Oxaprozin

Oxaprozin is indicated:

• For relief of the signs and symptoms of osteoarthritis
• For relief of the signs and symptoms of rheumatoid arthritis
• For relief of the signs and symptoms of juvenile rheumatoid arthritis

Oxaprozin, the potassium salt of oxaprozin, is a nonsteroidal anti-inflammatory drug (NSAID), which dissociates into the active moiety oxaprozin in vivo. Oxaprozin has analgesic, anti-inflammatory, and antipyretic properties.

The mechanism of action of Oxaprozin, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2).

Oxaprozin is a potent inhibitor of prostaglandin synthesis in vitro. Oxaprozin concentrations reached during therapy have produced in vivo effects. Prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain in animal models. Prostaglandins are mediators of inflammation. Because oxaprozin potassium is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues.

General Dosing Instructions: Carefully consider the potential benefits and risks of Oxaprozin and other treatment options before deciding to use Oxaprozin. Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals. After observing the response to initial therapy with Oxaprozin, the dose and frequency should be adjusted to suit an individual patient’s needs.

Divided doses may be tried in patients unable to tolerate single doses. For osteoarthritis patients of low body weight or with milder disease, an initial dose of one 600 mg tablet once a day may be appropriate. The maximum total daily dose is 1200 mg.

Osteoarthritis: For Osteoarthritis, the dosage is 1200 mg (two 600 mg tablets) given orally once a day.

Rheumatoid Arthritis: For Rheumatoid Arthritis, the dosage is 1200 mg (two 600 mg tablets) given orally once a day.

Increased risk of salicylate toxicity with aspirin. May increase effects of oral anticoagulants. May reduce effects of β-blockers, diuretics and other antihypertensive agents. May increase risk of methotrexate and lithium toxicity.

Previous or active peptic ulceration, known hypersensitivity to NSAIDs. Perioperative pain in CABG setting.

Common side effects are depression, sedation, somnolence, confusion, disturbance of sleep, weakness, malaise; rash, prutitus, urticaria, photosensitivity; abdominal pain/distress, anorexia, flatulence, vomiting, constipation, diarrhoea, dyspepsia, nausea, peptic ulcer and/or GI bleeding, abnormalities in LFTs, stomatitis, haemorrhoidal or rectal bleeding; tinnitus; dysuria or frequency; oedema, BP changes; haematuria, renal insufficiency, decreased menstrual flow; anaemia, thrombocytopenia, leukopenia, ecchymoses; wt gain/loss; blurred vision, conjunctivitis.

The following adverse reactions may occur:

• Cardiovascular Thrombotic Events 
• GI Bleeding, Ulceration and Perforation 
• Hepatotoxicity 
• Hypertension 
• Heart Failure and Edema 
• Renal Toxicity and Hyperkalemia
• Anaphylactic Reactions
• Serious Skin Reactions 
• Hematologic Toxicity 

Pregnancy categaory: C, D (in 3rd trimester or near delivery).

Be alert for ulceration and bleeding in patients treated chronically. History of serious GI events, alcoholism, smoking, other factors known to be associated with peptic ulcer. Elderly or debilitated patients. Uncompensated cardiac failure, history of hypertension, cardiac decompensation, chronic diuretic therapy, conditions predisposing to fluid retention. Renal and hepatic impairment. Underlying coagulation defects or patients who are undergoing surgical procedures where a high degree of haemostasis is required. Pregnancy (avoid in 3rd trimester) and lactation.

Symptoms: Acute renal failure, vomiting, drowsiness, leukocytosis.

Management: Supportive and symptomatic. Multiple admin of charcoal may be required to reduce potential for delayed toxicities.

Drugs for Osteoarthritis, Drugs used for Rheumatoid Arthritis, Non-steroidal Anti-inflammatory Drugs (NSAIDs).

Renal Impairment-

Osteoarthritis: Severe or on dialysis: 600 mg once daily. Increase to 1.2 g daily if needed.
Rheumatoid arthritis: Severe or on dialysis: 600 mg once daily. Increase to 1.2 g daily if needed.

Store at 25° C. Protect from light.