Overuse of antibiotics leads to drug resistance
DEAR DOCTOR: Do you, or do you not, need to take a whole course of antibiotics even when you begin to feel better? I’ve always dutifully done so, but new reports seem to suggest otherwise.
DEAR READER: Antibiotics have undoubtedly saved countless lives. But we now live in a world in which some bacteria no longer succumb to the common drugs used against them, and we fear that the overuse of antibiotics may lead to further resistance.
The “take all your antibiotics” advice stems from a long-held worry that bacteria not killed by the antibiotic could develop resistance to that antibiotic. The problem is, bacteria are not one-size-fitsall. Some bacteria, such as those that cause tuberculosis, gonorrhea, salmonella and malaria, can quickly become resistant to antibiotics, so it is important to kill them completely.
Other bacteria are slower to develop resistance, so to have some lingering bacteria is less problematic. What is more worrisome about long regimens of antibiotics is that they also affect other bacteria that reside normally in our bodies, not causing infections. Not only do the “good” bacteria suffer,
some of the “bad” bacteria can become resistant to that antibiotic and later cause infections that cannot be killed by the prior drug.
Complicating matters is the nature of various antibiotics themselves. The antibiotic azithromycin, for example, has a half-life of three days, meaning that although a typical course is only five days, the drug stays in your system for many days after you finish.
We obviously need more studies on the duration of antibiotic regimens, but the major cause of the antibiotic-resistance problem is the overprescribing of antibiotics. The federal Centers for Disease Control and Prevention has estimated that 30 percent of all antibiotic prescriptions are unnecessary. Most of this overprescribing is for upper respiratory symptoms.
We should focus less on the duration of the antibiotic regimen and more on whether the antibiotic is necessary. If patients and medical practitioners use antibiotics judiciously, we may be able to curb the rising rate of antibiotic resistance.
Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.