FDA Warns Doctors and Parents About Dosage Discrepancy for Liquid Form of Tamiflu

By September 30, 2009 Drug Safety

As a dangerous drug attorney, I was very interested to see a series of warnings from the U.S. Food and Drug Administration about the drug Tamiflu. Tamiflu (oseltamivir) is an antiviral drug that fights the flu; it has been in the news recently because of its use to fight the H1N1 virus, also known as the swine flu. The FDA warning is not about the efficacy of the drug, but about its dosage in liquid form, which is intended for children. The prescription labeling information for Tamiflu is generally given in teaspoons or milliliters (by volume), the FDA said, but the dosing dispenser that comes with the drug is marked in milligrams (by weight). This can confuse parents and may lead to a toxic overdose or an underdose that can’t protect the child.
The discrepancy was first revealed in a letter published in the New England Journal of Medicine Sept. 23, WebMD reported Sept. 25. One of the authors of that letter was Kara Jacobson, a health researcher at Emory University. Jacobson’s six-year-old daughter was prescribed Tamiflu for H1N1, but her prescription was for three-fourths of a teaspoon twice a day. Because the dispenser was measured in milligrams, Jacobson and her husband, a doctor, had to track down and solve the equations to translate their daughter’s dosage, a process that took thirty minutes. Many other families wouldn’t have the awareness to identify that problem or the time and resources to solve it, Jacobson and her co-authors warned in their letter.
Both the FDA and Tamiflu’s manufacturer, Roche, have asked doctors to write their prescriptions in milligrams. They also asked parents and caregivers to be aware of the problem and if necessary, replace the included dosing dispenser with a syringe or other measuring device that uses milliliters. The FDA’s public health alert includes a chart giving the recommended dosage in both milligrams and milliliters according to the child’s weight.
The consequences of an incorrect dose can be serious. An overdose of Tamiflu is literally toxic; parents are advised to call a poison control center if they believe their children have been overdosed. Rare but serious adverse effects of Tamiflu can include liver problems, cardiac arrhythmia, seizure, aggravation of diabetes and a life-threatening skin condition called Stevens-Johnson syndrome. Meanwhile, an underdose of Tamiflu can make the drug ineffective, which puts the patient at risk for the worst symptoms of H1N1, including acute respiratory distress that leads to death in about half of those affected. While scientists still don’t fully understand the disease, children may be at special risk from the flu because studies show they don’t have the antibodies older people have.
As a defective prescription drug lawyer, I am happy to see that this problem was addressed before any reported cases of serious side effects from Tamiflu. Busy working parents with no special scientific or math training may not even notice the problem (especially since it uses the metric system), and if they do, it doesn’t seem likely that they’d come up with the equation Jacobson used. Thanks to worries about H1N1 spreading among children, the drug has sold so well that pharmacies briefly ran out of it, so there’s a lot around. With millions of parents stockpiling Tamiflu for use as a prophylactic, it’s not hard to imagine that a few might make mistakes that could seriously harm their children — with the best of intentions.


Carey, Danis & Lowe helps patients and families that were seriously harmed by a defective prescription drug or a manufacturer’s failure to warn about a serious danger posed by its product. Drug makers have a legal obligation to offer us safe products, and that includes products whose dosing instructions are not so unreasonably confusing that they could harm the ones we love. When someone is hurt because a manufacturer failed in that duty, these victims and their families have the right to hold manufacturers legally liable for their actions. Our pharmaceutical liability attorneys help victims of dangerous medications sue drug makers for full compensation for their injuries, including compensation for all past and future medical costs as well as physical injuries, pain and suffering.
If you or your child became ill because of unreasonably confusing instructions for Tamiflu or another prescription medication, you should talk to the Lowe Law Firm for more information on your legal rights. To set up a consultation at absolutely no charge or risk, please contact us online or call 1-877-678-3400 toll-free from anywhere in the U.S.