Antibiotic resistance growing problem in fighting infections

By Dr. Adrew Smith: “Hey, Dr. Smith, can you give me a really strong antibiotic this time. Even if it's a brand name, I'll pay for it — I've just got to clear this sinus infection.”

Over the 20 or so years that I've practiced medicine, I've heard statements like that with increasing frequency. Why? Because the bacteria we treat have gotten increasingly resistant to the antibiotics we have, even the high-priced brand names. So where 20 years ago plain-old Amoxicillin or its beefed up cousin, Augmentin, or the famous Z-Pak (Azithromycin) or even an old sulfa med like Bactrim would clear up a sinus infection reliably, now these have a substantial failure rate, and even “big guns” like Levaquin are no guarantee of quick success.

Antibiotics and similar drugs, together called antimicrobial agents, have been around for some 70 years. When they first came out, they were almost miraculous in their healing powers, and they greatly reduced illness and death from infectious diseases. However, these drugs have been used so widely and for so long that the infectious organisms they treat have developed resistance to them. It works this way: Say an antibiotic kills off 99.9 percent of a certain bacteria infecting a person. But the 1/10th of a percent that are left survive because they have some mutation that makes them resistant to the antibiotic. This resistant bacterial population then multiplies, and that antibiotic will not work against them.

Worldwide this is a huge problem. Not only are there garden-variety infections like sinusitis that are resistant, but types of pneumonia, sexually transmitted diseases, tuberculosis, malaria, bowel, urinary and skin infections are also showing resistance. In fact there are some “super bugs” that are resistant to every antibiotic that has been tried against them. Last year, a report from the American Academy of Microbiology called antibiotic resistance “an international pandemic.” Up to 10 percent of all hospital patients develop a drug-resistant infection, increasing annual U.S. health-care costs by about $5 billion, according to the NIH. Worse yet, about 90,000 patients infected with drug-resistant bacteria die each year in the U.S. as a result of their infection, up sharply from 13,300 patient deaths in 1992. And worldwide, bacterial and parasitic diseases are the second-leading cause of death.

You may have read about methicillin-resistant Staphylococcus aureus (MRSA) — a potentially dangerous type of staph bacteria that is resistant to certain antibiotics and may cause skin and other infections. It used to be a relatively uncommon, hospital-acquired infection. Now we see it in our office practice on a regular basis, and only a couple of oral antibiotics are effective against it.

What's caused all this antibiotic resistance? A number of factors have contributed:

— The relatively few new types of antibiotics coming out each decade.
— The overuse of antibiotics to treat colds, viruses and other infections which don't need or respond to antibiotics.
— Partial treatment of infections which do not eradicate the bacteria.
— Heavy use of antibiotics in animal populations in the farming industry.
— Long courses of preventive antibiotics for certain conditions.

So, what can be done? Antibiotics need to be used selectively, for infections that are truly bacterial. When they are used, they should be used at their full dose and for long enough to knock out the infection. New antibiotics will be needed which bypass the current resistance of microbes. In addition, vaccination against some of the more common microbes is a very effective way to prevent ever getting some of these resistant infections.

However, there is one approach that doesn't work, but which I hear a lot. A patient may say, “I'm holding off on antibiotics so that when I need one it will really work.” Unfortunately, the resistance of the bacteria is based on the community resistance patterns. So when we catch a bacteria, it may be highly resistant to antibiotics even if we haven't taken an antibiotic for a long time. Likewise, if an antibiotic doesn't clear an infection, it isn't that, “that antibiotic just doesn't work for me,” but rather that the bacteria with which you are infected is resistant to that antibiotic. The next infection it might work fine.

At any rate, I sometimes grow a little nostalgic for the days when infections cleared more quickly and predictably, and we had a full armory of effective weapons at our disposal. But this is where we are, so careful and specific antibiotic use (and avoidance when appropriate) are more vital than ever. When treating infections, whenever possible we need a well-aimed bullet, not a shotgun.

Andrew Smith, MD is board-certified in Family Medicine and practices at 1503 East Lamar Alexander Parkway, Maryville. Contact him at 982-0835.