It's important to be aware of the possibility of dosing errors in young children who receive oseltamivir in oral suspension, physicians warned in a letter in the New England Journal of Medicine.
The letter describes the case of a 6-year-old diagnosed with pandemic influenza A(H1N1) and given a prescription for oseltamivir (Tamiflu). An oral dosing dispenser that accompanied the drug's package was marked in 30-, 45-, and 60-mg increments, but the label from the pharmacy listed the child's dose in volume — ¾ teaspoon by mouth twice daily.
The child's parents—one a primary care physician, the other one of the letter's authors—were able to determine the correct dose only after solving an equation to determine the milligram equivalent of a ¾-tsp dose (N. Engl. J. Med. 2009 Sept. 23 [doi: 10.1056/c0908840]).
“Most families and caregivers would not be able to identify or perform the cumbersome calculations required to administer Tamiflu safely to children,” wrote Dr. Ruth M. Parker of Emory University in Atlanta, and her colleagues.
This disparity in units of measure could lead to dosing errors, compromised treatment, or toxic effects, they wrote. “In the future, all measuring devices for use in children should be marked with volumetric doses (milliliters or teaspoons),” the authors stated.
The coauthors of the letter were Michael S. Wolf, Ph.D., MPH, of the Feinberg School of Medicine in Chicago; Kara L. Jacobson, MPH, of Emory University, and Dr. Alastair J.J. Wood of Symphony Capital in New York.
Dr. Wolf has received consulting fees from Abbott and Pfizer, and grant support from Ortho-McNeil Pharmaceuticals. Dr. Wood has served as a director of Oxigene Inc., and he has served as a consultant for international reinsurance companies.