Antibiotics are over-prescribed in the United States, Canada, and worldwide, often for infections that do not need their help, particularly respiratory conditions. While these unnecessary prescriptions may contribute to the development of resistant bacteria, there is another reason to be cautious about antibiotics: Direct harms caused by these drugs. Our group—a family physician, an infectious disease specialist, and a health sciences student—has published a review of the evidence about adverse effects of antibiotics commonly used in the community. Even though two of us are experienced physicians, and knew about many problems with drugs, we were surprised by the frequency and severity of some of these effects. Gut Reactions, Allergies, and Skin Rashes The review showed that for many antibiotics, over 10 percent of patients get gut reactions, such as stomach pain, discomfort, or diarrhea. This is particularly common in children given antibiotics for ear and throat infections. Every antibiotic causes allergic reactions in some people. A …