Oxaprozin

Oxaprozin tablets are 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

12.1 Mechanism of Action 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 is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. 12.3 Pharmacokinetics General Pharmacokinetic Characteristics In dose proportionality studies utilizing 600 mg, 1,200 mg and 1,800 mg doses, the pharmacokinetics of oxaprozin in healthy subjects demonstrated nonlinear kinetics of both the total and unbound drug in opposite directions, i.e., dose exposure related increase in the clearance of total drug and decrease in the clearance of the unbound drug. Decreased clearance of the unbound drug was related predominantly to a decrease in the volume of distribution of the unbound drug and not an increase in the elimination half-life. This phenomenon is considered to have minimal impact on drug accumulation upon multiple dosing. The pharmacokinetic parameters of oxaprozin in healthy subjects receiving a single dose or multiple once-daily doses of 1200 mg are presented in Table 3. Table 3. Oxaprozin Pharmacokinetic Parameters [Mean (%CV)] (1200 mg) Healthy Adults (19 to 78 years) Total Drug Unbound Drug Single N=35 Multiple N=12 Single N=35 Multiple N=12 Tmax (hr) 3.09 (39) 2.44 (40) 3.03 (48) 2.33 (35) Oral Clearance (L/hr/70 kg) 0.150 (24) 0.301 (29) 136 (24) 102 (45) Apparent Volume of Distribution at Steady State (Vd/F; L/70 kg) 11.7 (13) 16.7 (14) 6230 (28) 2420 (38) Elimination Half-life (hr) 54.9 (49) 41.4 (27) 27.8 (34) 19.5 (15) Tmax = time to reach the maximum plasma concentration of oxaprozin Absorption Oxaprozin is 95% absorbed after oral administration. Food may reduce the rate of absorption of oxaprozin, but the extent of absorption is unchanged. Antacids do not significantly affect the extent and rate of oxaprozin absorption. Distribution The apparent volume of distribution (Vd/F) of total oxaprozin is approximately 11 to 17 L/70 kg. Oxaprozin is 99% bound to plasma proteins, primarily to albumin. At therapeutic drug concentrations, the plasma protein binding of oxaprozin is saturable, resulting in a higher proportion of the free drug as the total drug concentration is increased. With increases in single doses or following multiple once-daily dosing, the apparent volume of distribution and clearance of total drug increased, while that of unbound drug decreased due to the effects of nonlinear protein binding. Oxaprozin penetrates into synovial tissues of rheumatoid arthritis patients with oxapro

2.1 General Dosing Instructions Carefully consider the potential benefits and risks of oxaprozin tablets and other treatment options before deciding to use oxaprozin tablets. Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals [see Warnings and Precautions (5)]. 2.2 Osteoarthritis For OA, the dosage is 1,200 mg (two 600 mg tablets) given orally once a day [see Dosage and Administration (2.5)]. 2.3 Rheumatoid Arthritis For RA, the dosage is 1,200 mg (two 600 mg tablets) given orally once a day [see Dosage and Administration (2.5)]. 2.4 Juvenile Rheumatoid Arthritis For JRA, in patients 6 to 16 years of age, the recommended dosage given orally once per day should be based on body weight of the patient as given in Table 1 [see Dosage and Administration (2.5)]. Table 1. Recommended Daily Dose of Oxaprozin by Body Weight in Pediatric Patients Body Weight Range (kg) Dose (mg) 22 to 31 600 32 to 54 900 ≥55 1200 2.5 Individualization of Dosage After observing the response to initial therapy with oxaprozin tablets, the dose and frequency should be adjusted to suit an individual patient’s needs. In osteoarthritis and rheumatoid arthritis and juvenile rheumatoid arthritis, the dosage should be individualized to the lowest effective dose of oxaprozin tablets to minimize adverse effects. The maximum recommended total daily dose of oxaprozin tablets in adults is 1,800 mg (26 mg/kg, whichever is lower) in divided doses. In children, doses greater than 1,200 mg have not been studied. Patients with low body weight should initiate therapy with 600 mg once daily. Patients with severe renal impairment or on dialysis should also initiate therapy with 600 mg once daily. If there is insufficient relief of symptoms in such patients, the dose may be cautiously increased to 1,200 mg, but only with close monitoring [see Clinical Pharmacology (12.3)]. In adults, in cases where a quick onset of action is important, the pharmacokinetics of oxaprozin allows therapy to be started with a one-time loading dose of 1,200 mg to 1,800 mg (not to exceed 26 mg/kg). Doses larger than 1,200 mg/day on a chronic basis should be reserved for patients who weigh more than 50 kg, have normal renal and hepatic function, are at low risk of peptic ulcer, and whose severity of disease justifies maximal therapy. Physicians should ensure that patients are tolerating doses in the 600 mg to 1,200 mg/day range without gastroenterologic, renal, hepatic, or dermatologic adverse effects before advancing to the larger doses. Most patients will tolerate once-a-day dosing with oxaprozin tablets, although divided doses may be tried in patients unable to tolerate single doses.

The following adverse reactions are discussed in greater detail in other sections of the labeling: Cardiovascular Thrombotic Events [see Warnings and Precautions (5.1)] GI Bleeding, Ulceration and Perforation [see Warnings and Precautions (5.2)] Hepatotoxicity [see Warnings and Precautions (5.3)] Hypertension [see Warnings and Precautions (5.4)] Heart Failure and Edema [see Warnings and Precautions (5.5)] Renal Toxicity and Hyperkalemia [see Warnings and Precautions (5.6)] Anaphylactic Reactions [see Warnings and Precautions (5.7)] Serious Skin Reactions [see Warnings and Precautions (5.9)] Hematologic Toxicity [see Warnings and Precautions (5.12) ] 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse reaction data were derived from patients who received oxaprozin in multidose, controlled, and open-label clinical trials. Rates for events from clinical trial experience are based on 2,253 patients who took 1,200 mg to 1,800 mg oxaprozin per day in clinical trials. Of these, 1,721 patients were treated for at least 1 month, 971 patients for at least 3 months, and 366 patients for more than 1 year. Incidence Greater than 1%: : In clinical trials of oxaprozin or in patients taking other NSAIDs, the following adverse reactions occurred at an incidence greater than 1%. Cardiovascular system: edema. Digestive system: abdominal pain/distress, anorexia, constipation, diarrhea, dyspepsia, flatulence, gastrointestinal ulcers (gastric/duodenal), gross bleeding/perforation, heartburn, liver enzyme elevations, nausea, vomiting. Hematologic system: anemia, increased bleeding time. Nervous system: CNS inhibition (depression, sedation, somnolence, or confusion), disturbance of sleep, dizziness, headache. Skin and appendages: pruritus, rash. Special senses: tinnitus. Urogenital system: abnormal renal function, dysuria or frequency. Incidence Less than 1%: : The following adverse reactions were reported in clinical trials or in patients taking other NSAIDs. Body as a whole: appetite changes, death, drug hypersensitivity reactions including anaphylaxis, fever, infection, sepsis. Cardiovascular system: arrhythmia, blood pressure changes, congestive heart failure, hypertension, hypotension, myocardial infarction, palpitations, tachycardia, syncope, vasculitis. Digestive system: alteration in taste, dry mouth, eructation, esophagitis, gastritis, glossitis, hematemesis, jaundice, liver function abnormalities including liver failure, stomatitis, hemorrhoidal or rectal bleeding. Hematologic system: aplastic anemia, ecchymoses, eosinophilia, hemolytic anemia, lymphadenopathy, melena, purpura, thrombocytopenia, leukopenia. Metabolic system: hyperglycemia, weight changes. Nervous system: anxiety, asthenia, coma, convulsions, dream abnormalities, drowsiness, hallucinations, insomnia, malaise, meningitis, nervousness, paresthesia, tremors, vertigo, weakness. Respiratory system: asthma, dyspnea, pulmonary infections, pneumonia, sinusitis, symptoms of upper respiratory tract infection, respiratory depression. Skin: alopecia, angioedema, urticaria, photosensitivity, sweat. Special senses: blurred vision, conjunctivitis, hearing decrease. Urogenital: cystitis, hematuria, increase in menstrual flow, oliguria/ polyuria, proteinuria, renal insufficiency, decreased menstrual flow. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of oxaprozin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Body as a whole: serum sickness. Digestive system: hepatitis, pancreatitis. Hematologic system: agranulocytosis, pancytopenia

5.1 Cardiovascular Thrombotic Events Clinical trials of several cyclooxygenase-2 (COX-2) selective and nonselective NSAIDs of up to three years duration have shown an increased risk of serious cardiovascular (CV) thrombotic events, including myocardial infarction (MI) and stroke, which can be fatal. Based on available data, it is unclear that the risk for CV thrombotic events is similar for all NSAIDs. The relative increase in serious CV thrombotic events over baseline conferred by NSAID use appears to be similar in those with and without known CV disease or risk factors for CV disease. However, patients with known CV disease or risk factors had a higher absolute incidence of excess serious CV thrombotic events, due to their increased baseline rate. Some observational studies found that this increased risk of serious CV thrombotic events began as early as the first weeks of treatment. The increase in CV thrombotic risk has been observed most consistently at higher doses. To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Physicians and patients should remain alert for the development of such events, throughout the entire treatment course, even in the absence of previous CV symptoms. Patients should be informed about the symptoms of serious CV events and the steps to take if they occur. There is no consistent evidence that concurrent use of aspirin mitigates the increased risk of serious CV thrombotic events associated with NSAID use. The concurrent use of aspirin and an NSAID, such as oxaprozin, increases the risk of serious gastrointestinal (GI) events [see Warnings and Precautions (5.2)]. Status Post Coronary Artery Bypass Graft (CABG) Surgery Two large, controlled clinical trials of a COX-2 selective NSAID for the treatment of pain in the first 10 to 14 days following CABG surgery found an increased incidence of myocardial infarction and stroke. NSAIDs are contraindicated in the setting of CABG [see Contraindications (4)]. Post-MI Patients Observational studies conducted in the Danish National Registry have demonstrated that patients treated with NSAIDs in the post-MI period were at increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week of treatment. In this same cohort, the incidence of death in the first year post-MI was 20 per 100 person years in NSAID-treated patients compared to 12 per 100 person years in non-NSAID exposed patients. Although the absolute rate of death declined somewhat after the first year post-MI, the increased relative risk of death in NSAID users persisted over at least the next four years of follow-up. Avoid the use of oxaprozin in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If oxaprozin is used in patients with a recent MI, monitor patients for signs of cardiac ischemia. 5.2 Gastrointestinal Bleeding, Ulceration, and Perforation NSAIDs, including oxaprozin, cause serious gastrointestinal (GI) adverse events including inflammation, bleeding, ulceration, and perforation of the esophagus, stomach, small intestine, or large intestine, which can be fatal. These serious adverse events can occur at any time, with or without warning symptoms, in patients treated with NSAIDs. Only one in five patients, who develop a serious upper GI adverse event on NSAID therapy, is symptomatic. Upper GI ulcers, gross bleeding, or perforation caused by NSAIDs occurred in approximately 1% of patients treated for 3 to 6 months, and in about 2% to 4% of patients treated for one year. However, even short-term NSAID therapy is not without risk. Risk Factors for GI Bleeding, Ulceration, and Perforation Patients with a prior history of peptic ulcer disease and/or GI bleeding who used NSAIDs had a greater than 10 times increased risk for developing a GI bleed compared to patients without these risk factors. Other facto

Oxaprozin tablets are contraindicated in the following patients: Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to oxaprozin or any components of the drug product [see Warnings and Precautions (5.7, 5.9)] History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, sometimes fatal, anaphylactic reactions to NSAIDs have been reported in such patients [see Warnings and Precautions (5.7, 5.8)] In the setting of CABG surgery [see Warnings and Precautions (5.1)]

Symptoms following acute NSAID overdosages have been typically limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which have been generally reversible with supportive care. Gastrointestinal bleeding has occurred. Hypertension, acute renal failure, respiratory depression, and coma have occurred, but were rare [see Warnings and Precautions (5.1, 5.2, 5.4, 5.6)]. Manage patients with symptomatic and supportive care following an NSAID overdosage. There are no specific antidotes. Consider emesis and/or activated charcoal (60 grams to 100 grams in adults, 1 gram to 2 grams per kg of body weight in pediatric patients) and/or osmotic cathartic in symptomatic patients seen within four hours of ingestion or in patients with a large overdosage (5 to 10 times the recommended dosage). Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding. For additional information about overdosage treatment contact a poison control center (1-800-222-1222).