Sulfadiazine is an antibiotic medicine, also called a sulfonamide antibiotic. It is classified as a sulfa drug. Doctors prescribe it to treat bacterial infections, such as urinary tract infections. Sulfadiazine inhibits the growth and spread of bacteria, though it will not work for viral infections, such as colds or the flu.

This medicine is taken orally in the form of a tablet. Patients should drink a full glass of water when taking a dose. In addition, consuming extra water during the day may help prevent some side effects. This drug should be taken without food as well.

Sulfadiazine is typically taken three to six times daily. Patients should space the dosage in even intervals recommended by their physicians. They should take each dose at the same times each day to maintain constant levels of the antibiotic in their bodies. Even if one feels better and the infection subsides, one must finish the full course of medication.

Patients may experience some side effects. Fatigue, mild dizziness, and headaches may occur. Patients also may notice an increased sensitivity to sunlight. Sunscreen and protective clothing are usually recommended. They may also experience nausea, vomiting, and diarrhea as well as a loss of appetite.

Sulfadiazine may cause more serious side effects that require emergency medical help. Signs of a possible allergic reaction may include difficulty breathing, closing of the throat, and facial swelling. It can also cause fainting and hives.

Other severe side effects can include bloody, painful, or difficult urination as well as abdominal cramps and watery diarrhea. Some patients may notice a ringing in the ears; unusual fatigue; and jaundice, which is a yellowing of the skin and eyes. Chills, sore throat, and unusual bruising may also occur.

Not all patients are good candidates for this antibiotic medicine. People who have had kidney disease, liver disease, or asthma may be unable to use it. Blood problems, such as aplastic anemia as well as enzyme problems may preclude a person from taking it as well.

Women who are pregnant or breastfeeding should not use this sulfa drug without a doctor's approval. It is unknown whether sulfadiazine can cause birth defects or harm to a nursing infant. In addition, it should never be administered to children who are younger than two years old.

Before taking sulfadiazine, patients should disclose all other supplements and medicines they are taking. It may interact with drugs such as phenytoin, warfarin, and oral diabetes medications. Cyclosporine, methotrexate, and tolbutamide may also interact with sulfadiazine.