Diclofenac sodium topical solution is indicated for the treatment of the pain of osteoarthritis of the knee(s).
12.1 Mechanism of Action Diclofenac has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of diclofenac sodium topical solution, 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 sensitize 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. 12.3 Pharmacokinetics Absorption: After administration of diclofenac sodium topical solution topical solution (40 mg/knee every 12 h; total daily diclofenac exposure: 80 mg/knee) for 7.5 days, the mean (SD) AUC0-12 and mean (SD) Cmax were 77.27 (49.89) ng∙h/mL and 12.16 (7.66) ng/mL, respectively, on Day 1; and 204.58 (111.02) ng∙h/mL and 25.24 (12.95) ng/mL, respectively, at steady state on Day 8. After administration of diclofenac sodium topical solution 1.5% topical solution (19.3 mg/knee every 6 h; total daily diclofenac exposure 77.2 mg/knee), the mean (SD) AUC0-12 and mean (SD) Cmax were 27.46 (23.97) ng∙h/mL and 2.30 (2.02) ng/mL, respectively, on Day 1; and 141.49 (92.47) ng∙h/mL and 17.04 (11.28) ng/mL, respectively, at steady state on Day 8. The pharmacokinetics and effect of diclofenac sodium topical solution were not evaluated under the conditions of heat application, occlusive dressings overlay, or exercise following product application. Therefore, concurrent use of diclofenac sodium topical solution under these conditions is not recommended. 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…
Always consult a registered doctor before taking any medicine. This information is for general knowledge only.
2.1 General Dosing Instructions Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals [see Warnings and Precautions (5.2)]. For relief of the pain of osteoarthritis (OA) of the knee(s), the recommended dose is 40 mg of diclofenac sodium (2 pump actuations) on each painful knee, 2 times a day. Apply diclofenac sodium topical solution to clean, dry skin. The pump must be primed before first use. Instruct patients to fully depress the pump mechanism (actuation) 4 times while holding the bottle in an upright position. This portion should be discarded to ensure proper priming of the pump. No further priming of the bottle should be required. After the priming procedure, diclofenac sodium topical solution is properly dispensed by completely depressing the pump 2 times to achieve the prescribed dosage for one knee. Deliver the product directly into the palm of the hand and then apply evenly around front, back, and sides of the knee. 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 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 and 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…
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)] 6.1 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. Diclofenac Sodium Topical Solution The data described below reflect exposure to diclofenac sodium topical solution of 130 patients treated for 4 weeks (mean duration of 28 days) in one Phase 2 controlled trial. This population's mean age was approximately 60 years, 85% of patients were Caucasian, 65% 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 study. Application Site Reactions: In this controlled trial, application site reactions were characterized by one or more of the following: dryness (22%), exfoliation (7%), erythema (4%), pruritus (2%), pain (2%), induration (2%), rash (2%), and scabbing (<1%). Other Common Adverse Reactions: 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 vehicle, from a…
Diclofenac sodium topical solution is contraindicated in the following patients: • Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to diclofenac or any components of the drug product [see Warnings and Precautions (5.7, 5.9)] • 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 (5.7, 5.8)] • In the setting of coronary artery bypass graft (CABG) surgery [see Warnings and Precautions (5.1)]
See Table 3 for clinically significant drug interactions with diclofenac. Table 3: 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 increased the 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. 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 solution 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 (5.12)] 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 the NSAID alone [see Warnings and Precautions (5.2)] Intervention: Concomitant use of diclofenac sodium topical solution 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 solution is not a substitute for low dose…
5.1 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 [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 10-14 days following CABG surgery found an increased incidence of myocardial infarction and stroke. NSAIDs are contraindicated in the…