1.15.2013

Poor Tools Available For Fighting Seasonal Flu

Image Credit: Tamiflu
Influenza this year has reached epidemic proportions - now widespread in almost all 50 states and overwhelming hospital resources on the East Coast. 

Over at National Geographic, Carl Zimmer points out that, while the flu comes back and kills half a million people a year, it is pretty incompetent as far as epidemics go - unfortunately, our tools to respond are worse.
The fact that this year’s seasonal flu has overwhelmed us (shutting down some hospitals, in fact) doesn’t bode well for the inevitable moment some time in the future when we do come face to face with a much meaner flu strain.
The trouble lies not just in our creaky hospital system, but in the weapons we have on hand. There’s a flu vaccine, thank goodness, but it’s only about62% effective. Making matters worse, well under half of Americans get vaccinated each year. If you get sick, doctors don’t have a lot of options for treatments. 
Indeed, the other night I asked a provider if she wanted a flu swab. "Why," she said. "It doesn't change how we are going to treat it."

There are of course antiviral drugs on the market. Tamiflu being the most available drug. It is given out quite readily to anyone who demands it from their doctor and is even being used as prophylaxis after influenza exposure. 

How effective is Tamiflu? The joke around the hospital is that if you get the flu, it will be gone in two weeks. IF you take Tamiflu, it will be gone in 14 days. Actually, one study found that the duration of the disease symptoms is reduced on average of 20 hours. Moreover, in most otherwise healthy patient populations, using the drug caused little reduction in hospitalization or complications when compared with placebo in several studies.

So what's the harm? Well, there are side effects and adverse events that have been reported. Just about every drug -- including placebo if you coach for it -- has listed side effects of nausea, vomiting and abdominal pain. However, it is not often that you see this warning on a label:
Neuropsychiatric events: Patients with influenza, including those receiving
TAMIFLU, particularly pediatric patients, may be at an increased risk of
confusion or abnormal behavior early in their illness. Monitor for signs of
abnormal behavior. (5.2)
What kinds of confusion or abnormal behavior? Japanese cases involving abnormal behavior including a handful of deaths in pediatric patients lead regulators there to institute restrictions on prescribing the drug to those between the ages of 10 and 19 starting in 2007. 

Neurological and psychological disorders were listed as possible side effects including impaired consciousness, abnormal behavior and hallucinations. Convulsions,  seizure like activity and neurological symptoms such  delirium, hallucinations, confusion, abnormal behavior, convulsions, and encephalitis. have been reported as well, but infrequently given the widespread use of the drug.

So do we have underreporting of adverse events due to all the other factors involved in a patient suffering from a viral illness, or are these neurological side effects just so rare that it is hard to establish a causal relationship.

Still, a busy flu season has renewed the hype and demand for the only drug out there indicated for seasonal flu. Moreover, the company that makes it still refuses to release full data from the trials - which is suspicious.

Further reading: (See: The Myth of Tamiflu: Five Things You Should Know ) and the British Medical Journal's Open Data Campaign. 

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