Diclofenac Sodium, Capsaicin

1 INDICATIONS AND USAGE Diclofenac sodium topical solution, USP is indicated for the treatment of signs and symptoms of osteoarthritis of the knee(s) (1). Diclofenac sodium topical solution is a nonsteroidal anti-inflammatory drug indicated for the treatment of signs and symptoms of osteoarthritis of the knee(s). ( 1 )

2 DOSAGE AND ADMINISTRATION Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals. The recommended dose is 40 drops on each painful knee, 4 times a day. ( 2 ) Apply diclofenac sodium topical solution to clean, dry skin. ( 2.1 ) Dispense diclofenac sodium topical solution 10 drops at a time either directly onto the knee or first into the hand and then onto the knee. Spread diclofenac sodium topical solution evenly around front, back and sides of the knee. Repeat this procedure until 40 drops have been applied and the knee is completely covered with solution. ( 2.1 ) Wash hands completely after administering the product. Wait until the area is completely dry before covering with clothing or applying sunscreen, insect repellent, cosmetics, topical medications, or other substances. Until the treated knee(s) is completely dry, avoid skin-to-skin contact between other people and the treated knee(s). ( 2.2 ) Do not get diclofenac sodium topical solution in your eyes, nose or mouth. 2.1 General Dosing Instructions Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals [ see Warning and Precautions (5.2) ]. For the relief of the signs and symptoms of osteoarthritis of the knee(s), the recommended dose is 40 drops per knee, 4 times a day. Apply diclofenac sodium topical solution to clean, dry skin. To avoid spillage, dispense diclofenac sodium topical solution 10 drops at a time either directly onto the knee or first into the hand and then onto the knee. Spread diclofenac sodium topical solution evenly around front, back and sides of the knee. Repeat this procedure until 40 drops have been applied and the knee is completely covered with solution. To treat the other knee, if symptomatic, repeat the procedure. Application of diclofenac sodium topical solution in an amount exceeding or less than the recommended dose has not been studied and is therefore not recommended. 2.2 Special Precautions Avoid showering/bathing for at least 30 minutes after the application of diclofenac sodium topical solution to the treated knee. Wash and dry hands after use. Do not apply diclofenac sodium topical Solution USP, to open wounds. Avoid contact of diclofenac sodium topical solution with eyes and mucous membranes. Do not apply external heat and/or occlusive dressings to treated knees. Avoid wearing clothing over the diclofenac sodium topical solution treated knee(s) until the treated knee is dry. Protect the treated knee(s) from natural or artificial sunlight. Wait until the treated area is dry before applying sunscreen, insect repellant, lotion, moisturizer, cosmetics, or other topical medication to the same knee you have just treated with diclofenac sodium topical solution. Until the treated knee(s) is completely dry, avoid skin-to-skin contact between other people and the treated knee(s). Do not use combination therapy with diclofenac sodium and an oral NSAID unless the benefit outweighs the risk and conduct periodic laboratory evaluations.

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) ] The most common adverse reactions with diclofenac sodium topical solution are application site reactions. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Taro Pharmaceuticals U.S.A., Inc. at 1-866-923-4914 or the 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 data described below reflect exposure to diclofenac sodium topical solution of 911 patients treated between 4 and 12 weeks (mean duration of 49 days) in seven Phase 3 controlled trials, as well as exposure of 793 patients treated in an open-label study, including 463 patients treated for at least 6 months, and 144 patients treated for at least 12 months. The population mean age was approximately 60 years, 89% of patients were Caucasians, 64% were females, and all patients had primary osteoarthritis. The most common adverse events with diclofenac sodium topical solution were application site skin reactions. These events were the most common reason for withdrawing from the studies. Application Site Reactions In controlled trials, the most common treatment-related adverse events in patients receiving diclofenac sodium topical solution were application site skin reactions. Application site reactions were characterized by one or more of the following: dryness, erythema, induration, vesicles, paresthesia, pruritus, vasodilation, acne, and urticaria. The most frequent of these reactions were dry skin (32%), contact dermatitis characterized by skin erythema and induration (9%), contact dermatitis with vesicles (2%) and pruritus (4%). In one controlled trial, a higher rate of contact dermatitis with vesicles (4%) was observed after treatment of 152 subjects with the combination of diclofenac sodium topical solution and oral diclofenac. In the open label uncontrolled long-term safety study, contact dermatitis occurred in 13% and contact dermatitis with vesicles in 10% of patients, generally within the first 6 months of exposure, leading to a withdrawal rate for an application site event of 14%. Adverse Events Common to the NSAID Class In controlled trials, subjects treated with diclofenac sodium topical solution experienced some adverse events associated with the NSAID class more frequently than subjects using placebo (constipation, diarrhea, dyspepsia, nausea, flatulence, abdominal pain, edema; see Table 1 ). The combination of diclofenac sodium topical solution and oral diclofenac, compared to oral diclofenac alone, resulted in a higher rate of rectal hemorrhage (3% vs. less than 1%), and more frequent abnormal creatinine (12% vs. 7%), urea (20% vs. 12%), and hemoglobin (13% vs. 9%), but no difference in elevation of liver transaminases. Table 1 lists all adverse reactions occurring in ≥1% of patients receiving diclofenac sodium topical solution, where the rate in the diclofenac sodium topical solution group exceeded placebo, from seven controlled studies conducted in patients with osteoarthritis. Since these trials were of different durations, these percentages do not capture cumulative rates of occurrence. Table 1: Adverse Reactions Occurring in ≥1% of Patients Treated with Diclofenac Sodium Topical Solution in Placebo and Oral diclofenac-controlled trials. Treatment Group: Diclofenac Sodium Topical Solution N=911 Topical Placebo N=332 Adverse Reaction Preferred Term according to COSTART N (%) N (%) Dry Skin (Application Site) 292 (32) 17 (5) Contact Dermatitis (Application Site) 83 (9) 6 (2) Dyspepsia 72 (8) 13 (4) Abdominal Pain 54 (6) 10 (3) Flatulence 35 (4) 1 (<1) Pruritus (Application Site) 34 (4) 7 (2) Diarrhea 33 (4) 7 (2) Nausea 33 (4) 3 (1) Pharyngitis 40 (4) 13 (4) Constipation 29 (3) 1 (<1) Edema 26 (3) 0 Rash (Non-Application Site) 25 (3) 5 (2) Infection 25 (3) 8 (2) Ecchymosis 19 (2) 1 (<1) Dry Skin (Non-Application Site) 19 (2) 1 (<1) Contact Dermatitis, vesicles (Application Site) 18 (2) 0 Paresthesia (Non-Application Site) 14 (2) 3 (<1) Accidental Injury 22 (2) 7 (2) Pruritis (Non-Application Site) 15 (2) 2 (<1) Sinusitis 10 (1) 2 (<1) Halitosis 11 (1) 1 (<1) Application Site Reaction (not otherwise specified) 11 (1) 3 (<1) 6.2 Postmarketing Experience In non-U.S. postmarketing surveillance, the following adverse reactions have been reported during post-approval use of diclofenac sodium topical solution. 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: abdominal pain, accidental injury, allergic reaction, asthenia, back pain, body odor, chest pain, edema, face edema, halitosis, headache, lack of drug effect, neck rigidity, pain Cardiovascular: palpitation, cardiovascular disorder Digestive: diarrhea, dry mouth, dyspepsia, gastroenteritis, decreased appetite, mouth ulceration, nausea, rectal hemorrhage, ulcerative stomatitis Metabolic and Nutritional: creatinine increased Musculoskeletal: leg cramps, myalgia Nervous: depression, dizziness, drowsiness, lethargy, paresthesia, paresthesia at application site Respiratory: asthma, dyspnea, laryngismus, laryngitis, pharyngitis Skin and Appendages: At the Application Site: contact dermatitis, contact dermatitis with vesicles, dry skin, pruritus, rash; Other Skin and Appendages Adverse Reactions: eczema, rash, pruritus, skin discoloration, urticaria Special Senses: abnormal vision, blurred vision, cataract, ear pain, eye disorder, eye pain, taste perversion

12.3 Pharmacokinetics After topical administration to healthy human volunteers of single and multiple maximum doses of diclofenac sodium topical solution, 40 drops (approximately 1.2 mL) to each knee (80 drops total dose), the following diclofenac pharmacokinetic parameters were obtained: (see Table 3 ). Table 3: Single-Dose (80 drops) and Multiple Dose (80 drops four times daily for 7 days) Diclofenac Sodium Topical Solution Pharmacokinetic Parameters Diclofenac Sodium Pharmacokinetic Parameters Normal Adults [N=18] (Age: 18 to 55 years) Normal Adults [N=19] (Age: 18 to 55 years) Single Dose Multiple Dose Four times daily for 7 days AUC 0-t 177.5 ± 72.6 ng∙h/mL 695.4 ± 348.9 ng∙h/mL AUC 0-inf 196.3 ± 68.5 ng∙h/mL 745.2 ± 374.7 ng∙h/mL Plasma C max 8.1 ± 5.9 ng/mL 19.4 ± 9.3 ng/mL Plasma T max (h) 11.0 ± 6.4 4.0 ± 6.5 Plasma t 1/2 (h) 36.7 ± 20.8 79.0 ± 38.1 Kel (h -1 ) 0.024 ± 0.010 0.011 ± 0.004 CL/F (L/h) 244.7 ± 84.7 Apparent total body clearance – Absorption Diclofenac systemic exposure from diclofenac sodium topical solution application (4 times daily for 1 week) was approximately 1/3 of the diclofenac systemic exposure from the diclofenac topical gel application (twice daily for 4 weeks). Distribution Diclofenac is more than 99% bound to human serum proteins, primarily to albumin. Diclofenac diffuses into and out of the synovial fluid. Diffusion into the joint occurs when plasma levels are higher than those in the synovial fluid, after which the process reverses and synovial fluid levels are higher than plasma levels. It is not known whether diffusion into the joint plays a role in the effectiveness of diclofenac. Elimination Metabolism Five diclofenac metabolites have been identified in human plasma and urine. The metabolites include 4'hydroxy-, 5-hydroxy-, 3'-hydroxy-, 4',5-dihydroxy- and 3'-hydroxy-4'-methoxy diclofenac. The major diclofenac metabolite, 4'-hydroxy-diclofenac, has very weak pharmacologic activity. The formation of 4'-hydroxy diclofenac is primarily mediated by CPY2C9. Both diclofenac and its oxidative metabolites undergo glucuronidation or sulfation followed by biliary excretion. Acylglucuronidation mediated by UGT2B7 and oxidation mediated by CPY2C8 may also play a role in diclofenac metabolism. CYP3A4 is responsible for the formation of minor metabolites, 5-hydroxy and 3'-hydroxy-diclofenac. Excretion Diclofenac is eliminated through metabolism and subsequent urinary and biliary excretion of the glucuronide and the sulfate conjugates of the metabolites. Little or no free unchanged diclofenac is excreted in the urine. Special Populations Pediatric: The pharmacokinetics of diclofenac sodium topical solution has not been investigated in pediatric patients. Race: Pharmacokinetic differences due to race have not been studied. Drug Interaction Studies Aspirin: When NSAIDs were administered with aspirin, the protein binding of NSAIDs were reduced, although the clearance of free NSAID was not altered. The clinical significance of this interaction is not known. See Table 1 for clinically significant drug interactions of NSAIDs with aspirin [ see Drug Interactions (7) ].