Hello Mrs., Several antibiotics are compatible with breastfeeding, don't worry. The important thing here is to treat yourself properly. To do this, it is important to avoid using an antibiotic that has been taken in the last 3 months. I strongly recommend that you tell your doctor and pharmacist the medications that have been used recently, in addition to making sure to do a urine analysis (culture) to determine the bacteria that is causing this problem. Once the bacteria is identified, we will know which antibiotic could be used. Taking into account your breastfeeding and the antibiotics taken recently, we will select the best choice for you.