Tamiflu with New Concentration In Distribution

July 21, 2011 11:01 AM

Manufacturer Genentech, working with FDA, has made changes to the influenza drug Tamiflu^® aimed to reduce chances of medication errors stemming from prescribing or dosing confusion. The concentration of Tamiflu has been changed from 12 mg/mL to 6 mg/mL, to avoid the medicine becoming frothy when shaken in order to ensure accurate measurement. Dosing devices have been updated to correspond with the units of measurement and product labeling provides dosage information based on the new concentration. In addition, compounding instructions for pharmacies have been revised to prepare a 6 mg/mL oral suspension from Tamiflu capsules in an emergency situation if the commercially manufactured Tamiflu for oral suspension is unavailable. Genentech plans to begin distributing Tamiflu in the new concentration in July 2011, and has initiated a voluntary take-back program for wholesale buyers, distributors, and pharmacies to remove the 12 mg/mL product from the marketplace.

An FDA Drug Safety Communication stresses that while there are no quality issues with the 12 mg/mL product, and it is still useable through its expiration date, “FDA encourages participation in the Take Back Program to limit the potential for product confusion.” In addition, FDA advises that it is important for health care providers “to be aware that a patient may potentially receive either concentration (6 mg/mL or 12 mg/mL) from their pharmacy during the next influenza season (2011-2012). Steps should be taken to avoid the potential for a medication error due to confusion between the two concentrations.”