The medical community should be made aware of the serious potential for dosing errors in children prescribed Tamiflu (oseltamivir) oral suspension, as illustrated in the case described below.

After the diagnosis of novel H1N1 influenza, a 6-year old received a prescription for Tamiflu (oseltamivir) oral suspension (12 mg per milliliter) at a dose of 3/4 teaspoon PO BID. However, the parents, one a primary care physician and the other one of the authors, had great difficulty determining the correct dose to administer to their child. The medication bottle was accompanied by a prepackaged syringe with markings of 30, 45, and 60 mg (Figure 1). The label attached by the pharmacy specified the dose in volume units ("3/4 teaspoonful") but the syringe provided only markings in mass units (milligrams). Despite the disparate directions, the parents were eventually able to determine the correct dose with the aid of 1 of 10 tables in the portion of the package insert intended for prescribers, not for parents. Specifically, they solved the following equation for the milligram equivalent of the 3/4-tsp dose: 5 ml (volume of a teaspoon)x0.75x12 mg per milliliter Tamiflu suspension=45 mg on the syringe.