The biggest concern for potential users of the medication is the development of anemia if folic acid levels are reduced. This happens in a small percentage of patients, but should be considered if one of the following risk groups are present: malnutrition, pregnancy, geriatric, or alcoholic. The anemia is generally resolved once dosage of the antibiotic has ceased. Other side effects are usually minor and may include appetite loss, vomiting, stomach pains, nausea, or diarrhea. If these reactions are acute or chronic, they should be reported to a doctor as soon as possible.