In 2018, the parents of a six-year-old girl told CBS News Texas that their daughter had hallucination and attempted to climb out of her second-story bedroom window after taking Tamiflu—a drug approved in 1999 to shorten the duration of flu. Her mother managed to grab her and pull her back inside just in time. An emergency physician later explained that the little girl was likely hallucinating—a rare psychiatric side effect of the antiviral medication.
This was not an isolated incident.
In 2020, Colorado mother Jennifer Humeny realized something was very wrong after giving her daughter a dose of Tamiflu. Even though her daughter had taken the medicine previously with no adverse effects, this time, the young girl started screaming and crying that she felt as though she was “floating in the air” above her couch, her mother told a local news organization. When Humeny’s daughter stopped taking the medication, her hallucinations ceased, though it’s unclear whether the medication caused her experience.
When her daughter contracted another severe case of influenza in 2021, Ms. Humeny and her doctor decided the expected benefits of Tamiflu were worth the risk of adverse symptoms. This time, her daughter experienced no psychiatric side effects.
In 2020, Sarah Wells, a mother in Central Point, Oregon, reported to her local news station that her 9-year-old son, Carder, experienced hallucinations while taking Tamiflu. The situation escalated to the point where she had to take him to the emergency department. She even shared a short video of the incident with the news station.
A quarter-century after the US Food and Drug Administration (FDA) approved Tamiflu to treat influenza, researchers still don’t know whether psychiatric side effects like these, more common in children than adults, are caused by the drug or the disease it’s meant to treat.
Tamiflu Side Effects: How Common Are Hallucination and Psychiatric Reactions?
The prevalence of psychiatric side effects associated with Tamiflu is not clear, though they’re thought to be seen more frequently in young patients. Complicating matters is the fact that influenza itself can also cause hallucinations in some people, particularly children under 10 years of age.
A 2023 study using the Tennessee Medicaid database found that the risk of neuropsychiatric events in children and adolescents with influenza was minimal, regardless of whether they were administered Tamiflu – 51 events per 100,000 person-weeks of having the infection. This measurement accounts for the total time each participant was at risk of experiencing a serious neuropsychiatric event, such as hallucinations, confusion or seizures.
Taking the medication did not increase an individual’s risk of neuropsychiatric events, the study found, but having preexisting neurological or psychiatric disorders did. Adolescents were also more likely to experience these symptoms than children.
When it comes to the specific reasons for these rare psychiatric events, researchers hypothesize that they might occur with Tamiflu through a variety of mechanisms. One hypothesis suggests that the drug may interfere with monoamine oxidase-A, a compound that breaks down certain chemicals brain cells use to communicate—including serotonin, dopamine, and norepinephrine. This leaves more of these chemicals available in your brain for longer periods of time.
How Does Tamiflu Work?
Tamiflu (oseltamivir) is an antiviral medication designed to lessen the symptoms of influenza.
When an influenza virus infects your body, it enters your cells and uses them to make copies of itself. Tamiflu doesn’t kill the virus outright, but it stops viral replication by blocking an enzyme called neuraminidase. Taking Tamiflu within the first two days of infection helps lower the amount of influenza virus in your body, so you recover about a day faster and may not get as sick. However, the drug is also known to cause side effects such as nausea, vomiting, headaches and kidney problems.
Experts debate just how effective Tamiflu is in preventing severe outcomes from flu. A review of clinical trials published in 2014 suggests that Roche, the drug’s manufacturer, may have engaged in selective reporting that made Tamiflu appear more effective than it really is.
The FDA’s Stance on Tamiflu Psychosis
Currently, Tamiful has a warning on its label noting the risk of neuropsychiatric events, but this warning wasn’t always present.
In 2005, Tamiflu was prescribed extensively in Japan. In fact, Roche, the drug’s manufacturer, told the New York Times in that same year that out of 13 million Tamiflu prescriptions for children worldwide, an astonishing 11.6 million were in Japan. This liberal usage started to change, however, when the country reported that 12 children had died after taking the medication and 31 had experienced delirium, abnormal behavior or hallucinations.
The FDA convened a meeting in November 2005 to discuss these psychiatric side effects of Tamiflu. The agency decided to continue monitoring side effect reports for two years, before revisiting the topic.
In 2007, the FDA reported its findings to the Pediatric Advisory committee, which concluded that it could not determine whether the psychiatric side effects were caused by the drug or the illness itself. But erring on the side of caution, it recommended that the drug label include a warning regarding the possibility of confusion and abnormal behavior in patients of all ages.
More recent studies have failed to find an association between the use of Tamiflu and serious psychiatric events such as suicide attempts in pediatric patients.
What To Ask Your Pediatrician About Tamiflu and Hallucination
If you’re a parent or caregiver weighing the risks and benefits of giving your child Tamiflu this cold and flu season, consider asking your pediatrician these key questions:
- How much will Tamiflu help my child in this specific case? Are we getting it early enough to make a difference?
- Is my child at risk of dangerous outcomes of the flu if they don’t take Tamiflu?
- Does my child have any risk factors increasing the likelihood that they might experience hallucinations or other dangerous side effects?
