Abstract
Abstract: :
Purpose: Mercury-based preservatives, such as thimerosal and phenylmercuric acetate, have been used in ophthalmic, otic, nasal, topical, and injectable medicines. Manufacturers removed thimerosal from pediatric vaccines (which contained 12.5 to 25 µg of mercury) due to a theoretical potential of developmental neurotoxicity from organomercurials. The Institute of Medicine's Immunization Safety Review Committee concluded that there is inadequate evidence to support a causal relationship between thimerosal exposure from childhood vaccines and neurodevelopmental disorders, but due to the theoretical possibility of risk urged that "full consideration be given to removing thimerosal from any biological product to which infants, children, and pregnant women are exposed." We investigated the mercury content of ophthalmic medications and the availability of alternate mercury-free medications which can be used in children and pregnant women. Methods: An outdated list of mercury-containing drug and biologic products was obtained from the Center for Drug Evaluation and Research of the U.S. Food and Drug Administration. Using this list as a starting point, the authors investigated the mercury content of ophthalmic medications currently available in the United States through personal communications with manufacturing companies. Results: Fourteen ophthalmic medicines and one soft contact lens cleaner sold in the United States contain mercury-based preservatives. The amount of mercury exposure from a treatment course with these medications of QID for 7 days (as an example) ranges from 1.87 µg to 70 µg. The mercury content of a full bottle or tube of these medications ranges from 16.7 µg to 500 µg. For each mercury-containing medication, mercury-free equivalent medications were identified. Conclusions: There is a general trend to remove mercury-based preservatives from medications as a precaution to reduce mercury exposure of infants, children, and breastfeeding and pregnant women. For these patient groups, until more information is available we caution ophthalmologists to avoid mercury-containing ophthalmic medicines and to use readily available mercury-free alternatives.
Keywords: pharmacology • drug toxicity/drug effects