Photo Credit –CDC PHIL
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A new study that appeared in the Proceedings of the Royal Society B yesterday, provides a fresh look at a topic I’ve written about several times in the past; the potential downsides of using antipyretic meds (ibuprofen, acetaminophen or paracetamol, etc) for flu-related fever.
While earlier studies have concentrated on the affects of these meds on the individuals taking them, this new study looks at the population-level impact of taking these fever-reducing meds during an influenza outbreak.
Fever is the body’s natural reaction to infection, and since most viruses have a narrow `comfort zone’, a spike in temperature can lower the amount of virus the host is carrying . .. and shedding. Another side effect of fever is that it makes you feel miserable, and so people with a fever are more likely to stay home, rather than go to work or school.
When you artificially reduce the fever, you not only give the virus a better environment in which to replicate, you are also more likely to go out and infect others. A double whammy.
While neither of these concepts is new, this study attempts to quantify the impact in terms of the virus’s R0 (R naught) or Basic Reproductive Number, and they calculate the use of fever suppression meds increases the number of annual cases by approximately 5%, resulting in more than 1,000 additional flu deaths each year in North America.
First, a link to the study, then some excerpts from the press release from McMaster University, after which I’ll be back with more.
Population-level effects of suppressing fever
David J. D. Earn, Paul W. Andrews and Benjamin M. Bolker
Abstract
Fever is commonly attenuated with antipyretic medication as a means to treat unpleasant symptoms of infectious diseases. We highlight a potentially important negative effect of fever suppression that becomes evident at the population level: reducing fever may increase transmission of associated infections.
McMaster University researchers find fever-reducing medications may aid spread of influenza
Hamilton, ON (Jan. 21, 2014) -- Contrary to popular belief, fever-reducing medication may inadvertently cause more harm than good.
New research from McMaster University has discovered that the widespread use of medications that contain fever-reducing drugs may lead to tens of thousands more influenza cases, and more than a thousand deaths attributable to influenza, each year across North America. These drugs include ibuprofen, acetaminophen and acetylsalicylic acid.
"When they have flu, people often take medication that reduces their fever. No-one likes to feel miserable, but it turns out that our comfort might be at the cost of infecting others," said lead author David Earn, an investigator with the Michael G. DeGroote Institute for Infectious Disease Research (IIDR) and professor of mathematics at McMaster University.
"Because fever can actually help lower the amount of virus in a sick person's body and reduce the chance of transmitting disease to others, taking drugs that reduce fever can increase transmission. We've discovered that this increase has significant effects when we scale up to the level of the whole population."
The study, published in the Proceedings of the Royal Society B today, was co-authored with McMaster professors Ben Bolker, of the departments of mathematics & statistics and biology and the IIDR, and Paul Andrews of the Department of Psychology, Neuroscience and Behaviour.
The authors caution that this work is preliminary, the data is incomplete and heterogeneous, and that more work needs to be done before concrete proposals regarding the use of these drugs can be made.
In a real world example of how fever-reducers can increase the public’s exposure to an influenza virus, in Vietnam Discovers Passengers Beating Thermal Scanners we looked at reports of people using fever reducing meds to evade airline passenger screening during the 2009 H1N1 pandemic.
I’ve also written about studies that suggest that the concurrent use of antipyretics may inhibit the immune response when receiving vaccines. In fact, it has even been theorized that one of the reasons that the elderly often develop less-than-robust immunity from the flu vaccine may be due to their frequent consumption of NSAIDs.
Several past blogs on this phenomenon include:
Anti-Inflammatory Meds And Vaccines
In a another story from 2011 - the American Academy of Pediatrics (AAP) released a report on the use of antipyretics in children, suggesting that we ought not over-treat fevers.
Clinical Report—Fever and Antipyretic Use in Children
Janice E. Sullivan, MD, Henry C. Farrar, MD,
ABSTRACT EXCERPTS
Fever in a child is one of the most common clinical symptoms managed by pediatricians and other health care providers and a frequent cause of parental concern. Many parents administer antipyretics even when there is minimal or no fever, because they are concerned that the child must maintain a “normal” temperature.
Fever, however, is not the primary illness but is a physiologic mechanism that has beneficial effects in fighting infection. There is no evidence that fever itself worsens the course of an illness or that it causes long-term neurologic complications.
And in early 2013, in Adding To A Feverish Debate, we looked at another study appearing in the Journal of Pediatrics on another possible (albeit, rare) adverse effect seen in a small number of young children with fever and dehydration at a hospital in Indiana who received treatment with NSAIDs.
A accompanying press release from Indiana University that warned the administration of NSAIDs to reduce fever may result in AKI - Acute kidney Injury – in young children.
Common anti-fever medications pose kidney injury risk for children
Sick children, especially those with some dehydration from flu or other illnesses, risk significant kidney injury if given drugs such as ibuprofen and naproxen, Indiana University School of Medicine researchers said Friday.
In an article published online Jan. 25 by the Journal of Pediatrics, Jason Misurac, M.D., and colleagues from IU and Butler University reported that nearly 3 percent of cases of pediatric acute kidney injury over a decade could be traced directly to having taken the common nonsteroidal anti-inflammatory drugs, or NSAIDs
None of this is designed to demonize a useful, and ubiquitous, class of drugs. But it is axiomatic that there is no such thing as a 100% safe, 100% benign drug – even those you can buy over the counter.
If there is a health benefit to be had, we must weigh that against the (usually very slight) risks of taking the these meds.
Although the jury is still out on most of these concerns, and more research is needed, there is an increasing body of evidence that suggests we might want to think twice before automatically reaching for fever reducers in the medicine cabinet.
