5.1 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 [ see Contraindications (4)and Warnings and Precautions (5.2)].

Seek emergency help if an anaphylactic reaction occurs.

5.2 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 topical gel is contraindicated in patients with this form of aspirin sensitivity. When diclofenac sodium topical gel is used in patients with preexisting asthma (without known aspirin sensitivity), monitor patients for changes in the signs and symptoms of asthma.

5.3 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. These serious events may occur without warning. Inform patients about the signs and symptoms of serious skin reactions, and to discontinue the use of diclofenac sodium topical gel at the first appearance of skin rash or any other sign of hypersensitivity. Diclofenac sodium topical gel is contraindicated in patients with previous serious skin reactions to NSAIDs. Do not apply diclofenac sodium topical gel to open skin wounds, infections, or exfoliative dermatitis, as it may affect absorption and tolerability of the drug [ see Contraindications (4)].

5.4 Cardiovascular 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 NSAID-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.

5.5 Gastrointestinal Bleeding, Ulceration, and Perforation

NSAIDs, including diclofenac, cause serious 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.

5.6 Hepatotoxicity

In clinical trials with diclofenac sodium topical gel, 2 to 3% of subjects had elevations of liver function tests (LFTs) [see Clinical Trials Experience (6.1)]. To minimize the potential risk for an adverse liver-related event in patients treated with diclofenac sodium topical gel, use the lowest effective dose for the shortest duration possible. Exercise caution when prescribing diclofenac sodium topical gel with concomitant drugs that are known to be potentially hepatotoxic (e.g., acetaminophen, antibiotics, anti-epileptics).

Physicians should measure transaminases at baseline and periodically in patients receiving long-term therapy with diclofenac, because severe hepatotoxicity may develop without a prodrome of distinguishing symptoms. The optimum times for making the first and subsequent transaminase measurements are not known. Based on clinical trial data and postmarketing experiences, transaminases should be monitored within 4 to 8 weeks after initiating treatment with diclofenac. However, severe hepatic reactions can occur at any time during treatment with diclofenac.

If abnormal liver tests persist or worsen, if clinical signs and/or symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, abdominal pain, diarrhea, dark urine, etc.), diclofenac sodium topical should be discontinued immediately.

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). If clinical signs and symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, etc.), discontinue diclofenac sodium topical gel immediately, and perform a clinical evaluation of the patient.

5.7 Hypertension

NSAIDs, including diclofenac sodium topical gel, can lead to new onset of hypertension or worsening of pre-existing hypertension, either of which may contribute to the increased incidence of CV events. Patients taking angiotensin converting enzyme (ACE) inhibitors, thiazide diuretics, or loop diuretics may have impaired response to these therapies when taking NSAIDs [see Drug Interactions (7)].

Monitor blood pressure (BP) during the initiation of NSAID treatment and throughout the course of therapy.

5.8 Heart Failure and Edema

The Coxib and traditional NSAID Trialists' Collaboration meta-analysis of randomized controlled trials demonstrated an approximately two-fold increase in hospitalizations for heart failure in COX-2 selective-treated patients and nonselective NSAID-treated patients compared to placebo-treated patients. In a Danish National Registry study of patients with heart failure, NSAID use increased the risk of MI, hospitalization for heart failure, and death.

Additionally, fluid retention and edema have been observed in some patients treated with NSAIDs. Use of diclofenac may blunt the CV effects of several therapeutic agents used to treat these medical conditions [e.g., diuretics, ACE inhibitors, or angiotensin receptor blockers (ARBs)].

Avoid the use of diclofenac sodium topical gel in patients with severe heart failure unless the benefits are expected to outweigh the risk of worsening heart failure. If diclofenac sodium topical gel is used in patients with severe heart failure, monitor patients for signs of worsening heart failure.

5.9 Renal Toxicity and Hyperkalemia

5.10 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) has been reported in patients taking NSAIDs such as diclofenac sodium topical gel. Some of these events have been fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling. Other clinical manifestations may include hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis. Sometimes symptoms of DRESS may resemble an acute viral infection. Eosinophilia is often present. Because this disorder is variable in its presentation, other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, discontinue diclofenac sodium topical gel and evaluate the patient immediately.

5.11 Fetal Toxicity

5.12 Hematologic Toxicity

Anemia has occurred in NSAID-treated patients. This may be due to occult or gross blood loss, fluid retention, or an incompletely described effect on erythropoiesis. If a patient treated with diclofenac sodium topical gel has any signs or symptoms of anemia, monitor hemoglobin or hematocrit.

NSAIDs, including diclofenac sodium topical gel, 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) and serotonin norepinephrine reuptake inhibitors (SNRIs) may increase this risk. Monitor these patients for signs of bleeding [see Drug Interactions (7)].

5.13 Masking of Inflammation and Fever

The pharmacological activity of diclofenac sodium topical gel in reducing inflammation, and possibly fever, may diminish the utility of diagnostic signs in detecting infections.

5.14 Laboratory Monitoring

Because serious GI bleeding, hepatotoxicity, and renal injury can occur without warning symptoms or signs, consider monitoring patients on long-term NSAID treatment with a CBC and a chemistry profile periodically [see Warnings and Precautions (5.5, 5.6, 5.9)] .

5.15 Photosensitivity

Patients should minimize or avoid exposure to natural or artificial sunlight (tanning beds or UVA/B treatment) while using diclofenac sodium topical gel. If patients need to be outdoors while using diclofenac sodium topical gel, they should wear loose-fitting clothes that protect skin from sun exposure and discuss other sun protection measures with their physician. Advise patients to discontinue treatment with diclofenac sodium topical gel at the first evidence of sunburn.

5.16 Exposure to Eyes and Mucosal Membranes

Avoid contact of diclofenac sodium topical gel with eyes and mucosa. Advise patients that if contact in the eye, or mucosal membranes occurs, immediately wash out the eye or mucosal membranes with water or saline and consult a physician if irritation persists for more than an hour.

5.17 Oral Nonsteroidal Anti-inflammatory Drugs

Concomitant use of oral and topical NSAIDs may result in a higher rate of hemorrhage, more frequent abnormal creatinine, urea and hemoglobin. Do not use diclofenac sodium topical gel in combination with an oral NSAID unless the benefit outweighs the risk and periodic laboratory evaluations are conducted.

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.

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 forOralDiclofenac 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.

8.1 Pregnancy

8.2 Lactation

8.3 Females and Males of Reproductive Potential

8.4 Pediatric Use

Actinic keratoses is not a condition seen within the pediatric population. Diclofenac sodium topical gel should not be used by children.

8.5 Geriatric Use

Elderly patients, compared to younger patients, are at greater risk for NSAID-associated serious cardiovascular, gastrointestinal, and/or renal adverse reactions. If the anticipated benefit for the elderly patient outweighs these potential risks, start dosing at the low end of the dosing range, and monitor patients for adverse effects [see Warnings and Precautions (5.4, 5.5, 5.6, 5.9, 5.14)].

Of the 211 subjects treated with diclofenac sodium topical gel in controlled clinical trials, 143 subjects were 65 years of age and over. Of those 143 subjects, 55 subjects were 75 years of age and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

12.1 Mechanism of Action

The mechanism of action of diclofenac sodium in the treatment of actinic keratoses (AK) is unknown.

12.2 Pharmacodynamics

The pharmacodynamics of diclofenac sodium topical gel in the treatment of actinic keratosis has not been assessed.

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

There did not appear to be any increase in drug-related neoplasms following daily topical applications of diclofenac sodium topical gel for 2 years at concentrations up to 0.035% diclofenac sodium and 2.5% hyaluronate sodium in albino mice.

When administered orally for 2 years, diclofenac showed no evidence of carcinogenic potential in rats given diclofenac sodium at up to 2 mg/kg/day (3 times the MRHD based on BSA comparison), or in mice given diclofenac sodium at up to 0.3 mg/kg/day in males and 1 mg/kg/day in females (25% and 83%, respectively, of the MRHD based on BSA comparison).

Diclofenac was not genotoxic in in vitropoint mutation assays in mammalian mouse lymphoma cells and Ames microbial test systems, or when tested in mammalian in vivoassays including dominant lethal and male germinal epithelial chromosomal studies in mice, and nucleus anomaly and chromosomal aberration studies in Chinese hamsters. It was also negative in the transformation assay utilizing BALB/3T3 mouse embryo cells.

Fertility studies have not been conducted with diclofenac sodium topical gel. Diclofenac sodium showed no evidence of impairment of fertility after oral treatment with 4 mg/kg/day (7 times the MRHD based on BSA comparison) in male or female rats.

Storage: Store at 20° to 25°C (68° to 77°F)[see USP Controlled Room Temperature]. Protect from heat. Avoid freezing.

Special Application Instructions

• Instruct patients not to apply diclofenac sodium topical gel to damaged skin resulting from any etiology, e.g., exudative dermatitis, eczema, infected lesion, burns or wounds.
• Instruct patients to minimize or avoid exposure to natural or artificial sunlight (tanning beds or UVA/B treatment) while using diclofenac sodium topical gel. If patients need to be outdoors while using diclofenac sodium topical gel, they should wear loose-fitting clothes that protect skin from sun exposure and discuss other sun protection measures with their physician. Advise patients to discontinue treatment with diclofenac sodium topical gel at the first evidence of sunburn.

Anaphylactic Reactions

Inform patients of the signs of an anaphylactic reaction (e.g., difficulty breathing, swelling of the face or throat). Instruct patients to seek immediate emergency help if these occur [see Contraindications (4)and Warnings and Precautions (5.1)].

Exacerbation of Asthma Related to Aspirin Sensitivity

Inform patients with aspirin sensitive asthma not to use diclofenac sodium topical gel. Advise patients with preexisting asthma to report any changes in the signs and symptoms of asthma to their healthcare provider [see Contraindications (4)and Warnings and Precautions (5.2)].

Serious Skin Reactions including DRESS

Advise patients to stop using diclofenac sodium topical gel immediately if they develop any type of rash or fever and to contact their healthcare provider as soon as possible [see Warnings and Precautions (5.3, 5.10)].

Cardiovascular Thrombotic Events

Advise patients to be alert for the symptoms of cardiovascular thrombotic events, including chest pain, shortness of breath, weakness, or slurring of speech, and to report any of these symptoms to their health care provider immediately [see Warnings and Precautions (5.4)].

Gastrointestinal Bleeding, Ulceration, and Perforation

Advise patients to report symptoms of ulcerations and bleeding, including epigastric pain, dyspepsia, melena, and hematemesis to their health care provider. In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, inform patients of the increased risk for and the signs and symptoms of GI bleeding [see Warnings and Precautions (5.5)].

Hepatotoxicity

Inform patients of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, pruritus, diarrhea, jaundice, right upper quadrant tenderness, and "flu-like" symptoms). Inform the patient that diclofenac sodium topical gel may increase the risk of elevated liver enzymes. Advise the patient that laboratory evaluation is needed prior to and periodically during treatment. Advise the patient that if signs or symptoms of liver injury occur, discontinue diclofenac sodium topical gel and seek medical advice promptly [see Warnings and Precautions (5.6)].

Heart Failure and Edema

Advise patients to be alert for the symptoms of congestive heart failure including shortness of breath, unexplained weight gain, or edema and to contact their healthcare provider if such symptoms occur [see Warnings and Precautions (5.8)].

Female Fertility

Advise females of reproductive potential who desire pregnancy that NSAIDs, including diclofenac sodium topical gel, may be associated with reversible delay in ovulation [see Use in Specific Populations (8.3)].

Fetal Toxicity

Inform pregnant women to avoid use of diclofenac sodium topical gel and other NSAIDs starting at 30 weeks gestation because of the risk of the premature closing of the fetal ductus arteriosus. If treatment with diclofenac sodium topical gel is needed for a pregnant woman between about 20 to 30 weeks gestation, advise her that she may need to be monitored for oligohydramnios, if treatment continues for longer than 48 hours [see Warnings and Precautions (5.11)and Use in Specific Populations (8.1)].

Avoid Concomitant Use of NSAIDs

Inform patients that the concomitant use of diclofenac sodium topical gel with other NSAIDs or salicylates (e.g., diflunisal, salsalate) is not recommended due to the increased risk of gastrointestinal toxicity [see Warnings and Precautions (5.5)and Drug Interactions (7)]. Alert patients that NSAIDs may be present in "over-the-counter" medications for treatment of colds, fever, or insomnia.

Use of NSAIDS and Low-Dose Aspirin

Inform patients not to use low-dose aspirin concomitantly with diclofenac sodium topical gel until they talk to their healthcare provider [see Drug Interactions (7)].

Exposure to Eyes and Mucosal Membranes

Instruct patients to avoid contact of diclofenac sodium topical gel with the eyes and mucosal membranes. Advise patients that if eye or mucosal membrane contact occurs, immediately wash out with water or saline and consult a physician if irritation persists for more than an hour [see Warnings and Precautions (5.16)].