Overview
11 DESCRIPTION Diclofenac sodium topical solution USP, 2% w/w, contains diclofenac sodium, USP a benzeneacetic acid derivative that is a nonsteroidal anti-inflammatory drug, and is available as a clear, colorless to faintly pink or orange solution for topical application. The chemical name is 2 [(2,6-dichlorophenyl) amino]-benzeneacetic acid, monosodium salt. The molecular weight is 318.14.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 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.
Indications
- 1 INDICATIONS AND USAGE Diclofenac sodium topical solution is indicated for the treatment of the pain of osteoarthritis of the knee(s). Diclofenac sodium topical solution is a nonsteroidal anti-inflammatory drug indicated for the treatment of the pain of osteoarthritis of the knee(s). ( 1 )
Common Doses
- 40 mg
Dosage
2 DOSAGE AND ADMINISTRATION Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals. The recommended dose is 2 pump actuations on each painful knee, 2 times a day. ( 2 ) Apply diclofenac sodium topical solution, to clean, dry skin. ( 2.1 ) Dispense 40 mg (2 pump actuations) directly onto the knee or first into the hand and then onto the knee. Spread evenly around front, back and sides of the knee. ( 2.1 ) Wash hands completely after administering the product. ( 2.
Black Box Warning
WARNING: RISK OF SERIOUS CARDIOVASCULAR AND GASTROINTESTINAL EVENTS Cardiovascular Thrombotic Events Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular 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. [ see Warnings and Precautions ( 5.1 ) ]. Diclofenac sodium topical solution is contraindicated in the setting of coronary artery bypass graft (CABG) surgery [ see Contraindications ( 4 ) and Warnings and Precautions ( 5.1 ) ].
Contraindications
- 4 CONTRAINDICATIONS 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.
Side Effects
- 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.
Interactions
- 7 DRUG INTERACTIONS 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.