Oxaprozin belongs to a class of medications called nonsteroidal anti-inflammatory drugs (NSAIDs). It reduces pain, stiffness, and inflammation associated with rheumatoid arthritis and osteoarthritis.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose ranges from 600 mg daily to 1,800 mg daily taken in 1 or 2 doses with food or milk. If you are taking 1,800 mg daily, it should be divided into two doses: a 1,200 mg dose in the morning and a 600 mg dose in the evening.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not take this mediction if you:

• are or may be allergic to oxaprozin or to any of the ingredients of the medication
• are breast-feeding
• are currently taking other NSAIDs
• are in the third trimester of pregnancy
• are planning to have or recently had heart bypass surgery
• are under 18 years of age
• currently have or recently had an inflammatory disease of the stomach and intestines such as stomach or intestinal ulcer or ulcerative colitis
• have a history of significant liver or kidney disease
• have bleeding in the brain or a bleeding disorder
• have had an allergic reaction to ASA or any other anti-inflammatory medications
• have high levels of potassium in the blood
• have severe uncontrolled heart failure

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal or stomach cramps, pain, or discomfort (mild to moderate)
• diarrhea
• drowsiness
• heartburn, indigestion, nausea, or vomiting
• bloated feeling, gas, or constipation
• decreased appetite or loss of appetite
• ringing in the ears
• trouble sleeping

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Stop taking the medication and check with your doctor as soon as possible if any of the following side effects occur:

• depression or mental confusion
• dizziness or lightheadedness
• headache (severe) or stiff neck
• hearing problems
• pain or difficulty when urinating
• persistent nausea, stomach pain, diarrhea, or indigestion
• sun sensitivity reaction (sunburn, skin blisters or rash, skin itching or discolouration, or vision changes)
• swelling of feet and lower legs
• symptoms of liver problems (such as yellow skin or eyes, dark urine, pale stools, abdominal pain, or itchy skin)
• unexplained weight gain
• vomiting

Stop taking the medication and seek immediate medical attention if any of the following occur:

• blurred vision or vision changes
• changes in the amount or colour of urine (e.g., red, brown)
• chills, fever, muscle aches or pains, or other flu-like symptoms (especially if they occur together with a skin rash)
• dark, bloody, or black tarry stools
• shortness of breath, wheezing, any trouble in breathing, or chest tightness
• skin rash, itching, hives, or swelling
• unexpected weakness
• vomiting blood

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Dizziness/headaches: Headaches, sometimes accompanied by dizziness or lightheadedness, may occur during treatment with oxaprozin. (These headaches usually occur early in the treatment.) Your doctor may recommend that you take a lower dose to reduce headaches and dizziness. If this does not work, your doctor may recommend that you stop taking oxaprozin. Avoid operating motor vehicles and doing other potentially hazardous activities until you determine the effect this medication has on you.

Drowsiness/reduced awareness: Some people have reported headaches, dizziness, lightheadedness, and confusion while taking this medication. Avoid operating motor vehicles and doing other potentially hazardous activities until you have determined the effect this medication has on you.

Fluid and electrolyte balance: Fluid retention and edema (swelling, usually in the feet and lower legs) have been reported with use of this medication. The risk may be higher in people who are recovering from surgery under general anesthesia, have congestive heart failure, have high blood pressure, or have kidney disease. There is also a risk of high blood potassium with oxaprozin treatment. People most at risk are:

• seniors
• people with conditions such as diabetes or kidney failure
• people who are taking beta-adrenergic blockers, angiotensin converting enzyme (ACE) inhibitors, or some diuretics (water pills).

If you have any of these risk factors, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Gastrointestinal effects: Stomach ulcers, perforation, and bleeding from the stomach have been known to occur during therapy with oxaprozin. These complications can occur at any time, and are sometimes severe enough to require immediate medical attention. The risk of ulcers and bleeding is increased in people taking higher doses of oxaprozin for longer periods of time. Stop taking the medication and contact your doctor immediately if you experience symptoms or signs of stomach ulcers or bleeding in the stomach (black, tarry stools). These reactions can occur at any time during treatment without warning.

Heart problems: Like other NSAID medications, oxaprozin may increase the risk of heart attacks, strokes, and blood clots. The risk is greater with higher doses and long-term use.

Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed, if you have a condition that puts you at risk of heart problems, for example:

• coronary artery disease
• diabetes
• heart failure
• high blood pressure
• high cholesterol
• peripheral arterial disease
• reduced kidney function

Infection: This medication may mask the signs of an infection, such as a fever.

Kidney function: Long-term use of oxaprozin may lead to a higher risk of reduced kidney function. This is most common for people who already have kidney disease, liver disease, or heart failure; for people who take diuretics (water pills); and for seniors.

Liver function: This medication may cause liver problems. If you have a liver condition, you may need more frequent check-ups with your doctor. If you develop signs of a liver problem (such as yellow skin or eyes, dark urine, pale stools, abdominal pain, or itchy skin), stop taking the medication and see your doctor as soon as possible.

Sun sensitivity: This medication may make your skin more sensitive to the sun. While you are using this medication, avoid excessive sun exposure, including tanning beds and sun lamps. If you experience sunburn with itching, swelling, and blistering, stop using this medication and contact your doctor.

Pregnancy: This medication should not be used during the third trimester of pregnancy. It should not be used during the first or second trimesters of pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: Oxaprozin should not be used during breast-feeding because many NSAIDs have been shown to pass into breast milk.

Children: The safety and effectiveness of using this medication have not been established for children. Oxaprozin is not recommended for children and adolescents under the age of 18 years.

Seniors: Seniors appear to have a higher risk of side effects. They should use the lowest effective dosage under close medical supervision.

There may be an interaction between oxaprozin and any of the following:

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.