Celecoxib

12.1 Mechanism of Action Celecoxib has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of celecoxib is believed to be due to inhibition of prostaglandin synthesis, primarily via inhibition of COX-2. Celecoxib is a potent inhibitor of prostaglandin synthesis in vitro . Celecoxib 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. Since celecoxib is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues.

1. INDICATIONS AND USAGE Celecoxib is indicated Celecoxib is a nonsteroidal anti-inflammatory drug indicated for: Osteoarthritis (OA) ( 1.1 ) Rheumatoid Arthritis (RA) ( 1.2 ) Juvenile Rheumatoid Arthritis (JRA) in patients 2 years and older ( 1.3 ) Ankylosing Spondylitis (AS) ( 1.4 ) Acute Pain (AP) ( 1.5 ) Primary Dysmenorrhea (PD) ( 1.6 ) 1.1 Osteoarthritis For the management of the signs and symptoms of OA [ see Clinical Studies (14.1) ]. 1.2 Rheumatoid Arthritis For the management of the signs and symptoms of RA [ see Clinical Studies (14.2) ]. 1.3 Juvenile Rheumatoid Arthritis For the management of the signs and symptoms of JRA in patients 2 years and older [ see Clinical Studies (14.3) ]. 1.4 Ankylosing Spondylitis For the management of the signs and symptoms of AS [ see Clinical Studies (14.4) ]. 1.5 Acute Pain For the management of acute pain in adults [ see Clinical Studies (14.5) ]. 1.6 Primary Dysmenorrhea For the management of primary dysmenorrhea [ see Clinical Studies (14.5) ].

2. DOSAGE AND ADMINISTRATION Use the lowest effective dosage for shortest duration consistent with individual patient treatment goals. ( 2.1 ) OA: 200 mg once daily or 100 mg twice daily. ( 2.2 , 14.1 ) RA: 100 mg to 200 mg twice daily. ( 2.3 , 14.2 ) JRA: 50 mg twice daily in patients 10 kg to 25 kg. 100 mg twice daily in patients more than 25 kg. ( 2.4 , 14.3 ) AS: 200 mg once daily single dose or 100 mg twice daily. If no effect is observed after 6 weeks, a trial of 400 mg (single or divided doses) may be of benefit. ( 2.5 , 14.4 ) AP and PD: 400 mg initially, followed by 200 mg dose if needed on first day. On subsequent days, 200 mg twice daily as needed. ( 2.6 , 14.5 ) Hepatic Impairment: Reduce daily dose by 50% in patients with moderate hepatic impairment (Child-Pugh Class B). ( 2.7 , 8.6 , 12.3 ) Poor Metabolizers of CYP2C9 Substrates: Consider a dose reduction by 50% (or alternative management for JRA) in patients who are known or suspected to be CYP2C9 poor metabolizers. ( 2.7 , 8.8 , 12.3 ). 2.1 General Dosing Instructions Carefully consider the potential benefits and risks of celecoxib and other treatment options before deciding to use celecoxib. Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals [ see Warnings and Precautions (5) ]. These doses can be given without regard to timing of meals. 2.2 Osteoarthritis For OA, the dosage is 200 mg per day administered as a single dose or as 100 mg twice daily. 2.3 Rheumatoid Arthritis For RA, the dosage is 100 mg to 200 mg twice daily. 2.4 Juvenile Rheumatoid Arthritis For JRA, the dosage for pediatric patients (age 2 years and older) is based on weight. For patients > 10 kg to < 25 kg the recommended dose is 50 mg twice daily. For patients >25 kg the recommended dose is 100 mg twice daily. For patients who have difficulty swallowing capsules, the contents of a celecoxib capsule can be added to applesauce. The entire capsule contents are carefully emptied onto a level teaspoon of cool or room temperature applesauce and ingested immediately with water. The sprinkled capsule contents on applesauce are stable for up to 6 hours under refrigerated conditions (2°C to 8°C/ 35°F to 45°F). 2.5 Ankylosing Spondylitis For AS, the dosage of celecoxib capsule is 200 mg daily in single (once per day) or divided (twice per day) doses. If no effect is observed after 6 weeks, a trial of 400 mg daily may be worthwhile. If no effect is observed after 6 weeks on 400 mg daily, a response is not likely and consideration should be given to alternate treatment options. 2.6 Management of Acute Pain and Treatment of Primary Dysmenorrhea For management of Acute Pain and Treatment of Primary Dysmenorrhea, the dosage is 400 mg initially, followed by an additional 200 mg dose if needed on the first day. On subsequent days, the recommended dose is 200 mg twice daily as needed. 2.7 Special Populations Hepatic Impairment In patients with moderate hepatic impairment (Child-Pugh Class B), reduce the dose by 50%. The use of celecoxib in patients with severe hepatic impairment is not recommended [ see Warnings and Precautions (5.3) , Use in Specific Populations (8.6) , and Clinical Pharmacology (12.3) ] . Poor Metabolizers of CYP2C9 Substrates In adult patients who are known or suspected to be poor CYP2C9 metabolizers based on genotype or previous history/experience with other CYP2C9 substrates (such as warfarin, phenytoin), initiate treatment with half of the lowest recommended dose. In patients with JRA who are known or suspected to be poor CYP2C9 metabolizers, consider using alternative treatments [ see Use in Specific populations (8.8) and Clinical Pharmacology (12.5) ].

6. ADVERSE REACTIONS 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 ) ] Most common adverse reactions in arthritis trials (>2% and > placebo) are: abdominal pain, diarrhea, dyspepsia, flatulence, peripheral edema, accidental injury, dizziness, pharyngitis, rhinitis, sinusitis, upper respiratory tract infection, rash. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Micro Labs USA, Inc. at 1-855-839-8195 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 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. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates. Of the celecoxib-treated patients in the pre-marketing controlled clinical trials, approximately 4,250 were patients with OA, approximately 2,100 were patients with RA, and approximately 1,050 were patients with post-surgical pain. More than 8,500 patients received a total daily dose of celecoxib of 200 mg (100 mg twice daily or 200 mg once daily) or more, including more than 400 treated at 800 mg (400 mg twice daily). Approximately 3,900 patients received celecoxib at these doses for 6 months or more; approximately 2,300 of these have received it for 1 year or more and 124 of these have received it for 2 years or more. Pre-marketing Controlled Arthritis Trials Table 1 lists all adverse events, regardless of causality, occurring in ≥ 2% of patients receiving celecoxib from 12 controlled studies conducted in patients with OA or RA that included a placebo and/or a positive control group. Since these 12 trials were of different durations, and patients in the trials may not have been exposed for the same duration of time, these percentages do not capture cumulative rates of occurrence. Table 1: Adverse Events Occurring in ≥2% of Celecoxib Patients from Pre-marketing Controlled Arthritis Trials CBX N=4146 Placebo N=1864 NAP N=1366 DCF N=387 IBU N=345 Gastrointestinal Abdominal Pain 4.1% 2.8% 7.7% 9.0% 9.0% Diarrhea 5.6% 3.8% 5.3% 9.3% 5.8% Dyspepsia 8.8% 6.2% 12.2% 10.9% 12.8% Flatulence 2.2% 1.0% 3.6% 4.1% 3.5% Nausea 3.5% 4.2% 6.0% 3.4% 6.7% Body as a whole Back Pain 2.8% 3.6% 2.2% 2.6% 0.9% Peripheral Edema 2.1% 1.1% 2.1% 1.0% 3.5% Injury-Accidental 2.9% 2.3% 3.0% 2.6% 3.2% Central, Peripheral Nervous system Dizziness 2.0% 1.7% 2.6% 1.3% 2.3% Headache 15.8% 20.2% 14.5% 15.5% 15.4% Psychiatric Insomnia 2.3% 2.3% 2.9% 1.3% 1.4% Respiratory Pharyngitis 2.3% 1.1% 1.7% 1.6% 2.6% Rhinitis 2.0% 1.3% 2.4% 2.3% 0.6% Sinusitis 5.0% 4.3% 4.0% 5.4% 5.8% Upper Respiratory Infection 8.1% 6.7% 9.9% 9.8% 9.9% Skin Rash 2.2% 2.1% 2.1% 1.3% 1.2% CBX = Celecoxib capsule 100 mg to 200 mg twice daily or 200 mg once daily; NAP = Naproxen 500 mg twice daily; DCF = Diclofenac 75 mg twice daily; IBU = Ibuprofen 800 mg three times daily. In placebo- or active-controlled clinical trials, the discontinuation rate due to adverse events was 7.1% for patients receiving celecoxib and 6.1% for patients receiving placebo. Among the most common reasons for discontinuation due to adverse events in the celecoxib treatment groups were dyspepsia and abdominal pain (cited as reasons for discontinuation in 0.8% and 0.7% of celecoxib patients, respectively). Among patients receiving placebo, 0.6% discontinued due to dyspepsia and 0.6% withdrew due to abdominal pain. The following adverse reactions occurred in 0.1% to 1.9% of patients treated with celecoxib capsule (100 mg to 200 mg twice daily or 200 mg once daily): Gastrointestinal : Constipation, diverticulitis, dysphagia, eructation, esophagitis, gastritis, gastroenteritis, gastroesophageal reflux, hemorrhoids, hiatal hernia, melena, dry mouth, stomatitis, tenesmus, vomiting Cardiovascular: Aggravated hypertension, angina pectoris, coronary artery disorder, myocardial infarction General : Hypersensitivity, allergic reaction, chest pain, cyst NOS, edema generalized, face edema, fatigue, fever, hot flushes, influenza- like symptoms, pain, peripheral pain Central, peripheral nervous system: Leg cramps, hypertonia, hypoesthesia, migraine, paresth

7. DRUG INTERACTIONS See Table 3 for clinically significant drug interactions with celecoxib. Table 3: Clinically Significant Drug Interactions with Celecoxib Drugs That Interfere with Hemostasis Clinical Impact: Celecoxib and anticoagulants such as warfarin have a synergistic effect on bleeding. The concomitant use of celecoxib and anticoagulants have an increased risk of serious bleeding compared to the use of either drug alone. Serotonin release by platelets plays an important role in hemostasis. Case-control and cohort epidemiological studies showed that concomitant use of drugs that interfere with serotonin reuptake and an NSAID may potentiate the risk of bleeding more than an NSAID alone. Intervention: Monitor patients with concomitant use of celecoxib with anticoagulants (e.g., warfarin), antiplatelet drugs (e.g., aspirin), SSRIs, and SNRIs for signs of bleeding [see Warnings and Precautions (5.12) ]. Aspirin Clinical Impact: Controlled clinical studies showed that the concomitant use of NSAIDs and analgesic doses of aspirin does not produce any greater therapeutic effect than the use of NSAIDs alone. In a clinical study, the concomitant use of an NSAID and aspirin was associated with a significantly increased incidence of GI adverse reactions as compared to use of the NSAID alone [ see Warnings and Precautions (5.2) ]. In two studies in healthy volunteers, and in patients with osteoarthritis and established heart disease respectively, celecoxib (200 mg to 400 mg daily) has demonstrated a lack of interference with the cardioprotective antiplatelet effect of aspirin (100 mg to 325 mg). Intervention: Concomitant use of celecoxib and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding [see Warnings and Precautions (5.12) ]. Celecoxib is not a substitute for low dose aspirin for cardiovascular protection. ACE Inhibitors, Angiotensin Receptor Blockers, and Beta-Blockers Clinical Impact: NSAIDs may diminish the antihypertensive effect of ACE inhibitors, ARBs, or beta-blockers (including propranolol). In patients who are elderly, volume-depleted (including those on diuretic therapy), or have renal impairment, co-administration of an NSAID with ACE inhibitors or ARBs may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Intervention: During concomitant use of celecoxib and ACE inhibitors, ARBs, or beta-blockers, monitor blood pressure to ensure that the desired blood pressure is obtained. During concomitant use of celecoxib and ACE inhibitors or ARBs in patients who are elderly, volume-depleted, or have impaired renal function, monitor for signs of worsening renal function [ see Warnings and Precautions (5.6) ]. When these drugs are administered concomitantly, patients should be adequately hydrated. Assess renal function at the beginning of the concomitant treatment and periodically thereafter. Diuretics Clinical Impact: Clinical studies, as well as post-marketing observations, showed that NSAIDs reduced the natriuretic effect of loop diuretics (e.g., furosemide) and thiazide diuretics in some patients. This effect has been attributed to the NSAID inhibition of renal prostaglandin synthesis. Intervention: During concomitant use of celecoxib with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects [ see Warnings and Precautions (5.6) ]. Digoxin Clinical Impact: The concomitant use of Celecoxib with digoxin has been reported to increase the serum concentration and prolong the half-life of digoxin. Intervention: During concomitant use of celecoxib and digoxin, monitor serum digoxin levels. Lithium Clinical Impact: NSAIDs have produced elevations in plasma lithium levels and reductions in renal lithium clearance . The mean minimum lithium concentration increased 15%, and the renal clearance decreased by approximately 20%. This effect has been attributed to NSAID inhibition of renal prostaglandin synthesis. Intervention: During concomitant use of celecoxib and lithium, monitor patients for signs of lithium toxicity. Methotrexate Clinical Impact: Concomitant use of NSAIDs and methotrexate may increase the risk for methotrexate toxicity (e.g., neutropenia, thrombocytopenia, renal dysfunction). Celecoxib has no effect on methotrexate pharmacokinetics. Intervention: During concomitant use of celecoxib and methotrexate, monitor patients for methotrexate toxicity. Cyclosporine Clinical Impact: Concomitant use of celecoxib and cyclosporine may increase cyclosporine’s nephrotoxicity. Intervention: During concomitant use of celecoxib and cyclosporine, monitor patients for signs of worsening renal function. NSAIDs and Salicylates Clinical Impact: Concomitant use of Celecoxib with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity, with little or no increase in efficacy [ see Wa