Side Effects of Sulfonamides

Sulfonamides are a class of antibiotics. They were the first effective antibiotics, discovered in 1935. Sulfonamides are bacteriostatic because they prevent the growth of bacteria and give the body's immune system a chance to fight off bacteria. They are used to treat conditions like urinary tract infections and pneumonia. Examples of sulfonamides are sulfisoxazole, sulfadiazine, sulfamethoxazole and sulfasalazine. If you are taking sulfonamides you should be aware of potential side effects.

• Sulfonamide Side Effects

Side Effects

• Side effects of sulfonamides such as sulfasalazine are diarrhea, dizziness, headache, loss of appetite, sensitivity to sunlight, nausea, vomiting and tiredness.

Hematologic Side Effects

• When sulfonamides are taken for a long time, they may lead to blood side effects. It is important to see your doctor regularly to monitor your blood status. Sulfonamide side effects on blood are low white blood cell count, low red blood cell count, low platelet counts, agranulocytosis, aplastic anemia, eosinophilia and prothrombinemia.

Allergic Side Effects

• If you are allergic to penicillin or cephalosporins, it is possible that you may be allergic to sulfonamides. Allergic reactions to sulfonamides include skin rash, itching, hives, swelling, sore throat, fever, joint or muscle ache, pale or yellow skin, difficulty swallowing, tiredness, unusual bleeding or bruising and weakness. If you notice any of these signs, call your doctor immediately.

Adverse Side Effects

• Sulfonamides also can have more serious side effects. These include severe stomach cramps and pain, stomach tenderness, blood in urine, severe diarrhea which may also be bloody, increase or decrease in the amount of urine, increase or decrease in how often you urinate, increased thirst, lower back pain, mood or mental changes, pain or burning while urinating and swelling of the front part of the neck.

Precautions

• If you are allergic to any medications, tell your doctor before you take a sulfonamide drug. Certain drugs interact with sulfonamides and patients are advised to avoid them if they are taking a sulfonamide medication. These drugs are: bepridil, cisapride, dofetilide, levomethadyl, mesoridazine, pimozide, terfenadine and thioridazine.

Helpful Information

• Dizziness is a side effect of sulfonamides. If taking a sulfonamide, you should not do anything that requires being alert, such as driving, until you know how this medication affects you. Cover your skin and wear a hat when you are out in the sun to prevent effects of sensitivity to sunlight.