Overrated Medications Series: No. 5 Antibiotics for Sore Throats

I probably should have started with this topic in my series on overrated medications.  The number needed to treat, even if the patient has streptococcal pharyngitis, is about 1 million, higher still if they don’t have strep throat.  This makes the doctor using Crestor in primary prevention for patients with normal LDL and elevated hsCRP look like a genius.

It is well-known among physicians that antibiotics are over prescribed.  Several conditions come to mind for which antibiotics are often prescribed, but not needed: the common cold, allergic rhinitis, acute bronchitis (bacterial and viral) and acute pharyngitis, also known as the sore throat.

Why do physicians prescribe antibiotics unnecessarily?  First, I think there is a subtle pressure.  The patient made the appointment because they felt something needed to be done, namely an antibiotic prescribed.   When one isn’t prescribed they often complain.   In fact, it is not uncommon for a patient to present with a complaint that reads “I need an antibiotic.”   Secondly, the physician feels he has shortchanged the patient somehow if he assesses the situation and determines no treatment is needed.  The patient made an appointment, spent time away from home or work, and then the doctor does nothing.   But let’s not forget, no medication is without side effects and the prime principle of medical ethics is first, do no harm.

Now let’s tackle antibiotics and pharyngitis.  Antibiotics have routinely been prescribed for sore throats for over 30 years.  Antibiotics have definitely been prescribed for strep throat, but many doctors prescribe them for any sore throat.  The reason is that streptococcal pharyngitis is rarely followed by condition known as rheumatic fever and rheumatic fever is sometimes followed by permanent damage to the heart valves.  Treating streptococcal pharyngitis with an antibiotic, namely penicillin, will result in fewer cases of rheumatic fever.

How strong is the evidence?  If you are a physician, you might be surprised by what you read here.  When I discovered it I was very surprised.  I became aware of this information reading the excellent book Hippocrates Shadow by David H. Newman, M.D.  I recommend it to patients and physicians.

Our story begins in mid twentieth century Wyoming at Warren Air Force Base.  Here, according to Newman (1), during the 1940s and 50s military recruits suffered rates of rheumatic fever 1000 times the normal rate.   This presented an opportunity for research and the military physicians there discovered that penicillin reduced the rate of occurrence of rheumatic fever from 2% to 1% in recruits with strep throat.  They published their results in The Journal of The American Medical Association.  Only an excerpt is available without paying a fee.

Since only 2% of the recruits with strep throat developed rheumatic fever, 50 people had to be treated to impact one.  But, as Newman points out, Warren Air Force Base was suffering a rate of rheumatic fever 1000 times greater than normal.  And that is 1000 times normal for 1950.  Since then the incidence has declined further and Newman points out a current incidence of 0.1 per 100,000.

According to Newman, assuming physicians only treat strep positive sore throats, then 1 million antibiotics prescriptions will prevent 1 case of rheumatic fever and cause 2,400 potentially fatal allergic reactions, 100,000 cases of diarrhea and 100,000 rashes.

Some argue that rheumatic fever is in decline because of antibiotic use.  Newman argues otherwise and cites improved hygiene,   nutritional factors, decreased population crowding, improved preventive care and evolutionary changes in the bacterium.  His reference for this is here, but unfortunately only the abstract is available.

Thanks to David H. Newman and his excellent book for making this post possible.

1. Newman, David H., Hippocrates Shadow (New York:  Scribner, 2008) 112-115.