Medically reviewed by Drugs.com. Last updated on Feb 22, 2023.
Uses for RE-Azo
Phenazopyridine is used to relieve the pain, burning, and discomfort caused by infection or irritation of the urinary tract. It is not an antibiotic and will not cure the infection itself.
In the U.S., phenazopyridine is available only with your doctor's prescription.
Before using RE-Azo
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Although there is no specific information comparing use of phenazopyridine in children with use in other age groups, it is not expected to cause different side effects or problems in children than it does in adults.
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of phenazopyridine in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with Medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Interactions with Food/Tobacco/Alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency or
- Hepatitis or
- Kidney disease—The chance of side effects may be increased.
Proper use of RE-Azo
This medicine is best taken with food or after eating a meal or a snack to lessen stomach upset.
Do not use any leftover medicine for future urinary tract problems without first checking with your doctor. An infection may require additional medicine.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For relieving pain, burning, and discomfort in the urinary tract:
- Adults and teenagers—200 milligrams (mg) three times a day.
- Children—The dose is based on body weight and must be determined by your doctor. The usual dose is 4 mg per kilogram (kg) (about 1.8 mg per pound) of body weight three times a day.
- For relieving pain, burning, and discomfort in the urinary tract:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using RE-Azo
Check with your doctor 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 medicine .
Phenazopyridine causes the urine to turn reddish orange . This is to be expected while you are using it. This effect is harmless and will go away after you stop taking the medicine. Also, the medicine may stain clothing.
For patients who wear soft contact lenses:
- It is best not to wear soft contact lenses while being treated with this medicine. Phenazopyridine may cause discoloration or staining of contact lenses. It may not be possible to remove the stain.
For diabetic patients:
- This medicine may cause false test results with urine sugar tests and urine ketone tests. If you have any questions about this, check with your health care professional, especially if your diabetes is not well controlled.
Before you have any medical tests, tell the person in charge that you are taking this medicine. The results of some tests may be affected by this medicine.
Side Effects of RE-Azo
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- Blue or blue-purple color of skin
- fever and confusion
- shortness of breath, tightness in chest, wheezing, or troubled breathing
- skin rash
- sudden decrease in the amount of urine
- swelling of face, fingers, feet, and/or lower legs
- unusual tiredness or weakness
- weight gain
- yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common or rare
- itching of the skin
- stomach cramps or pain
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
More about Re-Azo (phenazopyridine)
- Check interactions
- Compare alternatives
- Side effects
- Dosage information
- During pregnancy
- Drug class: miscellaneous genitourinary tract agents
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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.