What You Should Know About Azo Pills

Get the facts on Azo pills, including how they work, who should and shouldn't take them and a few side effects to be aware of before you use the product.

If you've ever had a urinary tract infection (UTI), you've probably heard about Azo pills. This medication is meant to help alleviate the discomfort you experience in your urinary tract or bladder region from a UTI, as well as pain brought on by surgery or the use of a catheter.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

But Azo pills aren't for everyone. Read on to learn whether an allergy or medical condition might exclude you from this particular treatment.

All About Azo

Azo is the brand name for phenazopyridine hydrochloride, though this medication is also available under other names, including Uristat and Pyridium. Azo acts as an analgesic (pain reliever) within the urinary tract, so it is commonly recommended for those with discomfort due to a UTI or recent catheter use.

The active ingredient is processed quickly by the kidneys and is then expelled into the urine. In the urinary tract, Azo provides pain relief by soothing the mucous lining, although the exact mechanism is not yet known.

According to the Mayo Clinic, Azo is typically a prescribed medication, though it can be obtained over the counter. However, it does not fight infection — it's not an antibiotic — but rather eases the symptoms of infection or other types of urinary irritation.


Azo cannot cure a UTI or any other infection. If you believe you have an infection, you should see your doctor, who can prescribe an antibiotic or other proper treatment.

How Azo Is Used

Azo Standard is available as 95-milligram pills, and the proper dose is usually two pills up to three times a day, per the U.S. National Library of Medicine. A maximum-strength version is also available, which offers 97.5-milligram pills.

Doctors often recommend taking Azo for the first two days of antibiotic treatment to ease the pain and burning of urination while the antibiotic takes effect. However, you should read the package instructions carefully, and keep in mind that most doctors caution against taking Azo for more than two days, as it can mask the presence of a more serious problem.

Who Should Take Azo Pills

If you have allergies to food, dyes or any kind of preservatives, let your doctor know before you take Azo pills. And if you have hepatitis or kidney disease, taking Azo may be contraindicated.

For those who may be pregnant or breastfeeding, know that Azo has received a class B rating, which means that animal studies haven't been shown to harm to the fetus, but there are no similar studies in pregnant women.

According to the compendium Drugs for Pregnant and Lactating Women, there aren't any adequate reports or well-controlled studies in human fetuses using this drug, and while one study did show that phenazopyridine crosses the human placenta, more research is needed. Rodent research showed Azo usage to be safe, even at higher-than-normal dosage levels. The same resource notes that Azo pills are likely compatible with breastfeeding.

If you're a diabetic, keep in mind that this medicine may wreak havoc with your urine sugar tests or urine ketone tests. Check with your doctor before taking Azo pills, especially if your diabetes isn't well-controlled.

Not sure whether Azo is for you? If you're older, taking a cranberry capsule might be the ticket to beating a UTI, especially if you're at high risk. A 2014 study in the Journal of the American Geriatrics Society found that after taking cranberry capsules twice a day, older people with high UTI risk saw their UTI incidence drop.

Azo's Side Effects

Side effects of Azo are rare, but they could include headache, dizziness and stomach pain.

And while Azo can help relieve urinary tract pain, it also has one other effect you're sure to notice: It causes a change in the color of urine (look for a reddish-orange hue). The active component in Azo is a dye, which causes this color change. Luckily, this effect is harmless and ends soon after you stop taking the medication.

A word of caution for those who wear soft contact lenses: Remove them when you're taking Azo pills and don your glasses instead. The same dye that changes your urine color can also stain lenses if they come in contact with the pills, or with your hands after you've handled the pills, and the affect may be permanent, according to Azo's website.

Azo dye can also leak somewhat between eliminations, so many users wear panty liners or dark-colored underpants while taking the medication.

Because of this color change, doctors are usually unable to do an in-office urinalysis (the typical urine test for a UTI involves assessing the color of urine, which cannot be done when Azo changes its color). For this reason, it might be a good idea to hold off on taking Azo when you initially experience urinary discomfort, until a doctor can conduct a diagnostic test. If Azo does make an in-office test impossible, a doctor can send the urine sample off for a culture to determine if E. coli or another bacterial culprit is present.