Oxaprozin

Indications

Oxaprozin is used for: Rheumatoid arthritis, Osteoarthritis, Juvenile rheumatoid arthritis

Adult Dose

Osteoarthritis Initial in mild to moderate disease: 600mg PO qDay Usual in moderate to severe disease: 1200mg PO qDay Maximum 1,800 mg/day or 26 mg/kg/day, whichever is lower, divided PO q12hr Rheumatoid Arthritis 1200mg PO qDay (individualize) Maximum 1,800 mg/day or 26 mg/kg/day, whichever is lower, divided PO q12hr Hepatic Impairment Caution in patients with severe liver impairment

Child Dose

Juvenile Rheumatoid Arthritis <6 years Safety and efficacy not established >6 years 22-31 kg: 600 mg PO qDay 32-54 kg: 900 mg PO qDay >55 kg: 1200 mg PO qDay

Renal Dose

Renal Impairment Severe renal impairment or on dialysis: 600 mg PO qDay; may increase to 1200 mg/day; monitor closely

Administration

Take with food or water to avoid GI effects

Contra Indications

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

Precautions

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. Lactation: not known whether excreted in breast milk; effect on infant unknown

Pregnancy-Lactation

Pregnancy Category: C; D in 3rd trimester or near delivery.

Interactions

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

Adverse Effects

Side effects of Oxaprozin : Common Edema, Rash, Abdominal pain, Anorexia, Constipation, Diarrhea, Indigestion, Nausea/Vomiting, GI ulcer, Gross bleeding with perforation, Heartburn, Anemia, LFT's increased.Tinnitus, Dysuria, Increased frequency of urination, Myocardial infarction (<2%) <1% Hypertension (<1%), Palpitations (<1%), Thrombotic tendency observations, Erythema multiforme (rare), Scaling eczema, Stevens-Johnson syndrome (rare), Toxic epidermal necrolysis (rare), Cerebrovascular accident, Gastrointestinal hemorrhage (<1%), Agranulocytosis (rare), Leukopenia (<1%), Thrombocytopenia (<1%), Hepatitis (rare), Jaundice, Liver failure, Anaphylactoid reaction (<1%), Amblyopia (<1%), Hearing loss (<1%), Acute renal failure (rare), Hematuria (rare), Interstitial nephritis (rare), Bronchospasm, Serum sickness due to drug (rare) Potentially Fatal: Anaphylactoid reactions, exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, severe hepatic reactions.

Mechanism of Action

Oxaprozin is a propionic acid derivative NSAID. It inhibits the enzyme cyclooxygenase resulting in the blockage of prostaglandin synthesis.