The FDA has issued a Public Health Alert to notify prescribers and pharmacists about potential dosing errors with Tamiflu oral suspension (oseltamivir, from Roche). Healthcare providers usually write prescriptions for liquid medicines in milliliters (mL) or teaspoons. Tamiflu, however, is dosed in milligrams (mg). The dosing dispenser packaged with Tamiflu has markings only in 30mg, 45mg, and 60mg. The FDA has received reports of errors where dosing instructions for the patient do not match the dispenser.

Healthcare providers should write dosing instructions in milligrams if the dosing dispenser provided with the drug is in milligrams. Prescribing Tamiflu oral suspension in teaspoons should be avoided; if a prescription is written in teaspoons, the pharmacist should convert the volume to milliliters. Pharmacists should ensure that the units of measure on the prescription instructions match the dosing device provided with the drug. If the prescription specifies administration using milliliters, the accompanying Tamiflu dispenser should be discarded and replaced with a measuring device (eg, syringe) calibrated in milliliters.

Tamiflu is indicated for the treatment of uncomplicated acute illness due to influenza infection in patients ≥1year of age who have been symptomatic for ≤2days and for the prophylaxis of influenza in patients ≥1year of age.

For more information visit www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm183714.htm.