Phenazopyridine (Azo) for Urinary Infections: Usage and Side Effects

Neha Mittal   by Neha Mittal, MS, Biotechnology    Last updated on April 22, 2021,

phenazopyridine (Azo)

What is Azo UTI?

Azo is a medicine that is used to relieve symptoms of urinary tract infection (UTI) such as irritation in the urinary tract, pain, burning, and the feeling to urinate frequently. The generic name for this medicine is phenazopyridine. Azo is the brand name for phenazopyridine hydrochloride.

It is also available under other names such as Uristat and Pyridium. Azo acts as an analgesic or painkiller within the urinary tract and soothes the urinary tract. It is commonly recommended for individuals with urinary pain such as from a urinary tract infection (UTI) etc.

Do Azo pills cure UTI? Is azo good for a urinary tract infection?

The drug does not treat the cause of the symptoms. It can only help relieve them while you take other treatments that take some time to work.

See also: Causes of Urinary Tract Infection (UTI)

See also: Diagnosis and Tests for Urinary Tract Infection

How do Azo pills work?

Azo (Phenazopyridine) is a dye that acts as a painkiller. The active ingredient in this drug are quickly processed by the kidneys and then expelled with the urine.

If you are suffering with UTI, it can help provide relief in pain by soothing the lining of the urinary tract. However, the exact mechanism of Azo is not yet known.

Azo does not fight the infection and therefore cannot treat the cause of urinary tract irritation and pain, but it can help ease the symptoms of infection or other types of urinary irritation. It is useful for urinary discomfort due to an infection, but will not cure the infection.

How is Azo taken? How often do you take AZO for UTI?

A standard Azo version is available as 95 mg pill. Higher-strength (maximum-strength) version is also available as 97.5 mg pill. The dose constitutes two pills up to three times a day. Azo dosage is based on your medical condition and response to the medication.

Prescription phenazopyridine is available in 200 mg pills, and it is generally taken one pill at a time. Doctors often recommend that a patient take Azo for the first two days of antibiotic treatment to relieve the pain and irritation while the antibiotic takes its effect to cure the actual cause that is urinary tract infection or any other infection. Doctors caution against taking Azo for more than two days as it can cause more serious problems.

See also: Treatment of Urinary Tract Infection (UTI)

How to use Azo tablets?

You can take this medication by mouth, usually 3 times daily after meals or as directed by the doctor. If you are taking this medication along with antibiotics for urinary tract infection, it is cautioned not to take it for more than 2 days without talking to your doctor.

Azo urinary pain relief: What conditions does Azo treat?

Side effects of Azo

You can experience the following side effects as a result of taking Azo for UTI or for any other medical condition:

  • Headache
  • Dizziness
  • Stomach problems

Most people using this drug do not experience serious side effects. But some people may have serious problems such as:

  • dark urine
  • fever or chills
  • bruising/bleeding
  • weakness
  • shortness of breath
  • fast heartbeat
  • seizures
  • kidney problems
  • change in the amount of urine
  • bloody urine (hematuria)
  • stomach/abdominal pain
  • yellowing of skin
  • yellowing of eyes
  • vomiting or nausea
  • serious allergic reactions such as – rashes, itching, dizziness, breathing problems, swelling on face, throat or tongue

Tell your doctor immediately if you experience any of these serious side effects, though they occur rarely.

Azo UTI precautions: Precautions before taking Azo tablets

You should tell your doctor if you are allergic to the drug before taking it. This product may contain certain ingredients which can cause allergic reactions or other problems. You can talk to your doctor or pharmacist for more details.

Azo is not recommended in certain conditions such as:

Precautions you should take before taking Azo tablets:

  • Tell your doctor if you have a medical history of any of these diseases or medical conditions.
  • Do not drive nor do anything that needs alertness as the drug may make you dizzy. Do not consume alcoholic beverages when you are taking the medicines.
  • Azo can dye your urine and tears and change their colors. This may cause staining on the clothing and contact lenses. It is better to not wear contact lenses while you are taking this medication. This will become normal after you stop the medicine.
  • Tell your doctor if you are pregnant or plan to become pregnant before using the drug.
  • Tell your doctor if you are breastfeeding. However, it is not yet known whether the effect of this drug can be passed into the milk. But it is better to take necessary precautions and talk to the doctor before taking it.

Neha Mittal

Neha Mittal completed graduation in Biotechnology from Graphics Era University, Dehradun and Masters in Biotechnology from Amity University, Noida. In the past, she worked with Sharon Biomedicine Ltd., DUKES Products Ltd., and Forest Research Institute, Dehradun as researcher in biotechnology.


Neha loves singing and dancing in leisure time. She also enjoys traveling and maintains a collection of great novels.

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