Diclofenac Sodium 1.5% Diclofenac Sodium Topical 16.05 mg/mL Solution

5 WARNINGS AND PERCAUTIONS

5.1Cardiovascular Thrombotic Events Clinical trials of several 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 NASAID-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 diclofenac, 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 [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 diclofenac sodium in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If diclofenac sodium is used in patients with a recent MI, monitor patients for signs of cardiac ischemia.

5.2Gastrointestinal Bleeding, Ulceration, and Perforation NSAIDs, including diclofenac, 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-fold increased risk for developing a GI bleed compared to patients without these risk factors.

Other factors that increase the risk o…

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)]

6.1Clinical 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 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 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 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, 1.5% w/w in placebo and oral diclofenac-controlled trials. † Preferred Term according to COSTART

6.2Postmarketing Experience In non-U.S. postmarketing surveillance, the following adverse reactions have…

7 DRUG INTERACTIONS 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 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 (5.11)] 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 NSAID alone [see WARNINGS AND PRECAUTIONS (5.2)] Intervention Concomitant use of diclofenac sodium and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding [see WARNINGS AND PRECAUTIONS (5.11)]. Diclofenac sodium 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 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 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 diclofenac sodium 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 diclofenac with digoxin has been reported to increase the serum concentration and prolong the half-life digoxin. Intervention: During concomitant use of diclofenac sodium 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 prostagl…