Tamiflu: The Controversial Flu Medication
Introduction
Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. According to the Centers for Disease Control and Prevention (CDC), every year in the United States millions of people get the flu, hundreds of thousands are hospitalized, and thousands die from flu-related illnesses. To combat this disease, researchers developed a medication called Tamiflu, which has been on the market since the 1990s. But what is Tamiflu, and is it effective? This article will explore the history, controversy, and recent developments surrounding Tamiflu.
What is Tamiflu?
Tamiflu (oseltamivir phosphate) is an antiviral medication used to treat and prevent influenza A and B viruses. It works by inhibiting the neuraminidase enzyme, which is necessary for the virus to release itself from infected cells. By blocking this enzyme, Tamiflu can reduce the severity and duration of flu symptoms and possibly prevent complications such as pneumonia, bronchitis, or hospitalization.
Development and Approval
Tamiflu was developed in the late 1990s by Gilead Sciences and later marketed by Roche. It was approved by the U.S. Food and Drug Administration (FDA) in 1999 as a prescription medication for treating acute uncomplicated influenza in adults. In 2000, it was also approved for treating flu symptoms in children ages one year and older.
In 2005, after a global outbreak of H5N1 bird flu, also known as avian influenza, the WHO recommended stockpiling Tamiflu as a defense against a potential pandemic. Many countries followed suit and purchased large amounts of Tamiflu to prepare for a possible flu outbreak. According to the CDC, the U.S. Strategic National Stockpile contains more than 31 million doses of Tamiflu.
Effectiveness
The effectiveness of Tamiflu in treating and preventing the flu has been the subject of much debate and controversy. While some studies suggest that Tamiflu can reduce the duration of flu symptoms by one to two days and lower the risk of complications, others question whether it is effective at all.
A 2014 Cochrane review, which analyzed the results of 20 clinical trials involving 26,717 people, found that Tamiflu reduced the duration of flu symptoms by 21 hours compared to placebo, but did not significantly reduce the incidence of hospitalization or pneumonia. The review also raised concerns about the quality of the studies, the lack of access to raw data from Roche, and the potential for publication bias.
In 2012, the British Medical Journal (BMJ) published an article that accused Roche of withholding key clinical trial data on Tamiflu, claiming that the drug was not as effective as previously thought. The BMJ and Cochrane researchers led a campaign to obtain the data from Roche and conducted their own independent analysis. The meta-analysis, published in the BMJ in 2014, concluded that Tamiflu did not significantly reduce the incidence of hospitalization or complications and had a higher risk of side effects such as nausea and vomiting.
Roche, however, disputed the findings and argued that the review was flawed and did not take into account all the available data. In response to the criticism, Roche pledged to release all of its Tamiflu clinical trial data to researchers. In 2015, the Cochrane researchers conducted a new analysis based on the additional data and found that while Tamiflu still reduced the duration of flu symptoms, there was no evidence that it reduced hospitalization or complications. The researchers concluded that the needle has moved little since 2014, and the evidence remains weak.
Side Effects and Safety
Tamiflu is generally well-tolerated, but like any medication, it can cause side effects. The most common side effects of Tamiflu include nausea, vomiting, diarrhea, dizziness, headache, and cough. Some people may experience more severe side effects, such as allergic reactions, seizures, or hallucinations, but these are rare.
There have also been concerns about the safety of Tamiflu, particularly in children and adolescents. In 2006, the FDA issued a warning about the risk of neuropsychiatric side effects such as delirium, hallucinations, and self-harm in patients taking Tamiflu, particularly children. There have been reports of deaths and accidents associated with Tamiflu use, but it is unclear whether these were directly caused by the medication or other factors.
In response to these concerns, the FDA required Roche to add a warning to the Tamiflu label about the risk of neuropsychiatric side effects. Roche also updated the label to include information about the possibility of serious skin reactions and reduced efficacy in patients with influenza who have taken Tamiflu prophylactically.
Recent Developments
In the wake of the COVID-19 pandemic, there has been renewed interest in the use of antiviral medications such as Tamiflu to treat viral illnesses. However, the evidence on the effectiveness of Tamiflu in treating COVID-19 is limited, and it is not currently recommended as a treatment.
In October 2020, the FDA approved the emergency use of Tamiflu in certain hospitalized COVID-19 patients who are at risk for severe illness but not yet requiring ventilation or extracorporeal membrane oxygenation (ECMO). The emergency use authorization was based on limited clinical data and expert opinion, and Tamiflu should only be used under close medical supervision.
Conclusion
Tamiflu is a controversial medication that has been the subject of much debate and scrutiny. While Tamiflu has been shown to reduce the duration of flu symptoms by a small amount, the evidence on its effectiveness in preventing complications and hospitalization is weak. There are also concerns about the safety of Tamiflu, particularly in children and adolescents. Further research is needed to determine the benefits and risks of Tamiflu and to develop better treatments for influenza and other viral illnesses.
References
Centers for Disease Control and Prevention. (2020). Key facts about influenza (flu). https://www.cdc.gov/flu/about/keyfacts.htm
Food and Drug Administration. (1999). Tamiflu label. https://www.accessdata.fda.gov/drugsatfda_docs/label/1999/20919lbl.pdf
Food and Drug Administration. (2018). Tamiflu label. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/021087s059lbl.pdf
Rawson, T. M., Moore, L. S. P., & Zhu, N. (2020). Tamiflu and COVID-19: a possible role for neuraminidase inhibitors? The Lancet Respiratory Medicine. https://doi.org/10.1016/S2213-2600(20)30327-6
Roche. (2020). Tamiflu (oseltamivir phosphate). https://www.tamiflu.com/
The Cochrane Collaboration. (2014). Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD008965.pub4/full
Science Media Centre. (2014). Expert reaction to BMJ feature on Tamiflu. https://www.sciencemediacentre.org/expert-reaction-to-bmj-feature-on-tamiflu/
World Health Organization. (2005). WHO issues interim guidance for the use of oseltamivir for the prophylaxis and treatment of influenza. https://www.who.int/mediacentre/news/releases/2005/pr38/en/
What is Tamiflu?
Tamiflu, or Oseltamivir is an anti-viral drug developed and manufactured by Roche for the treatment of influenza. The drug works by inhibiting an enzyme found in host cells. That inhibition acts to prevent the release of new particles of the influenza virus from being released by the infected host cell. The drug is approved for use by individuals one year old and over.
Side Effects
Common side effects of Tamiflu include nausea, diarrhea, abdominal pain, and headache. The rarer and more severe side effects associated with the drug include hepatitis, rash anaphylaxis and Stevens-Johnson syndrome.
One disastrous side effect associated with Tamiflu are neuropsychiatric disorders associated with hallucinations and attempts to hurt oneself and cause harm to others. In 2007 Japan’s health ministry issued a warning about use by individuals between the ages of 10 and 19 after a number of incidents involving teenagers jumping from tall buildings after taking the drug. A study done by the health ministry later confirmed that teenagers who take Tamiflu are 54% more likely to exhibit abnormal behavior; including hallucinations, than those who did not take the drug.
Government Regulations
Between 2005 and 2006 the FDA received 103 reports, mostly Japanese, that indicated a higher risk of hallucinations than previously expected. Due to this the FDA required a label change on Tamiflu packets indicating the possible side effects could include hallucinations, delirium and other unusual behaviors. In its defense Roche has commented that of the massive amount of people who get influenza every year it is more likely that the flu itself is responsible for the hallucinations, not Tamiflu. Roche has recently lowered the recommended dosage of Tamiflu in half, from 12mg/ml to 6mg/ml, due in part to FDA reports.
Litigation
If you or someone you know has taken Tamiflu and displayed adverse reactions including hallucinations and other abnormal behaviors you should stop the drug immediately. If you have been injured do to actions taken while on Tamiflu or you have suffered severe side effects including Stevens Johnson disease then you should consult an attorney about possible legal action against Roche. In an injury action it could be determined that Roche should have known that a high dose of Tamiflu might lead to adverse reactions. The recent decrease in dosage is circumstantial evidence of this.
