Phenazopyridine Risks, Warnings, and Complications

Precautions Before Starting Phenazopyridine

Tell your doctor if you have ever had an allergic reaction to phenazopyridine, any ingredients in phenazopyridine tablets or capsules, or any other medicines. Your pharmacy can give you a list of ingredients.

Give your healthcare provider a complete medical history. Phenazopyridine may not be right for people with certain medical conditions such as liver disease, kidney disease, or phosphate dehydrogenase G6PD deficiency (a genetic enzyme deficiency).

Give your doctor a complete list of all your medications, including prescription drugs, OTC medicines, vitamins, dietary supplements, and herbal products. This can help avoid serious drug interactions.

Tell your doctor if you are pregnant, could be pregnant, plan to get pregnant, or are breastfeeding. Phenazopyridine may pass through breast milk to a nursing baby - the safety of this medication in infants has not been established. 

This medication may not be safe for the geriatric population. If you are over the age of 65, talk to your doctor about the potential benefits versus risks of taking phenazopyridine.

Precautions During Use of Phenazopyridine

Keep all your medical and lab appointments while on phenazopyridine. Your doctor may want to order certain laboratory and urine tests to check if your infection has cleared. 

Tell laboratory personnel that you are on phenazopyridine before you have any tests. Phenazopyridine can interfere with the results of lab tests, including urine tests for glucose and ketones. People with diabetes should use Clinitest and not Clinistix or Tes-Tape to check their urine for sugar. Urine checks for ketones (Acetest and Ketostix) may give false test results. 

Phenazopyridine can stain your teeth, clothing, and soft contact lenses. Do not crush or chew the tablets to protect your teeth. Avoid wearing soft contact lenses while taking phenazopyridine.

Do not take anyone else’s prescription phenazopyridine or share your medication with others. Your prescription of phenazopyridine will likely not be refillable.

If you use something like AZOTest Strips to detect UTI and are taking OTC phenazopyridine, keep an eye on your symptoms. Call your doctor if the pain persists or if you still have urinary irritation after 2 days.

Contact your doctor if you become pregnant while taking this medicine.

Phenazopyridine Drug Interactions

Phenazopyridine does not have any known possible drug interactions with other medications. However, you should give your healthcare professionals a complete list of your medications, including prescription drugs, over-the-counter medicines, vitamins, dietary supplements, and herbal products. Also, tell your health care provider if you smoke, drink alcohol, or use illegal drugs because some of these substances can cause serious health complications when used with prescription and OTC drugs.