Pyridium - National Multiple Sclerosis Society

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About this Medication
  • Brand Name: Pyridium (U.S. and Canada)
  • Chemical Name: phenazopyridine (fen-az-oh-peer-i-deen)
  • Usage in MS: Urinary Tract Infections
  • Generic Available: Yes


Phenazopyridine is used to relieve the pain, burning, and discomfort caused by urinary tract infections. It is not an antibiotic and will not cure the infection itself. This medication is available in the U.S. only with a prescription; it is available in Canada without a prescription. The medication comes in tablet form.


The medication causes the urine to turn reddish orange. This effect is harmless and goes away after you stop taking phenazopyridine.

It is best not to wear soft contact lenses while taking this medication; phenazopyridine may cause permanent discoloration or staining of soft lenses.

Check with your physician if symptoms such as bloody urine, difficult or painful urination, frequent urge to urinate, or sudden decrease in the amount of urine appear or become worse while you are taking this medication.

Phenazopyridine has not been studied in pregnant women. It has not been shown to cause birth defects in animal studies.

It is not known whether this medication passes into breast milk. It has not been reported to cause problems in nursing babies.

Possible Side Effects

Uncommon side effects that typically go away as your body adjusts to the medication and do not require medical attention unless they continue or are bothersome: dizziness; headache; indigestion; stomach cramps or pain.

Unusual side effects that should be reported to your physician: blue or blue-purple color of skin; fever and confusion; shortness of breath; skin rash; sudden decrease in amount of urine; swelling of face, fingers, feet and/or lower legs; unusual weakness or tiredness*; weight gain; yellow eyes or skin.

*Since it may be difficult to distinguish between certain common symptoms of MS and some side effects of phenazopyridine, be sure to consult your health care professional if an abrupt change of this type occurs.