title: Microbiologic studies of multiple-dose containers of triamcinolone acetonide and lidocaine hydrochloride.
abstract: OBJECTIVE
  Reports of high endophthalmitis rates following intravitreal triamcinolone acetonide (TA) injection have raised concerns about safety. One possible risk factor is the use of multiple-dose containers. The purpose of this study was to determine whether there is a substantial risk of contamination of multiple-dose containers.
  
  
  METHODS
  Microbiologic Challenge Study: Suspensions of a known quantity of several microorganisms were placed in samples of TA to determine whether the preservative, benzyl alcohol 0.99%, is rapidly bacteriocidal. Simulated Clinical Use Study: After ten days of simulated clinical use of multiple-dose containers of TA and lidocaine hydrochloride 4%, samples were cultured. Additionally, samples from lidocaine containers in actual clinical use were cultured.
  
  
  RESULTS
  Microbiologic Challenge Study: Four of five challenge organisms demonstrated moderate growth, even after 24 hours of exposure to the benzyl alcohol preservative. Simulated Clinical Use Study: Simulated clinical use of multiple-dose containers of TA and lidocaine did not result in contamination, nor did actual clinical use of multiple-dose lidocaine containers.
  
  
  CONCLUSIONS
  No culture-proven contamination of multiple-dose containers in simulated or actual clinical use was found. However, TA suspension is capable of harboring viable bacterial and fungal pathogens. The use of multiple-dose containers of triamcinolone for intravitreal injections is therefore discouraged.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, USA.
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Bucher
authors.forename: Mark W
authors.initials: MW
authors.lastname: Johnson
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D019905:Benzyl Alcohol / Q000494:pharmacology; D015169:Colony Count, Microbial; D004340:Drug Contamination; D004349:Drug Packaging; D005658:Fungi / Q000187:drug effects / Q000254:growth & development*; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D008012:Lidocaine / Q000494:pharmacology*; D012307:Risk Factors; D014222:Triamcinolone Acetonide / Q000494:pharmacology*
chemical_list: D000779:Anesthetics, Local; D000900:Anti-Bacterial Agents; D005938:Glucocorticoids; D008012:Lidocaine; D014222:Triamcinolone Acetonide; D019905:Benzyl Alcohol