The practice of medicine and the science it’s based on, like most things, changes over time.
An excellent example of this comes by way of a reader’s thoughtful question that goes to the very heart of an issue we all face: What’s the proper way to take a course of antibiotics? Is it always through to the end until all the pills are gone, or should we stop when we begin to feel better?
The reader’s letter in full:
Here’s an antibiotic question I have. If you have a bacterial infection, the dr prescribed antibiotics. The label says to take all the pills. Usually a 10 day course. The thinking is that you don’t want to leave any of the “biotics” to live to attack another day. It makes sense. I have a friend who takes the drugs only until the symptoms go away. No problem. Could that be the better way? Give your own immune system a kick in the pants to fight off the bad bugs? That would support your own system. I don’t know which is right. I’ve always taken the full course (although I don’t take antibiotics unless I’m dying) and thought it made sense. My smart friend swears by her method. Who is right?
The “right” answer seems to depend on who you ask. Historically, the weight of opinion has been squarely on the side of taking each and every pill until they’re all gone, a view that’s still backed by our institutional heavyweights. The World Health Organization, for example, issued a news release last November in an effort to correct public misconceptions about antibiotics, saying, in part:
“… 64% of respondents believe antibiotics can be used to treat colds and flu, despite the fact that antibiotics have no impact on viruses. Close to one third (32%) of people surveyed [wrongly] believe they should stop taking antibiotics when they feel better, rather than completing the prescribed course of treatment.”
Similarly, the Mayo Clinic consumer health web site says: “It is tempting to stop taking an antibiotic as soon as you feel better. But the full treatment is necessary to kill the disease-causing bacteria.”
The US Centers for Disease Control and Prevention offer the same advice, with one caveat: “Never … stop taking an antibiotic early unless your healthcare professional tells you to do so.”
Which brings us to where we confront the issue: at our doctor’s office or with a hospital physician. And as we know they typically, if not always, warn us to complete the full course of antibiotics –– until recently.
Dr. Spellberg: That you have to keep taking your antibiotics even after you feel better “is an old wives’ tale.”
Meet infectious disease specialist Brad Spellberg, MD, clinician, professor of medicine, researcher, author of the book Rising Plague, and Chief Medical Officer of the LA County and USC Medical Center. He represents an emerging school of thought that says you should stop taking antibiotics when your symptoms disappear. In an interview with the science magazine Discover, he sums it up nicely:
“The science is clear. Every study that has been done comparing longer versus shorter antibiotic therapy has found shorter therapy just as effective. The issue of continuing therapy until all doses are done is an old wives’ tale. There’s no data to support it. You can’t make a cured patient better.”
Effectiveness, then, is one factor to consider on the question of how long to an antibiotic. But there’s another important factor in play here too: harm. Like all drugs, even aspirin, antibiotics come with unwanted side effects. So the more antibiotics you take the greater the chance you will experience some of them including, paradoxically, increasing your risk for infection down the road.
It goes like this. The majority of the antibiotics prescribed, like amoxicillin, for example, are “broad-spectrum”: they go after all the bacteria in you, not just the bug causing the problem. So whether you have a strep, staph, or E coli, infection, say, the antibiotic will eliminate it because it kills all susceptible bacteria, including — and here’s the rub — your “good” bacteria. These good bacteria operate in conjunction with your immune system to protect you from disease. So if you knock them out with an antibiotic and are then exposed to a disease-causing germ, your chances of that germ making you sick go up.
That’s the conclusion of infectious disease specialist Martin Blaser, MD, director of the Human Microbiome Program, researcher and professor of medicine at New York University, and author of the book Missing Microbes. As he candidly challenges: “Has any health-care professional ever told you that taking antibiotics would increase your susceptibility to infection?”
Dr. Blaser: The paradox of taking antibiotics is that they actually increase your risk of infection.
Where this increased susceptibility issue gets overlooked is its effect on kids. Early life is a vulnerable time and a critical period for development. Yet, cautions Blazer, “We have been using antibiotics as if there was no biological cost.” The average child in the United States, he says, receives 10 courses of the drugs by the age of 10, setting them up for such things as obesity, impaired metabolic function, and impaired bone growth, i.e., height. And the effects of antibiotics, his research shows, are cumulative: the more you take, the greater the risk of one or more of these “side effects.”
So, for how long should you take that antibiotic? For as short a time as possible, and for two reasons: short courses are just as effective as longer courses (Spellberg); and the more antibiotics you take the greater the chance that something will go wrong, including, oddly, the increased risk of infection (Blaser).
There’s a third and crucial point to consider, which is really the threshold question: Whether we should we even be taking an antibiotic in the first place. Antibiotics only work on infections caused by bacteria, not viruses. According to the CDC, infections caused by viruses include the stuff we all experience: colds, the flu, most sore throats, most coughs and bronchitis (“chest colds”), many sinus infections, and many ear infections — and for all these things, antibiotics have no role to play. So going after virus with an antibiotic would be like hunting bear with a fishing rod: in neither case will you get the job done, and in both cases you could get hurt.
Notice the CDC’s use of the words “most” sore throats, “many” sinus infections, and so on. Some sore throats, etc., are therefore caused by a bacterium for which an antibiotic should prove effective: but how do you distinguish a bacterial from a viral-based infection? The sure way is take a sample from the infected area and send it to the lab for analysis – which will take a few days – or, as is most often the case, your physician will exercise their clinical judgment to determine where the probabilities lie. And “lie” they might, because it is, after all, an exercise in professional guesswork.
So back to our reader’s question. It seems they both have valid points well-supported by the evidence. Recent clinical trials and the voice of leader’s in the field of infectious disease such as Brad Spellberg suggest that stopping antibiotics as soon as your symptoms disappear is where we’re headed. And the reader who said “I don’t take antibiotics unless I’m dying,” would have the support of everyone, especially Dr. Blazer and his colleagues.
The medical evidence, then, tells us 3 things: Be sure an antibiotic is the right tool for the job; if it is, a short course will be just as effective as a long course; and a short course will also minimize your risk of antibiotic harm, such as obesity or becoming more vulnerable to infection down the road.
Knowing all this, let’s see how it plays out in the real world.
You’re at your pediatrician’s office. Your 5-year old boy has come down with some kind of infection, again. Your doctor examines him and says in her opinion your child probably has a touch of bronchitis. She hands you a prescription for a broad-spectrum antibiotic and says, like most doctors will, be sure that your son completes the full 10-day course. She smiles warmly and begins to usher you out of her office. It’s late in the day and the waiting room is full of sick kids and anxious parents.
This is your son. You’ve done your homework and you know the issues.
What do you do?