FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

DOCTOR'S TREATMENT GAVE READER NEW MALADIES

Question: I've had a sore throat for at least six weeks. My doctor gave me an antibiotic but later discovered that my discomfort was caused by a fungal infection not a bacterial one. He said that what I had was called "thrush," and later decided that it was probably due to either taking the antibiotic and/or as an adverse reaction to an antidepressant I've been taking. I'm now taking a new medication for the thrush. I thought medicine was supposed to make me better, not make me sick. Does this type of problem happen very often?

Answer: First, I need to explain a bit about thrush. This is a yeast infection of the mouth that is common in those who have a depressed immune system specifically infants, diabetics, those who are on chemotherapy for cancer, and individuals with AIDS. It is quite uncommon in otherwise healthy individuals.

Thrush usually becomes apparent as easily identifiable mouth or throat sores. Patches of whitish "cottage cheese like" material are often present, and when these are removed, the tissue underneath is quite reddened and inflamed. Less commonly, the condition begins as a generalized sore mouth or throat without the classic "cottage cheese like" lesions.

I can't accurately tell you if it was the antibiotics or the antidepressant medications you have taken that are responsible for your thrush, although it is likely that both played a role in "setting the stage" for the illness. An antibiotic will inadvertently kill some of the normal bacteria that live in the mouth, along with killing the disease causing ones, and leave the mouth as a potential breeding ground for the thrush-causing yeast. There is now some evidence that certain antidepressants, particularly those like Prozac and Zoloft that doctors place in the category of "Selective Serotonin Re-uptake Inhibitors," can make a small number of people - about one percent - become more susceptible to thrush. We are not exactly sure why this is the case, though it may be because these medications cause some decrease in saliva production. Saliva is known to play a role in the body's immune defense against fungal throat infections.

It is possible that the combination of the undesirable effects of the medications you have taken has, just as your doctor told you, resulted in your new illness thrush.

You asked if this type of problem happens very often. My only partly tongue-in-cheek response: "You bet your sore throat it does!" Remember, medicine is not a perfect science. People vary greatly in the way they respond to various medications, and these differences are rarely predictable before the fact. Illness develops as a consequence of side effects from medical or surgical treatment with sufficient regularity that we've coined a word for this phenomenon "iatrogenic."

This word literally means, "physician induced," but you don't have to be a physician to be responsible for this kind of illness. Many people produce their own iatrogenic disorders with misuse of over-the-counter medications. That's one of the reasons these drugs have warning labels.

Prescription medications often have a much higher potential for producing an iatrogenic disorder. In fact, the potential for causing this type of side effect is one of the criterion used by the Food and Drug Administration in deciding whether or not a medication should be available only by prescription.

When you are taking a medication, whether it is a prescription or non-prescription product, be sure to report any new symptoms you develop to your doctor. Be aware that iatrogenic illness is not uncommon and that it can happen to you.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.