An emerging strain of extremely drug-resistant tuberculosis (XDR-TB) highlights the reason why you should finish the course of antibiotics prescribed by your doctor for an infection.
MOSCOW -- A virulent strain of tuberculosis resistant to most available drugs is surfacing around the globe, raising fears of a pandemic that could devastate efforts to contain TB and prove deadly to people with immune-deficiency diseases such as HIV-AIDS.
Known formally as extensively drug-resistant TB, or XDR-TB, the strain has been detected in 37 countries. It arises when the bacterium that causes TB mutates because antibiotics used to combat it are carelessly administered by poorly trained doctors or patients don't take their full course of medication. Rather than being killed by the drugs, the microbe builds up resistance to them.
At least 50 percent of those who contract this strain of TB will die of it, according to medical experts. In trying to stop the spread of the disease, which can be transmitted through coughing, spitting or even speaking, health officials have imposed sometimes extreme controls on infected people.
(I've written about those extreme controls before and wondered if similar measures could stop the spread of AIDS.)
It seems that more research needs to be done to determine how long is long enough, because there are risks associated with taking antibiotics for too long as well as for too short a time.
In another one of those "and why hasn't THIS been done before?" kind of studies, Rachida el Moussaoui and colleagues at the Amsterdam's Academic Medical Center, randomized 119 patients to receive either 3 days or 8 days of amoxicillin for bacterial pneumonia. Though the 8-day course has long been the universal standard, the 3-day course proved equally effective--and half as likely to produce adverse side effects such as antibiotic-associated diarrhea or drug allergy.
Of greater concern are the unseen side effects of those extra days of unnecessary antibiotics--especially the selective pressure they place on the body's trillions of resident bacteria. The longer the course of antibiotic, the higher the level of drug resistance bred into our native bacteria. Thanks to the wonders of bacterial gene swapping, this drugs resistance can easily end up in truly dangerous bug such as the strep, staph, and haemophilus behind most cases of bacterial pneumonia. ...
Still, the study's conclusion contains a powerful if painfully obvious message. There's no scientific basis for the duration of antibiotic therapy for many common infections. With respiratory infections such as pneumonia accounting for an estimated 75 percent of all antibiotic prescriptions, determining the shortest EFFECTIVE course of antibiotics for these ills could go far in reducing drug resistance in all of us.
Till then, of course ... be sure to take your antibiotics as prescribed, lest a too-short course fail to cure you.
More research please, and us laymen should continue to trust our doctors.