Nitrofon 100mg Tablet is an antibiotic used to treat and prevent urinary tract bacterial infections. It should be taken as prescribed by a doctor, with food to avoid nausea. It is best taken daily and continued for as long as prescribed. Side effects like nausea, vomiting, and diarrhea are temporary and go away during treatment. It may turn urine dark yellow or brown. Before treatment, inform your doctor if you are pregnant, breastfeeding, have liver, kidney, or heart problems, or are allergic to antibiotics.