Microbiologic studies of multiple-dose containers of triamcinolone acetonide and lidocaine hydrochloride.
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.
Bucher
Rodney S
RS
Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, USA.
Johnson
Mark W
MW
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*
D000779:Anesthetics, Local; D000900:Anti-Bacterial Agents; D005938:Glucocorticoids; D008012:Lidocaine; D014222:Triamcinolone Acetonide; D019905:Benzyl Alcohol