Take care with antibiotics

November 08, 2012 By Lynne Todd, M.D.

Winter is cold and flu season, and if you're suffering from one of these common illnesses, it's tempting to ask your doctor to prescribe an antibiotic.

But for some illnesses an antibiotic may not do any good. The common cold, flu, most cases of bronchitis and many simple, acute sinus infections are caused by viruses, so antibiotics don't work against them. Antibiotics are effective only against bacterial infections, like strep throat, severe or prolonged sinus infections, ear infections and others.

There are many different antibiotics used to treat a wide variety of infections. Some antibiotics, like penicillin, kill bacteria. Others, like tetracycline, slow their growth. Each antibiotic works on a different aspect of the bacteria's functioning. Some antibiotics cause damage to the bacteria's cell walls; others prevent nutrients from reaching the bacteria.

So what's the harm in taking antibiotics, even if you're not sure you need them? Why not throw everything we have at the infection that's making us miserable?

Antibiotics can have side effects, including mild nausea, diarrhea and stomach pain. There's also a risk of potentially dangerous allergic reactions. Because antibiotics also kill “helpful” bacteria in our bodies, their use can lead to other conditions. For example, helpful bacteria in the vagina help control overgrowth of candida yeast; killing these bacteria can lead to a candida overgrowth (yeast infection). Antibiotics that kill the normal bacteria in your intestine can allow overgrowth of C. difficile bacteria, which can lead to an infection that causes diarrhea and other symptoms.

Additionally, antibiotic use can lead to problems down the road, because the more you take them, the more likely bacteria will develop a resistance to the drugs. This happens because antibiotics might kill some, but not all, bacteria. Those left may mutate to build up a resistance.

Antibiotic-resistant bacteria can not only make you sick – they can spread to others, causing a wider, public problem. MRSA (methicillin-resistant Staphylococcus aureus) is an example. MRSA bacteria are resistant to methicillin and certain other antibiotics commonly used to treat staph infections. In otherwise healthy people, MRSA causes a skin infection, but in those with weakened immune systems it can lead to bloodstream infections, surgical-site infections or pneumonia. While MRSA infection rates have been declining in healthcare settings, rates have been steadily rising in healthy people, causing concern among health officials.

Other antibiotics may also be losing their effectiveness as bacteria develop resistance to these medications. If you think you have a bacterial infection, talk to your doctor, who will know the best—and safest – way to help you beat it.

Lynne Todd, M.D. is a member of The Hospital of Central Connecticut (HOCC) medical staff, practicing with Doctors of Central Connecticut, www.doccs.com.