A urinary 'analgesic' dye that eases burning and urgency
Phenazopyridine
A urinary-soothing dye that eases the burning, stinging and urgency of a urinary infection, but does not treat the infection.
What is Phenazopyridine?
Phenazopyridine is a urinary 'analgesic' dye used to ease the burning, stinging and urgency that come with a urinary infection. It is important to understand that it only soothes the symptoms; it does not treat the infection itself, so it is used alongside an antibiotic, not instead of one. A well-known and harmless effect is that it turns the urine a bright orange or red colour, which can stain contact lenses, underwear and clothing. It is meant for short-term use only and is used with caution in people with kidney problems or the inherited condition G6PD deficiency.
Education and reference only. This is a plain-language guide to Phenazopyridine — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Phenazopyridine is an older medicine that acts as a soothing dye on the lining of the urinary tract. It is used to relieve the uncomfortable burning, stinging, urgency and frequent need to pass urine that often come with a urinary tract infection. The key thing to know is that it tackles the symptoms only and does nothing to clear the infection, so it is taken alongside an antibiotic rather than on its own. It is taken by mouth as a tablet for a short time, just while symptoms are at their worst.
How it works
Phenazopyridine passes out of the body in the urine, and as it does so it has a local soothing effect on the lining of the bladder and urinary passages, which dulls the burning, stinging and urgent feeling. Because it works directly on the urinary lining rather than on bacteria, it does not kill the bug causing the infection. That is why it is used only to make the person more comfortable while a proper antibiotic clears the infection, and why it is taken for just a short time until symptoms ease.
Company & origin
Originated / developed by: Generic (long-established).
An older urinary-soothing medicine used to ease the burning and urgency of a urinary infection while the infection itself is treated.
Practical use
How to take Phenazopyridine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth with or after food to reduce stomach upset, exactly as prescribed.
- Use it alongside, not instead of, the antibiotic for your infection, as it does not treat the infection itself.
- Use it only for a short time, usually a day or two until the burning and urgency settle, and stop when advised.
- Expect your urine to turn bright orange or red, and avoid wearing contact lenses, which it can permanently stain.
- Tell your prescriber if you have kidney problems or G6PD deficiency, as it may not be suitable.
Weighing it up
Advantages & disadvantages of Phenazopyridine
Advantages
- Quickly eases the burning, stinging and urgency of a urinary infection while the antibiotic works.
- Taken by mouth as a simple short course.
- A long-established medicine with decades of experience behind its use for symptom relief.
Disadvantages
- Only relieves symptoms and does not treat the infection, so an antibiotic is still needed.
- Turns the urine bright orange or red, which can permanently stain contact lenses and mark clothing.
- Must be used only for a short time, and used with caution in kidney problems and G6PD deficiency.
Practical use
Good to know
The single most important point is that phenazopyridine only relieves symptoms; it does not treat the infection, so it must not be used as a substitute for the antibiotic your prescriber gives you. It very commonly turns the urine bright orange or red, which is harmless, but it can permanently stain contact lenses and can mark underwear and clothing, so soft contact lenses are best avoided while taking it. It is intended for short-term use only, usually just a couple of days while symptoms settle; using it for longer is not appropriate. It is used with caution, or avoided, in people with kidney problems, because it can build up, and in people with the inherited condition G6PD deficiency, where it can cause red blood cells to break down. Rarely it can affect the blood or liver, so any yellowing of the skin or eyes, or feeling very unwell, should be reported.
Who should not take it / use with caution
- People who have had a serious allergic reaction to phenazopyridine should not take it.
- It is avoided or used with great caution in people with significant kidney problems, as it can build up.
- It is avoided in people with the inherited condition G6PD deficiency, because of a risk of red-blood-cell breakdown.
- It is used with care in people with liver problems, under medical guidance.
Monitoring
- Reviewing that symptoms are improving and that the antibiotic is clearing the infection.
- Watching for signs of an effect on the blood, such as yellowing of the skin or eyes, particularly in those at risk.
- Checking kidney function where there is any concern about it.
Side effects
- A harmless bright orange or red colouring of the urine, which can stain lenses and clothing.
- Headache, dizziness or stomach upset in some people.
- Rarely, a yellow tint to the skin or eyes, which can signal an effect on the blood or liver and needs prompt review.
- Rarely but seriously, breakdown of red blood cells, especially in people with G6PD deficiency.
Key interactions
- It can interfere with some urine tests, so tell whoever does the test that you are taking it.
- It is taken alongside an antibiotic for the infection rather than replacing it.
- Tell your prescriber about all your other medicines, particularly if you have kidney problems.
Available as: Tablets taken by mouth.
Answers
Phenazopyridine: frequently asked questions
What is phenazopyridine used for?
It is used to ease the burning, stinging and urgency of a urinary infection. It only soothes the symptoms and does not treat the infection, so it is used alongside an antibiotic.
Why has my urine turned orange?
Phenazopyridine harmlessly turns the urine a bright orange or red colour as it passes through. This is expected, but it can permanently stain contact lenses and mark clothing.
Can I use it instead of antibiotics?
No. It does not treat the infection, only the discomfort, so you still need the antibiotic your prescriber has given you to clear the infection.
How long should I take it for?
It is for short-term use only, usually just a day or two until the burning and urgency settle. It should not be taken for long periods.
Is it safe for everyone?
Not quite. It is used with caution or avoided in people with kidney problems or the inherited condition G6PD deficiency, so tell your prescriber about these.
Authoritative sources
- BNF
- NICE CKS
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