DICLOFENAC SODIUM

Diclofenac sodium topical gel, 3%, intended for dermatologic use, contains the active ingredient, diclofenac sodium, in a clear, transparent, colorless to slightly yellow or orange gel base. Diclofenac sodium is a white or slightly yellowish hygroscopic crystalline powder. It is freely soluble in methanol, soluble in ethanol, sparingly soluble in water, slightly soluble in acetone, and partially insoluble in ether. The chemical name for diclofenac sodium is: Sodium [ o- (2,6-dichloranilino) phenyl] acetate Diclofenac sodium has a molecular weight of 318.13. The CAS number is CAS-15307-79-6. The structural formula is represented below: Diclofenac sodium topical gel, 3% also contains benzyl alcohol, sodium hyaluronate, polyethylene glycol monomethyl ether, and purified water. 1 g of diclofenac sodium topical gel, 3% contains 30 mg of the active substance, diclofenac sodium. Image

Diclofenac sodium topical gel is a nonsteroidal anti-inflammatory drug (NSAID) indicated for the topical treatment of actinic keratoses (AK). ( 1 ) Diclofenac sodium topical gel is indicated for the topical treatment of actinic keratoses (AK).

Use the lowest effective dosage for shortest duration consistent with the individual patient treatment goals. ( 2 ) Apply to lesion areas twice daily to adequately cover each lesion. ( 2 ) Use 0.5 g of gel (pea size) on each 5 cm x 5 cm lesion site. ( 2 ) The recommended duration of therapy is from 60 days to 90 days. Complete healing of the lesion(s) or optimal therapeutic effect may not be evident for up to 30 days following cessation of therapy. Lesions that do not respond to therapy should be re-evaluated and management reconsidered. ( 2 ) Avoid contact in eyes, nose, or mouth. ( 2 ) Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals [see Warnings and Precautions ( 5 )] . Apply diclofenac sodium topical gel gently to lesion areas twice daily to adequately cover each lesion. Use 0.5 g of gel (pea size) on each 5 cm x 5 cm lesion site. The recommended duration of therapy is from 60 days to 90 days. Complete healing of the lesion(s) or optimal therapeutic effect may not be evident for up to 30 days following cessation of therapy. Lesions that do not respond to therapy should be re-evaluated and management reconsidered. Avoid contact of diclofenac sodium topical gel with eyes and mucous membranes.

Known hypersensitivity to diclofenac or any components of the drug product. ( 4 , 11 ) History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs. ( 4 ) Use on damaged skin. ( 4 ) In the setting of coronary artery bypass graft (CABG) surgery. ( 4 ) Diclofenac sodium topical gel is contraindicated in the following patients: With known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to diclofenac or any components of the drug product [see Warnings and Precautions ( 5.1 , 5.3 , 5.10 ) and Description ( 11 )] With the 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 ( 5.1 , 5.2 )] Application on damaged skin resulting from any etiology, including exudative dermatitis, eczema, infected lesions, burns or wounds [see Warnings and Precautions ( 5.3 )] In the setting of coronary bypass graft (CABG) surgery [see Warnings and Precautions ( 5.4 )]

The following adverse reactions are discussed in greater detail in other sections of the labeling: Anaphylactic Reactions [ see Warnings and Precautions ( 5.1 )] Exacerbation of Asthma Related to Aspirin Sensitivity [ see Warnings and Precautions ( 5.2 )] Serious Skin Reactions [ see Warnings and Precautions ( 5.3 )] Cardiovascular Thrombotic Events [ see Warnings and Precautions ( 5.4 )] GI Bleeding, Ulceration and Perforation [ see Warnings and Precautions ( 5.5 )] Hepatotoxicity [ see Warnings and Precautions ( 5.6 )] Hypertension [ see Warnings and Precautions ( 5.7 )] Heart Failure and Edema [ see Warnings and Precautions ( 5.8 )] Renal Toxicity and Hyperkalemia [ see Warnings and Precautions ( 5.9 )] DRESS [ see Warnings and Precautions ( 5.10 )] Hematologic Toxicity [ see Warnings and Precautions ( 5.12 )] Photosensitivity [ see Warnings and Precautions ( 5.15 )] Most common adverse reactions with diclofenac sodium topical gel are application site reactions, including dermatitis. ( 6) To report SUSPECTED ADVERSE REACTIONS, contact Alembic Pharmaceuticals, Inc. at 1-866-210-9797 or FDA at 1-800-FDA-1088 or www.fda.gov/med.watch. 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. Of the 423 subjects evaluable for safety in adequate and well-controlled trials, 211 were treated with diclofenac sodium topical gel drug product and 212 were treated with a vehicle gel. Eighty-seven percent (87%) of the diclofenac sodium topical gel-treated subjects (183 subjects) and 84% of the vehicle-treated subjects (178 subjects) experienced one or more adverse events (AEs) during the trials. The majority of these reactions were mild to moderate in severity and resolved upon discontinuation of therapy. Of the 211 subjects treated with diclofenac sodium topical gel, 172 (82%) experienced AEs involving skin and the application site compared to 160 (75%) vehicle-treated subjects. Application site reactions (ASRs) were the most frequent AEs in both diclofenac sodium topical gel- and vehicle-treated groups. Of note, four reactions, contact dermatitis, rash, dry skin and exfoliation (scaling) were significantly more prevalent in the diclofenac sodium topical gel group than in the vehicle-treated subjects. Eighteen percent of diclofenac sodium topical gel-treated subjects and 4% of vehicle-treated subjects discontinued from the clinical trials due to adverse events (whether considered related to treatment or not). These discontinuations were mainly due to skin irritation or related cutaneous adverse reactions. Table 1 below presents the AEs reported at an incidence of >1% for subjects treated with either diclofenac sodium topical gel or vehicle (60- and 90-day treatment groups) during the phase 3 trials. Table 1. Adverse Events Reported (>1% in Any Treatment Group) During Diclofenac sodium topical gel Phase 3 Clinical Trials Incidences for 60-Day and 90-Day Treatments 60-day Treatment 90-day Treatment Diclofenac sodium topical gel (%) Gel Vehicle (%) Diclofenac sodium topical gel (%) Gel Vehicle (%) N=48 N=49 N=114 N=114 BODY AS A WHOLE 21 20 20 18 Abdominal Pain 2 0 1 0 Accidental Injury 0 0 4 2 Allergic Reaction 0 0 1 3 Asthenia 0 0 2 0 Back Pain 4 0 2 2 Chest Pain 2 0 1 0 Chills 0 2 0 0 Flu Syndrome 10 6 1 4 Headache 0 6 7 6 Infection 4 6 4 5 Neck Pain 0 0 2 0 Pain 2 0 2 2 CARDIOVASCULAR SYSTEM 2 4 3 1 Hypertension 2 0 1 0 Migraine 0 2 1 0 Phlebitis 0 2 0 0 DIGESTIVE SYSTEM 4 0 6 8 Constipation 0 0 0 2 Diarrhea 2 0 2 3 Dyspepsia 2 0 3 4 METABOLIC AND NUTRITIONAL DISORDERS 2 8 7 2 Creatine Phosphokinase Increased 0 0 4 1 Creatinine Increased 2 2 0 1 Edema 0 2 0 0 Hypercholesteremia 0 2 1 0 Hyperglycemia 0 2 1 0 SGOT Increased 0 0 3 0 SGPT Increased 0 0 2 0 MUSCULOSKELETAL SYSTEM 4 0 3 4 Arthralgia 2 0 0 2 Arthrosis 2 0 0 0 Myalgia 2 0 3 1 NERVOUS SYSTEM 2 2 2 5 Anxiety 0 2 0 1 Dizziness 0 0 0 4 Hypokinesia 2 0 0 0 RESPIRATORY SYSTEM 8 8 7 6 Asthma 2 0 0 0 Dyspnea 2 0 2 0 Pharyngitis 2 8 2 4 Pneumonia 2 0 0 1 Rhinitis 2 2 2 2 Sinusitis 0 0 2 0 SKIN AND APPENDAGES 75 86 86 71 Acne 0 2 0 1 Application Site Reaction 75 71 84 70 Acne 0 4 1 0 Alopecia 2 0 1 1 Contact Dermatitis 19 4 33 4 Dry Skin 27 12 25 17 Edema 4 0 3 0 Exfoliation 6 4 24 13 Hyperesthesia 0 0 3 1 Pain 15 22 26 30 Paresthesia 8 4 20 20 Photosensitivity Reaction 0 2 3 0 Pruritus 31 59 52 45 Rash 35 20 46 17 Vesiculobullous Rash 0 0 4 1 Contact Dermatitis 2 0 0 0 Dry Skin 0 4 3 0 Herpes Simplex 0 2 0 0 Maculopapular Rash 0 2 0 0 Pain 2 2 1 0 Pruritus 4 6 4 1 Rash 2 10 4 0 Skin Carcinoma 0 6 2 2 Skin Nodule 0 2 0 0 Skin Ulcer 2 0 1 0 SPECIAL SENSES 2 0 4 2 Conjunctivitis 2 0 4 1 Eye Pain 0 2 2 0 UROGENITAL SYSTEM 0 0 4 5 Hematuria 0 0 2 1 OTHER 0 0 0 3 Procedure 0 0 0 3 Skin and Appendages Adverse Events Reported for diclofenac sodium topical gel at Less Than 1% Incidence in the Phase 3 Studies: skin hypertrophy, paresthesia, seborrhea, urticaria, application site reactions (skin carcinoma, hypertonia, skin hypertrophy lacrimation disorder, maculopapular rash, purpuric rash, vasodilation). Adverse Reactions Reported for Oral Diclofenac Dosage Form (not topical diclofenac sodium gel): *Incidence Greater than 1% marked with asterisk. Body as a Whole: abdominal pain or cramps*, headache*, fluid retention*, abdominal distention*, malaise, swelling of lips and tongue, photosensitivity, anaphylaxis, anaphylactoid reactions, chest pain. Cardiovascular: hypertension, congestive heart failure, palpitations, flushing, tachycardia, premature ventricular contractions, myocardial infarction, hypotension. Digestive: diarrhea*, indigestion*, nausea*, constipation*, flatulence*, liver test abnormalities*, PUB*, i.e., peptic ulcer, with or without bleeding and/or perforation, or bleeding without ulcer, vomiting, jaundice, melena, esophageal lesions, aphthous stomatitis, dry mouth and mucous membranes, bloody diarrhea, hepatitis, hepatic necrosis, cirrhosis, hepatorenal syndrome, appetite change, pancreatitis with or without concomitant hepatitis, colitis, intestinal perforation. Hemic and Lymphatic: hemoglobin decrease, leukopenia, thrombocytopenia, eosinophilia, hemolytic anemia, aplastic anemia, agranulocytosis, purpura, allergic purpura, bruising. Metabolic and Nutritional Disorders: azotemia, hypoglycemia, weight loss. Nervous System: dizziness*, insomnia, drowsiness, depression, diplopia, anxiety, irritability, aseptic meningitis, convulsions, paresthesia, memory disturbance, nightmares, tremor, tic, abnormal coordination, disorientation, psychotic reaction. Respiratory: epistaxis, asthma, laryngeal edema, dyspnea, hyperventilation, edema of pharynx. Skin and Appendages: rash*, pruritus*, alopecia, urticaria, eczema, dermatitis, bullous eruption, erythema multiforme major, angioedema, Stevens-Johnson syndrome, excess perspiration, exfoliative dermatitis. Special Senses: tinnitus*, blurred vision, taste disorder, reversible and irreversible hearing loss, scotoma, vitreous floaters, night blindness, amblyopia. Urogenital: nephrotic syndrome, proteinuria, oliguria, interstitial nephritis, papillary necrosis, acute renal failure, urinary frequency, nocturia, hematuria, impotence, vaginal bleeding. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of diclofenac sodium topical gel and other topical diclofenac products. 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. Adverse reactions from diclofenac sodium topical gel: burning sensation, hypersensitivity. Adverse reactions from other topical diclofenac products: hypoesthesia, gait disturbance, musculoskeletal stiffness.

Drugs that Interfere with Hemostasis (e.g., warfarin, aspirin, SSRIs/SNRIs): Monitor patients for bleeding who are using diclofenac sodium topical gel concomitantly with drugs that interfere with hemostasis. ( 7 ) ACE Inhibitors, Angiotensin Receptor Blockers (ARB), or Beta-Blockers: Concomitant use with diclofenac sodium topical gel may diminish the antihypertensive effect of these drugs. ( 7 ) ACE Inhibitors and ARBs: Concomitant use with diclofenac sodium topical gel in elderly, volume depleted, or those with renal impairment may result in deterioration of renal function. ( 7 ) Diuretics: NSAIDs can reduce natriuretic effect of furosemide and thiazide diuretics. ( 7 ) Digoxin: Concomitant use with diclofenac sodium topical gel may increase serum concentration and prolong half-life of digoxin. ( 7 ) See Table 2 for clinically significant drug interactions with diclofenac. Table 2: Clinically Significant Drug Interactions with Diclofenac Drugs That Interfere with Hemostasis Clinical Impact: Diclofenac and anticoagulants such as warfarin have a synergistic effect on bleeding. The concomitant use of diclofenac 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 diclofenac sodium topical gel with anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin), selective serotonin reuptake inhibitors (SSRIs), and serotonin norepinephrine reuptake inhibitors (SNRIs) for signs of bleeding [see Warnings and Precautions ( 5.5 )] . Aspirin Clinical Impact: 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 ( 5.5 )] . Intervention: Concomitant use of diclofenac sodium topical gel and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding [see Warnings and Precautions ( 5.12 )] . Diclofenac sodium topical gel 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 angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (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 diclofenac sodium topical gel and ACE-inhibitors, ARBs, or beta-blockers, monitor blood pressure to ensure that the desired blood pressure is obtained. During concomitant use of diclofenac sodium topical gel 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 ( 5.9 )] . 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 diclofenac sodium topical gel with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects [see Warnings and Precautions ( 5.9 )] . Digoxin Clinical Impact: The concomitant use of diclofenac with digoxin has been reported to increase the serum concentration and prolong the half-life of digoxin. Intervention: During concomitant use of diclofenac sodium topical gel 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 diclofenac sodium topical gel 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). Intervention: During concomitant use of diclofenac sodium topical gel and methotrexate, monitor patients for methotrexate toxicity. Cyclosporine Clinical Impact: Concomitant use of diclofenac sodium topical gel and cyclosporine may increase cyclosporine's nephrotoxicity. Intervention: During concomitant use of diclofenac sodium topical gel and cyclosporine, monitor patients for signs of worsening renal function. NSAIDs and Salicylates Clinical Impact: Concomitant use of diclofenac sodium topical gel with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity [see Warnings and Precautions ( 5.5 )] . Intervention: The concomitant use of diclofenac sodium topical gel with other NSAIDs or salicylates is not recommended. Pemetrexed Clinical Impact: Concomitant use of diclofenac sodium topical gel and pemetrexed may increase the risk of pemetrexed-associated myelosuppression, renal, and GI toxicity (see the pemetrexed prescribing information). Intervention: During concomitant use of diclofenac sodium topical gel and pemetrexed, in patients with renal impairment whose creatinine clearance ranges from 45 to 79 mL/min, monitor for myelosuppression, renal and GI toxicity. NSAIDs with short elimination half-lives (e.g., diclofenac, indomethacin) should be avoided for a period of two days before, the day of, and two days following administration of pemetrexed. In the absence of data regarding potential interaction between pemetrexed and NSAIDs with longer half-lives (e.g., meloxicam, nabumetone), patients taking these NSAIDs should interrupt dosing for at least five days before, the day of, and two days following pemetrexed administration.