Diclofenac Sodium, Methyl Salicylate

1. ​INDICATIONS & USAGE Xiclofen TM Ointment is indicated in adults over the age of 12 years old for the treatment of signs and symptoms of osteoarthritis of the joints, and of acute and chronic pain in muscles and joints associated with muscle soreness, strains, sprains, arthritis, simple backache, muscle stiffness, and more.

2. DOSAGE & ADMINISTRATION 2.1 General Dosing Instructions Use Xiclofen TM Ointment only on dry, intact (unbroken) skin. Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals. Avoid contact with eyes and mucous membranes. Avoid showering or bathing for at least 1 hour after application of Xiclofen TM Ointment. Avoid concomitant use of Xiclofen TM Ointment on the treated skin site with other external products, including sunscreens, cosmetics, lotions, moisturizers, insect repellants, or other external medications. Do not use combination therapy with diclofenac sodium and an oral NSAID unless the benefit outweighs the risk and conduct periodic assessments. 2.2 Dosing and Instructions for Use Apply product directly to the skin, up to 4 times daily (8.5g per day). Clothing may be worn over the area of application. Wash hands with soap and water after handling Xiclofen TM Ointment. If irritation or a burning sensation occurs during application, stop use and advise your doctor. When Xiclofen TM Ointment is used concomitantly with other products containing non-steroidal anti-inflammatory agents, the amount absorbed from all formulations must be considered.

5. WARNINGS, PRECAUTIONS & ADVERSE REACTIONS 5.1 Risk of Serious Cardiovascular and Gastrointestinal Events Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause an increased risk of serious cardiovascular (CV) thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. NSAIDs, including diclofenac, can lead to new onset of hypertension, or worsening of preexisting hypertension, either of which may contribute to the increased incidence of CV events. To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Avoid the use of diclofenac sodium external in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If diclofenac sodium external is used in patients with a recent MI, monitor patients for signs of cardiac ischemia. Avoid using NSAIDs within 14 days following coronary artery bypass graft (CABG) surgery. 5.2 Gastrointestinal Bleeding, Ulceration, and Perforation Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause an increased risk of serious gastrointestinal (GI) adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events can occur at any time during use and without warning symptoms. Other factors that increase the risk of GI bleeding in patients treated with NSAIDs include concomitant use of oral corticosteroids, aspirin, anticoagulants, or selective serotonin reuptake inhibitors (SSRIs). Elderly patients and patients with a prior history of peptic ulcer disease and/or GI bleeding are at greater risk for serious GI events. Additionally, patients with advanced liver disease and/or coagulopathy are at increased risk for GI bleeding. 5.3 Hepatotoxicity In postmarketing reports, cases of drug-induced hepatotoxicity have been reported in the first month, and in some cases, the first 2 months of therapy, but can occur at any time during treatment with diclofenac. Postmarketing surveillance has reported cases of severe hepatic reactions, including liver necrosis, jaundice, fulminant hepatitis, with and without jaundice, and liver failure. Some of these reported cases resulted in fatalities or liver transplantation. Monitor for 4 to 8 weeks after initiating treatment with diclofenac. However, severe hepatic reactions can occur at any time during treatment with diclofenac. Inform patients of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, diarrhea, pruritus, jaundice, right upper quadrant tenderness, and “flu-like” symptoms). To minimize potential risk for an adverse liver-related event in patients treated with diclofenac sodium external, exercise caution when prescribing diclofenac external with concomitant drugs that are known to be potentially hepatotoxic (e.g., acetaminophen, antibiotics, antiepileptics). 5.4 Renal Toxicity and Hyperkalemia Renal Toxicity Long-term administration of NSAIDs has resulted in renal papillary necrosis and other renal injury. Renal toxicity has also been seen in patients in whom renal prostaglandins have a compensatory role in the maintenance of renal perfusion. In these patients, administration of an NSAID may cause a dose-dependent reduction in prostaglandin formation and, secondarily, in renal blood flow, which may precipitate overt renal decompensation. Patients at greatest risk of this reaction are those with impaired renal function, dehydration, hypovolemia, heart failure, liver dysfunction, those taking diuretics and ACE inhibitors or ARBs, and the elderly. Discontinuation of NSAID therapy was usually followed by recovery to the pretreatment state. Avoid the use of diclofenac sodium external in patients with advanced renal disease unless the benefits are expected to outweigh the risk of worsening renal function. If diclofenac sodium is used in patients with advanced renal disease, monitor patients for signs of worsening symptoms. Hyperkalemia Increases in serum potassium concentration, including hyperkalemia, have been reported with use of NSAIDs, even in some patients without renal impairment. In patients with normal renal function, these effects have been attributed to a hyporeninemic-hypoaldosteronism state. 5.5 Anaphylactic Reactions Diclofenac has been associated with anaphylactic reactions in patients with and without known hypersensitivity to diclofenac and in patients with aspirin-sensitive asthma. Seek emergency help if an anaphylactic reaction occurs. 5.6 Exacerbation of Asthma Related to Aspirin Sensitivity A subpopulation of patients with asthma may have aspirin-sensitive asthma which may include chronic rhinosinusitis complicated by nasal polyps; severe, potentially fatal bronchospasm; and/or intolerance to aspirin and other NSAIDs. Because cross-reactivity between aspirin and other NSAIDs has been reported in such aspirin-sensitive patients, diclofenac sodium external is contraindicated in patients with this form of aspirin sensitivity. When diclofenac is used in patients with preexisting asthma, monitor patients for changes in the signs and symptoms. 5.7 Serious Skin Reactions NSAIDs, including diclofenac, can cause serious skin adverse reactions such as exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. Inform patients about the signs and symptoms of serious skin reactions, and to discontinue the use of diclofenac sodium external at the first appearance of any skin hypersensitivity. 5.8 Hematologic Toxicity Anemia has occurred in NSAID-treated patients. If a patient treated with diclofenac sodium external has any signs or symptoms of anemia, monitor hemoglobin or hematocrit. NSAIDs, including diclofenac, may increase the risk of bleeding events. Co-morbid conditions such as coagulation disorders, concomitant use of warfarin, other anticoagulants, antiplatelet agents (e.g., aspirin), serotonin reuptake inhibitors (SSRIs) may increase this risk. 5.9 Masking of Inflmmation and Fever The pharmacological activity of diclofenac in reducing inflammation, and possibly fever, may diminish the utility of diagnostic signs in detecting infections. 5.10 Sun Exposure Instruct patients to avoid exposure to natural or artificial sunlight after treatment of Xiclofen TM Ointment because studies in animals indicated external diclofenac treatment resulted in an earlier onset of ultraviolet light-induced skin tumors. The potential effects of diclofenac sodium external on skin response to ultraviolet damage in humans are not known. 5.11 Excessive Dosing Excessive dosing by applying larger amounts of Xiclofen TM Ointment could result in increased absorption of diclofenac sodium and methyl salicylate and high blood concentrations. Longer duration of application, application of more than the recommended dosage, smaller patients, or impaired elimination may all contribute to increasing the blood concentration of diclofenac sodium and methyl salicylate. 5.12 Application-Associated Pain During or immediately after treatment with Xiclofen TM Ointment, the skin at the site of application may develop blisters, bruising, burning sensation, depigmentation, dermatitis, discoloration, edema, erythema, exfoliation, irritation, papules, petechia, pruritus, vesicles, or may be the locus of abnormal sensation. These reactions are generally mild and transient, resolving spontaneously within a few minutes to hours. 5.13 Increase in Blood Pressure Patient with unstable or poorly controlled hypertension, or a recent history of cardiovascular or cerebrovascular events, may be at increased risk of adverse cardiovascular effects. Consider these factors prior to initiating Xiclofen TM Ointment treatment. Monitor blood pressure periodically during and following the treatment procedure and provide adequate support for treatment-relate

4. CONTRAINDICATIONS Xiclofen TM Ointment is contraindicated in patients with a known history of hypersensitivity to non-steroidal anti-inflammatory medications such as diclofenac sodium or methyl salicylate. History of asthma, urticaria, or allergic-type reactions after absorbing nonsteroidal anti-inflammatory drugs (NSAIDs) should also be considered.

6. DRUG INTERACTIONS Drugs That Interfere with Hemostasis Monitor patients with concomitant use of diclofenac sodium external 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. Aspirin Concomitant use of diclofenac sodium external and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding. ACE Inhibitors, Angiotensin Receptor Blockers, and Beta-Blockers When these drugs are administered concomitantly, patients should be adequately hydrated. Assess renal function at the beginning of the concomitant treatment. Diuretics During concomitant use of diclofenac sodium external with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects. Digoxin During concomitant use of diclofenac sodium external and digoxin, monitor serum digoxin levels. Lithium During concomitant use of diclofenac sodium external and lithium, monitor patients for signs of lithium toxicity. Methotrexate During concomitant use of diclofenac sodium external and methotrexate, monitor patients for methotrexate toxicity. Cyclosporine During concomitant use of diclofenac sodium external and cyclosporine, monitor patients for signs of worsening renal function. Pemetrexed Concomitant use of diclofenac sodium external and pemetrexed may increase the risk of pemetrexed-associated myelosuppression, renal, and GI toxicity.

10. CLINICAL PHARMACOLOGY 10.1 Mechanism of Action Diclofenac has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of diclofenac, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2). Diclofenac is a potent inhibitor of prostaglandin synthesis in vitro. Diclofenac concentrations reached during therapy have produced in vivo effects. Prostaglandins sensitive afferent nerves and potentiate the action of bradykinin in inducing pain in animal models. Prostaglandins are mediators of inflammation. Because diclofenac is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. 10.2 Pharmacokinetics 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. 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. Diclofenac is eliminated through metabolism and subsequent urinary and biliary excretion of the glucuronide and the sulfate conjugates of the metabolites.