Response to Cochrane’s Review of Tamiflu Clinical Data

We fundamentally disagree with the overall conclusions of the Cochrane Acute Respiratory Infection Group’s (ARI) report on Tamiflu® (oseltamivir phosphate). We firmly stand by the quality and integrity of our data, reflected in decisions reached by 100 regulators across the world, including the U.S. Food and Drug Administration who have approved Tamiflu to reduce the severity and duration of flu symptoms.1

Note to user: the TAMIFLU indication statement and safety information are provided for reference at the end of this document.

As we’ve witnessed this flu season in the United States, influenza is a serious viral infection, which can result in death, even among otherwise healthy people.2 Cochrane’s report fails to take into account the totality of data available for Tamiflu including only 20 out of 77 clinical trials available to them and excluding real-world data from observational trials. The result is a misrepresentation of the safety and efficacy of an established influenza medicine, undermining consensus among global public health authorities.

We welcome third-party research, and are dedicated to sharing clinical data for our medicines in the interest of advancing science. However, we do not consider the ARI Group to be the final authority on the value of neuraminidase inhibitors. We believe it is important that public health bodies and influenza experts provide their opinion on this review alongside the totality of Tamiflu data, before any conclusions are drawn.

Patient-level data specifically made available to Cochrane has also not been taken into consideration for this review. This data allows greater precision in estimating clinical outcomes and has many statistical advantages,4 as compared to the study-level data used by Cochrane in their review.

In clinical trials Tamiflu has proven to be effective in reducing the severity and duration of flu symptoms when treatment is started early (within 48 hours of symptoms onset).1 Tamiflu has been reviewed and approved by regulatory authorities in over 100 countries and more than 38 million people in the U.S. have received a prescription for Tamiflu to treat or prevent influenza – including 15 million children.3 As with all of our medicines, we continuously monitor safety data related to the use of Tamiflu and this information is routinely provided to and reviewed by regulatory authorities.

We stand behind the abundance of data for Tamiflu as a treatment option recommended by public health agencies worldwide, including the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO).


Tamiflu is a prescription medicine used to treat the flu (influenza) in people 2 weeks of age and older who have had flu symptoms for no more than 2 days. Tamiflu can also reduce the chance of getting the flu in people 1 year and older.

Tamiflu does not prevent bacterial infections that may happen with the flu.

Tamiflu is not a substitute for an annual flu vaccination.

Patients must not take Tamiflu if they are allergic to oseltamivir phosphate or any of the ingredients in Tamiflu.

Important Safety Information

  • If patients have an allergic reaction or a severe rash with Tamiflu, they must stop taking it and contact their doctor right away. This may be very serious
  • People with the flu, particularly children and adolescents, may be at an increased risk of seizure, confusion, or abnormal behavior early during their illness
  • Patients must let their doctor know if they are pregnant, nursing, have heart problems, breathing problems, a weakened immune system (immunocompromised), kidney problems or other medical conditions as Tamiflu may not be right for them
  • Patients must also tell their doctor about any medications they are taking or if they’ve received a nasal-spray flu vaccine in the past two weeks
  • Patients should also tell their doctors:
    • If they have difficulty swallowing Tamiflu capsules
    • If they have a history of fructose (fruit sugar) intolerance. Tamiflu powder for oral suspension contains sorbital and may cause stomach upset and diarrhea in people who are fructose intolerant.
  • The most common side effects are mild to moderate nausea, vomiting, diarrhea and stomach pain

Report side effects to the FDA at (800) FDA-1088 or

Patients and caregivers may also report side effects to Genentech at (888) 835-2555.

For additional important safety information, please visit

About Genentech

Founded more than 40 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit