Current Treatment of Respiratory Viruses - More Homilies

With Permission: SIB Swiss Institute of Bioinformatics,
Philippe Le Mercier, ViralZone.

My Facebook feed got me going today.  I get the Mayo Clinic feed since I consider their clinical care and some of their research to be the best in the world.  Of course social media is much less rigorous and sometimes it comes down to just advertising and promotion.  That was my assessment of the link to this document this morning.  It is a business document that purports to give advice on how to decrease your chances of a respiratory infection this winter.  Some of that advice is given by a Mayo Clinic Infectious Disease specialist and a Cleveland Clinic family physician.  There was one number I had not seen before and that is the Number Needed to Treat (NNT) for the flu vaccine is 40.  Forty people need to be vaccinated to prevent one case.  The advice is the usual set of homilies about respiratory infections including get the flu vaccination, wash your hands, sneeze into your sleeve, take care of yourself and stay home of you are sick.  In other words, there is no way in hell that you are not going to get sick at least once this winter.

Our continued 1950's approach to viral infections remains a mystery to me.  Certainly there are technical problems with trying to design vaccines for over 200 viruses that can cause the common cold.  But the reality is, vaccine design for influenza virus - easily the most lethal of these viruses is obviously not so hot.  As far as I know, vaccines for the most common of the cold viruses - Rhinovirus - is non-existent.  Anti-viral medications for respiratory viruses are more controversial.  Looking at the most popular one Tamiflu or oseltamivir.  The NNT to prevent one death may be 1,800 - 3,200.  The NNT to prevent one hospitalization may be 97 to 142 depending on criteria.  The NNT group suggests somewhat better NNTs of 36 and 83 for preventing a culture positive case of influenza and preventing pneumonia respectively.    Contrast that with the NNT for antidepressants of 5-10 as determined by Leucht, et al (2) in their comparison to other medications for various medical conditions.  And you thought antidepressants were ineffective?

Infectious disease respiratory virus research is a goldmine for all of the Luddites out there.  There are a number of web sites that provide free access to just about everything you ever wanted to know about every virus known to man.  The viral particle shown at the top of this page is the order that contains Rhinoviruses one of many common cold viruses and one of the viruses that may be responsible for the expression of asthma in predisposed individuals or exacerbations of asthma in asthmatics who are asymptomatic.   This illustration is from the ViralZone, one of many free online databases with detailed information about the molecular biology and genetics of viruses.  If I was an aspiring Luddite wanting to be provocative about the field of medicine being stuck in the 1950s despite the availability of all of this advanced information - this would be a logical place to start.

In previous posts here I have also critiqued the lack of attention given to environmental approaches to respiratory viruses and the fact that the airborne nature of some of these viruses is not acknowledged - possible because airborne viruses are not contained by hand washing and other direct contact techniques.  It s well know that viruses can be collected in the heating and air conditioning systems of public buildings and that altering the humidity and air flow characteristics in those buildings can change the viral concentrations in the air.  Whenever I have mentioned this to the administrators of buildings where repeated respiratory epidemics swept through the staff - I got the same response that I received from an airline after I reported a severe respiratory infection after one of their flights: "We are really sorry that you had flu-like symptoms after your flight and look forward to your future comments to help us improve our service."

What?!

 Time to get serious about respiratory infections and come up with some effective interventions.  Effective medication to prevent viral replication and spread in the infected and to create barriers to infection would be ideal and so would environmental methods to reduce the infection rate.  Considering the strong incentives in America to work while sick and considering that the average worker is going to get 2 to 3 respiratory infections per year that can last up to 3 weeks in duration means that very few of us and the patients that we treat are not going to be exposed and infected.  With the current advanced knowledge of the pathogens and modern heating and air conditioning systems it seems like a lot more could be done right now.


George Dawson, MD, DFAPA


References:

1:  Postma MJ.  Re: Tamiflu: NNT to prevent a pandemic flu death may be a million.  BMJ 2005; 331:1203.

2:  Leucht S, Hierl S, Kissling W, Dold M, Davis JM. Putting the efficacy of psychiatric and general medicine medication into perspective: review of meta-analyses. Br J Psychiatry. 2012 Feb;200(2):97-106. doi: 10.1192/bjp.bp.111.096594. Review. PubMed PMID: 22297588.


Attributions:

Graphic at the top of this post is courtesy of: SIB Swiss Institute of Bioinformatics, Philippe Le Mercier, ViralZone.  http://viralzone.expasy.org/  licensed via Creative Commons Attribution- NonCommercial 4.0 International License.

Homicide Debate Goes Further Off the Rails

Apparently broadcast news is about as reliable as the Internet these days.  I was watching an "expert" on the weekend discuss the connection between homicide and antidepressant medications.  He apparently believed that there was one.  I understand that Sanjay Gupta made a similar comment today on CNN.  The misinformation is flying out there.  There are several political interests that would like that statement to be true and they appear to be out in full force. What is the short answer to the association between antidepressants and homicide?  Who can you believe?

Well there is always the scientific approach and a review of the medical literature.  Admittedly the literature is a lot drier and less entertaining than Dr. Gupta.

There is also simple arithmetic   The American media like to give the impression that violent crime and homicide are at epidemic levels.  It is always a shock when people discover that in fact we are at a 30 year low:

The homicide rate has actually declined from 10.2 per 100,000 in 1980 to 5.0 per 100,000 in 2009.  What are the odds of that happening if a major new cause of homicide is being added at the same time (namely antidepressants).  How does that compare with antidepressant use?  A recent study estimated that from 1996 to 2005, the number of Americans older than 6 years of age in surveyed households who received at least one antidepressant in the year studies increased from 5.84% in 1996 to 10.12% in 2005.  From the table there was a 24% reduction in the homicide rate during a time that antidepressant use nearly doubled.  One in ten Americans received an antidepressant prescription   The authors of this study noted this trend was broad based and correlated with a lower percentage of people receiving psychotherapy.

But what does that tell us about the observation that antidepressants cause homicide?  Technically there is no current way to demonstrate causality from a negative correlation between homicide rates and the rate of people taking antidepressants.  A large scale significant negative correlation between antidepressant use and lethal violence over a 15 year period has already been reported in the Netherlands.

What about the commentator suggesting that the toxicology of homicide perpetrators shows that they can have psychiatric drugs present that explain their homicidal behavior.  In fact, a study looking at that issue showed that 2.4% of 127 murder-suicide perpetrators had toxicology that was positive for antidepressants.  That is a lower than expected rate of antidepressant use than in the general population.   In a study of elderly spousal homicide-suicide perpetrators, depression was seen as an antecedent to this act but none of the perpetrators tested positive for antidepressants.

Given these observations any claim that antidepressant or any psychiatric drug causes homicidal behavior needs to be backed up with some hard data.  I don't mean a series of cases reported by somebody to make a point and I don't mean a legal decision where lawyers and judges can pretend that scientific data do not exist and make a decision about what they hear in a court room.  I also do not mean listening to somebody claim that we will never know the real relationship until we conduct "prospective double blind placebo controlled studies" of homicidality as a medication side effect.  If it isn't obvious, that study would by definition be unethical and would not pass the scrutiny of any human subjects committee.

Anyone with potential homicidal thinking needs close supervision and treatment.  They may need inpatient treatment in a unit that specialized in treating homicidal thinking and behavior.  Any clinician working in these settings will tell you that the people being treated generally come in with aggressive and violent thoughts and behavior before they take any medication.  If they have positive toxicology associated with homicidal thinking it is generally alcohol or an illicit drug like cocaine or methamphetamine.  Anyone with this problem also needs close monitoring and management of medication side effects.  Antidepressants can cause agitation and restlessness.  There are some people who do not benefit from antidepressants.  In the case of persons with the potential for aggression and suicide the medication response may need to be determined in a controlled environment before they can be safely treated.  Like all medications antidepressants are not perfect medications and they need to be administered by an expert who can provide effective treatment while managing and eliminating any potential drug side effects.

George Dawson, MD, DFAPA