MICROBIOLOGIC STUDIES OF MULTIPLE-DOSE CONTAINERS OF TRIAMCINOLONE ACETONIDE AND LIDOCAINE HYDROCHLORIDE

Abstract

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. 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. 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. 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.