"I used to stockpile antibiotics," admits Ann Pascual, an editor for an Internet-based company in northern California. "I'd get a prescription, take half of it, and keep the rest. Sometimes I'd give a handful to friends who were sick. Instructions on the label? I don't think I ever really even read them."
Fortunately, Pascual suffered no ill consequences from taking antibiotics haphazardly. Barbara Jamison wasn't so fortunate. A few years ago she stopped taking the antibiotic sulfamethoxazole plus trimethoprim after an infection cleared up, but before the prescription ran out. Two weeks later she started the pills again when the symptoms reappeared. "Suddenly I had this horrible allergic reaction," she remembers. "I was throwing up and I was so weak I could hardly stand. I really thought I was dying. I had to be rushed to an emergency clinic." A doctor later told her that she might have suffered a hazardous drug interaction.
Widespread misuse of prescription drugs
Pascual and Jamison aren't alone. Studies show that only one-third of medicine-takers follow the instructions on the label to the letter. Astonishingly, one in three Americans never take any of their prescribed medication at all, and close to 50 percent misunderstand how to take them when they do. Others may double up on medications, with the dangerous reasoning that if one pill may be good, two will be better. But the largest problem appears to be that most of us take only some of the drugs that we're prescribed.
Sometimes called "America's other drug problem," the misuse of medications like antibiotics has become a national epidemic, researchers say. "Only about half of patients with asthma or with high blood pressure take their medications as prescribed, even though both of these illnesses are potentially very serious," says Charles Ponte, a professor of clinical pharmacology and family medicine at West Virginia University. Equally worrisome are patients who stockpile and then share medications with friends or family. "People say, 'You've got a pain in your shoulder? Here, try one of these pills my doctor gave me.' There's a potential for real problems if that person happens to be taking some other medication that causes an adverse reaction," Ponte warns.
Among Consumer Health Interactive readers responding to an informal poll posted on our web sites, one in five reported that they failed to take antibiotics as directed. The majority -- 78 percent -- reported that they finished the entire course of antibiotics prescribed. But 14 percent said they took the antibiotics only until they felt better; four percent took a few and saved the rest for another time; and another three percent failed to fill the prescription.
And consumers may be less diligent about taking their medicine than they report. In an issue of the journal Sexually Transmitted Diseases, a study of women who were taking doxycycline for chlamydia reported that after treatment, almost every woman said she had taken the medicine as directed. However, a secret counter inside the medicine bottle cap told a different story: Only 16 percent of the patients took the medication exactly as prescribed.
More than 100,000 people die annually from problems related to prescription medications, recent surveys show, and experts attribute the crisis in part to people's failure to read or follow label instructions on medications. Ten percent of all hospital admissions are due to patients improperly taking their medications, at a cost to the nation of an estimated $15.2 billion a year. All told, the problem that doctors call "nonadherence" costs more than $100 billion, according to the National Pharmaceutical Council.
Doctors aren't much better than patients
Among the most widely prescribed drugs -- and the most misused -- are antibiotics. In one study of children prescribed a 10-day course of penicillin for streptococcal infections, 56 percent were no longer taking the drug after the third day. By the ninth day, 82 percent had stopped taking the pills.
Even doctors have trouble following doctors' orders, it turns out. Stanford University professor Terrence Blaschke and his colleagues asked a group of medical students to follow a two-week regimen of taking pills. The researchers used electronic pill containers to monitor how well the medical students followed instructions. Those who were told to take their pills twice a day did better than those instructed to pop pills three times a day. But none of them did well enough to inspire much confidence. "Only about 28 percent of the pills were taken as prescribed," says Blaschke, a professor of medicine at Stanford University.
Why are we so bad at following medication instructions? There are plenty of reasons. We're busy. We forget. In some cases we don't really believe in the drugs we've been prescribed, so we take them only halfheartedly. "People often stop taking antibiotics when the symptoms go away," says Ponte. "And then when another infection comes along, they open the medicine cabinet and grab the leftover pills, assuming that any old antibiotic will do."
Growing fears of antibiotic resistance
Ann Pascual sometimes took only half the prescribed dosage of antibiotics because she thought that if she took too many antibiotics they would cease to have an effect. The opposite is true, experts say. Taking only part of the prescription is what allows some germs to survive and go on to become resistant to antibiotics. Surprisingly, the worst danger comes not from stopping the medication once the infection goes away, but from taking only partial doses from the beginning. "What we really worry about is the person who takes only one pill a day instead of the two or three that are prescribed," says Blaschke. "Low concentrations of an antibiotic are the biggest danger when it comes to creating antibiotic resistance in bacteria."
And antibiotic resistance has become an increasingly dangerous problem, as so-called "superbugs" emerge that can withstand the assault of almost all available antibiotics.
In 1945, shortly after hospitals began using penicillin, scientists discovered resistant strains of Staphylococcus aureus, bacteria which cause pneumonia and toxic shock syndrome. Another drug called methicillin came out in 1960, but within one year there were strains resistant to that, too. Flouroquinolones (such as Ciprofloxacin), which were introduced in the 1980s, killed 95 percent of methicillin-resistant S. aureus. Within one year, however, 80 percent of those strains had become resistant to flouroquinolones as well.
Today, more than 95 percent of S. aureus strains are penicillin-resistant worldwide, and in some hospitals, more than half of all those strains are also resistant to methicillin. And a new form of staphylococcus has begun to appear that is invulnerable to virtually all forms of antibiotics. An October 2007 report in the Journal of the American Medical Association (JAMA) found that more than 90,000 Americans contract potentially life-threatening infections every year from methicillin-resistant Staphylococcus aureus, or MRSA. The study estimates suggest that drug-resistant staph may kill more than 18,000 people a year in the United States, which would exceed the number of annual deaths caused by AIDS. MRSA typically infects victims through an open skin wound, sometimes even through a small scratch. The study found that the overall incidence rate was 32 invasive infections per 100,000 people -- a figure that the JAMAs editors called astounding.
Some 90,000 patients die each year of hospital-acquired infections in United States -- a number that could double if staph infections become untreatable. Surgical procedures that grew commonplace after the development of antibiotics could become increasingly treacherous again. Perhaps worst of all, we could find ourselves helpless against certain bacterial strains -- and as in the dark ages before penicillin, a simple kitchen cut or scraped knee thus infected could prove fatal.
How careful do you need to be?
Stopping a drug before the prescription runs out poses another serious danger, too: the risk that an infection will come roaring back.
Fortunately, there is some room for error when it comes to taking antibiotics. In general, bacteria-fighting medications like penicillin and tetracycline are "forgiving" drugs, says Blaschke -- that is, you can skip a dose now and then and not compromise their effectiveness. Exactly how forgiving a drug is, however, depends in part on the seriousness of the infection and the strength of your own defenses.
"For someone with HIV infection, taking drugs exactly as they're prescribed is critical," says Ponte. "But if you've been prescribed an antibiotic for a respiratory infection, you can miss a dose or two and not worry."
Even so, pharmacologists say, it's important to follow the instructions on the label. "At long last," Ponte notes, "we've got very good drugs to control things like high blood pressure and high cholesterol. We've got medications that can help protect people with asthma or diabetes. But the only way to get the full benefit from those drugs is by taking them as directed.
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