A long-acting anti-inflammatory painkiller (NSAID)
Oxaprozin
A long-acting anti-inflammatory painkiller used mainly for arthritis, taken once a day.
What is Oxaprozin?
Oxaprozin is a non-steroidal anti-inflammatory medicine (an NSAID) used mainly to relieve pain and stiffness in arthritis. It is long-acting, so it is usually taken once a day. Like other NSAIDs, it can irritate the stomach and cause ulcers or bleeding, can affect the kidneys, and carries a small increased risk of heart attack and stroke, particularly at higher doses or with long-term use. It can also make the skin more sensitive to sunlight. It is largely a US product rather than one routinely used in the UK, and is taken at the lowest effective amount for the shortest time.
Education and reference only. This is a plain-language guide to Oxaprozin — 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
Oxaprozin is a non-steroidal anti-inflammatory drug, a group of medicines that ease pain and reduce inflammation. It is used mainly for arthritis, such as osteoarthritis and rheumatoid arthritis, to relieve pain, swelling and stiffness. Its main feature is that it is long-acting, so it can be taken just once a day. It is largely a US product and is not a routine choice in the UK, where other NSAIDs are more commonly used, but it works in the same way and shares the same family of cautions.
How it works
Oxaprozin works by blocking enzymes called cyclo-oxygenase (COX), which the body uses to make prostaglandins, the chemicals that drive pain, swelling and fever. Reducing prostaglandins eases the pain and inflammation of arthritis. Because the same prostaglandins help protect the stomach lining and support kidney blood flow, blocking them can cause stomach irritation and affect the kidneys. Its long-lasting action in the body means it can be taken once a day, but it also means its effects and any side effects persist for longer than with shorter-acting NSAIDs.
Company & origin
Originated / developed by: Various manufacturers.
A long-acting non-steroidal anti-inflammatory medicine used mainly for arthritis; it is largely a US product rather than a routine UK one.
What it treats
Conditions Oxaprozin is used for
Practical use
How to take Oxaprozin
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it once a day with or after food to reduce the chance of stomach upset.
- Use the lowest amount that controls your symptoms for the shortest time needed.
- Protect your skin from strong sunlight, as it can make the skin more sensitive to the sun.
- Tell your pharmacist or doctor about other medicines, as some combinations increase the risk of bleeding or kidney problems.
- Get medical advice before taking it if you have stomach, heart, kidney or liver problems.
Weighing it up
Advantages & disadvantages of Oxaprozin
Advantages
- Relieves pain, swelling and stiffness in arthritis.
- Long-acting, so it can usually be taken just once a day.
- Works in the same well-understood way as other NSAIDs.
Disadvantages
- Can irritate the stomach and, less commonly, cause ulcers or bleeding.
- Can affect the kidneys and carries a small increased risk of heart attack and stroke.
- Can increase skin sensitivity to sunlight, and because it is long-acting, side effects can persist.
Practical use
Good to know
Oxaprozin is usually taken once a day with or after food to lower the chance of stomach upset, and it is used at the lowest dose that helps for the shortest time needed. The main safety points are shared by NSAIDs: it can irritate the stomach and, less commonly, cause ulcers or bleeding, it can affect the kidneys, and it carries a small increased risk of heart attack and stroke, especially at higher doses or with long-term use. It can also raise blood pressure and cause fluid retention. A particular feature is that it can make the skin more sensitive to sunlight, so sun protection is sensible. Because it is long-acting, side effects can last longer once they start. Tell your prescriber about other medicines, as combining NSAIDs with blood thinners, steroids or some blood-pressure medicines increases risks, and get advice first if you have stomach, heart, kidney or liver problems or are pregnant.
Who should not take it / use with caution
- People who have had a serious allergic reaction, asthma attack or skin reaction to oxaprozin, aspirin or other NSAIDs should not use it.
- People with a current or past stomach ulcer or bleeding from NSAIDs should usually avoid it.
- It is generally avoided in severe heart, kidney or liver failure, and in the later part of pregnancy.
- It is used with caution in older people and those with heart disease, high blood pressure or asthma.
Monitoring
- Reviewing whether it is still needed and using it for the shortest time.
- Checking blood pressure and kidney function with longer-term use.
- Watching for signs of stomach bleeding, such as black stools or vomiting blood.
Side effects
- Indigestion, stomach pain, nausea or diarrhoea.
- Increased skin sensitivity to sunlight.
- Less commonly, stomach ulcers or bleeding, which can cause black stools or vomiting blood and need urgent care.
- Rarely, kidney problems, raised blood pressure, fluid retention, or serious allergic or skin reactions.
Key interactions
- Other NSAIDs, including aspirin, and steroids increase the risk of stomach irritation and bleeding.
- Blood thinners such as warfarin or DOACs increase the risk of bleeding when combined with it.
- It can reduce the effect of some blood-pressure medicines and water tablets, and increase the risk of kidney problems with ACE inhibitors or diuretics.
Available as: Tablets taken by mouth.
Answers
Oxaprozin: frequently asked questions
What is oxaprozin used for?
It is a long-acting anti-inflammatory painkiller used mainly to relieve pain, swelling and stiffness in arthritis, taken once a day.
Why is it taken only once a day?
It is long-acting and stays in the body for a long time, so a single daily dose is usually enough to control symptoms.
Does it make the skin sensitive to the sun?
Yes, it can increase the skin's sensitivity to sunlight, so it is sensible to protect your skin and avoid strong sun while taking it.
Can it affect my stomach, heart or kidneys?
Like other NSAIDs it can irritate the stomach and cause ulcers or bleeding, affect the kidneys, and carries a small increased risk of heart attack and stroke.
Is oxaprozin used in the UK?
It is largely a US product and is not a routine choice in the UK, where other NSAIDs are more commonly used, although it works in the same way.
The wider class
About Non-steroidal anti-inflammatory drug (NSAID)
Oxaprozin belongs to the non-steroidal anti-inflammatory drug (nsaid) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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