 2) in years 1996 to 1999. Treatment was titrated for each patient, and the hearing was strictly monitored. The endpoint of treatment was the complete cessation of vertigo spells.
  
  
  METHODS
  Hearing results, vertigo control scores, and ice water caloric testing responses were analyzed after 24 months of follow-up. Thirty-two patients from each group were selected for case-matched statistical analysis.
  
  
  RESULTS
  Four or fewer gentamicin injections were used in 70% of Group 1 patients and 96% of Group 2 patients. In Group 1, vertigo control was achieved in 81% of patients, and the hearing remained the same or was improved in 68% of patients. In Group 2, vertigo control was achieved in 72% of patients, and the hearing remained the same or was improved in 81% of patients. Treatment was aborted in four patients of Group 2 for early reversible hearing loss, and 31 of 39 patients (79%) who completed the protocol experienced lasting vertigo control. There was a trend for longer-lasting vertigo control in the Group 2 patients.
  
  
  CONCLUSIONS
  It was concluded that increasing the gentamicin concentration to 40 mg/ml probably produces similar rates of vertigo control as those of the lower dose, at least initially, but requires fewer injections. The higher dose did not increase the risk of hearing loss if treatment was stopped at the first indication of injury. A larger study is needed to confirm the trend of improved long-term hearing results in patients treated with the 40 mg/ml solution.
authors.affiliation: Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
authors.forename: Ashraf Saad
authors.initials: AS
authors.lastname: Abou-Halawa
authors.forename: Dennis S
authors.initials: DS
authors.lastname: Poe
mesh_terms: D002150:Caloric Tests; D003638:Deafness / Q000139:chemically induced / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005839:Gentamicins / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D006309:Hearing / Q000187:drug effects; D006801:Humans; D007267:Injections; D008297:Male; D008575:Meniere Disease / Q000188:drug therapy*; D008875:Middle Aged; D009994:Osmolar Concentration; D012996:Solutions; D013997:Time Factors; D014432:Tympanic Membrane / Q000503:physiopathology*; D014717:Vertigo / Q000188:drug therapy
chemical_list: D005839:Gentamicins; D012996:Solutions