The majority of people who use fluorouracil experience few, if any, negative side effects, although any new symptoms that develop after beginning treatment with this medication should be reported to a doctor for further medical evaluation. Some of the most frequently reported fluorouracil side effects include skin irritation, hair loss, or visual disturbances. More serious side effects of this medication that should be reported to a doctor right away include severe gastrointestinal disturbances, blood in the urine, or allergic reactions. Any specific questions or concerns about potential fluorouracil side effects in an individual situation should be discussed with a doctor or other medical professional.
Minor skin irritation is among the most common fluorouracil side effects. There may be a temporary burning or stinging sensation at the application site or at the location of the injection, depending on the method of administration. Dry skin and pigment changes may also occur, although these side effects usually disappear after the medication has been discontinued. Significant pain, swelling, or blistering of the skin may indicate the development of complications and should be reported to a doctor.
Temporary hair loss may occur when using this drug, but this is almost always reversible when the medication is no longer needed. Visual disturbances such as blurred vision or itchy, watery eyes may develop while this medication is being used. If these symptoms become bothersome, additional medications or other treatment methods may be prescribed to combat the unwanted side effects. Occasionally, the dosage may need to be adjusted or the doctor may prescribe a different drug in its place.
Mild to moderate nausea, vomiting, or diarrhea are relatively common fluorouracil side effects. If these symptoms become severe or are accompanied by a fever, a doctor should be consulted right away. Sudden or severe abdominal pain should be reported to a medical professional as well. Black or bloody stool or vomit that resembles coffee grounds could indicate the development of severe complications and should be treated as a medical emergency.
Allergic reactions are possible fluorouracil side effects, although these reactions are usually mild. Slight redness, itching, or swelling do not usually indicate a serious condition, although pain or blistering of the skin should be evaluated by a physician. A potentially life-threatening type of allergic reaction known as anaphylaxis should be treated as a medical emergency, as death may occur within a matter of minutes. Anaphylactic symptoms may include chest pain, facial swelling, and difficulty breathing.