How Long Should I Take My Antibiotics?
Last November, the World Health Organization (WHO) sponsored Antibiotic Awareness Week 20161. One of its goals was to make everyone aware of the problems associated with the misuse of antibiotics, which can lead to antibiotic resistance. With repeated exposure to antibiotics, bacteria have been able to mutate and develop defenses that neutralize an antibiotic’s effect on them. Moreover, these bacteria are able to share this evolved genetic information with other bacteria that have never had any contact with the drug, but still become resistant to it.
Antibiotics are commonly available directly to consumers, even without prescriptions, which is one the reasons for widespread overuse. Many countries (including most in Latin America) do not require prescriptions for their use. In the United States, antibiotics can easily be obtained without prescription on the internet or by crossing the border into Mexico. Many of the same antibiotics are also available, often with other names, in pet stores (available for fish infections, among other things). And they are found in many ethnic grocery stores/pharmacies throughout our country.
In describing the misuse of antibiotics, WHO cites overuse as the main cause, particularly the use of antibiotics when they are not really indicated. For instance, most upper respiratory infections, such as colds, are actually caused by viruses, which are not affected by antibiotics, but many antibiotics are taken for them in the United States and around the world without any scientific or medical rationale. This added exposure of antibiotics to the world’s bacteria increases resistance.
Of course, there are also infections that do require antibiotics; for example, bacterial infections of the ears, urinary tract, lungs, or Strep throat. In those cases, the WHO advice was as follows: “always complete the full prescription, even if you feel better, because stopping treatment early promotes the growth of drug-resistant bacteria.”
In July of this year, Dr. Martin J. Llewelyn and his colleagues took issue with the advice regarding completing the course of antibiotics. In their article in the British Medical Journal2, they state “the idea that stopping antibiotic treatment early encourages antibiotic resistance is not supported by evidence, while taking antibiotics for longer than necessary increases the risk of resistance. Fundamental to the concept of an antibiotic course is the notion that shorter treatment will be inferior. There is, however, little evidence that currently recommended durations are minimums, below which patients will be at increased risk of treatment failure.”
There is a danger here of interpreting their findings to support stopping antibiotics when patients simply feel better. Whereas, in some cases, correct durations of treatment have not been scientifically established, some others most definitely have been. Unfortunately, one of the examples cited in the Llewelyn article was a study that showed that a three-day course of penicillin was as effective as the currently recommended 10-day course to treat the symptoms of Strep throat. This flies in the face of some of the most definitive infectious disease research ever done. Dr. Rammelkamp and his colleagues showed clearly that, even though symptoms abate after a few days of treatment (and often without any treatment), preventing rheumatic fever that can follow streptococcal pharyngitis does not always occur without 9-10 days of continuous treatment.3
Taking any medicine only “until you feel better” should not be any more applicable to antibiotics than it is for your blood pressure medicine or any other medicine being used for a chronic disease process. Sound advice regarding the use of antibiotics and the length of the course is still being developed and will be informed only by continuing research in infectious diseases. As this occurs, it seems prudent to make those decisions in collaboration with your health care providers. They will always be in the best position to be updated on the latest legitimate research findings, and to advise you when antibiotics are indicated, and when to stop taking them.
3 CHARLES H. RAMMELKAMP, LEWIS W. WANNAMAKER, AND FLOYD W. DENNY, The Epidemiology and Prevention of Rheumatic Fever, Bulletin of the New York Academy of Medicine, vol. 28, no. 5, 1952, pp. 321-324.
W.T. Williams, Jr., MD
Internist and Pediatrician