Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.
You may get infections more easily, even serious or fatal infections. Call your doctor right away if you have signs of infection such as:
fever, chills, sore throat;
mouth sores, red or swollen gums;
pale skin, easy bruising, unusual bleeding; or
chest discomfort, wheezing, dry cough or hack, rapid weight loss.
Also call your doctor at once if you have:
fever with headache, rash, and vomiting;
a skin rash, no matter how mild;
severe nausea or vomiting when you first start taking sulfasalazine;
little or no urination, urine that looks foamy;
puffy eyes, swelling in your ankles or feet, weight gain; or
liver problems--loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes).
Common side effects may include:
nausea, vomiting, upset stomach, loss of appetite;
headache;
rash; or
low sperm count in men.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Sulfasalazine side effects (more detail)
