DICLOFENAC SODIUMDELAYED RELEASE DELAYED RELEASE- diclofenac sodium tablet, delayed release
Delayed-Release Tablets USP
Rx only Prescribing information
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].
- Diclofenac sodium delayed-release tablets are contraindicated in the setting of coronary artery bypass graft (CABG) surgery [see Contraindications and Warnings].
- NSAIDs cause an increased risk of serious gastrointestinal adverse events including inflammation, 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. Elderly patients are at greater risk for serious gastrointestinal events. [see Warnings].
Diclofenac, as the sodium salt, is a benzene-acetic acid derivative. The chemical name is 2-[(2,6-dichlorophenyl)amino] benzeneacetic acid, monosodium salt. The molecular weight is 318.14. Its molecular formula is C 14 H 10 Cl 2 NNaO 2 , and it has the following structural formula:
Each enteric-coated tablet for oral administration contains 25 mg, 50 mg or 75 mg of diclofenac sodium. In addition, each tablet contains the following inactive ingredients; black iron oxide, hypromellose, lactose monohydrate, magnesium stearate, methacrylic acid copolymer, microcrystalline cellulose, pharmaceutical glaze, polyethylene glycol, povidone, sodium starch glycolate, talc, titanium dioxide, triethyl citrate.
Diclofenac sodium delayed-release tablets is a nonsteroidal anti-inflammatory drug (NSAID) that exhibits anti-inflammatory, analgesic, and antipyretic activities in animal models. The mechanism of action of diclofenac, like that of other NSAIDs, is not completely understood but may be related to prostaglandin synthetase inhibition.
Diclofenac is 100% absorbed after oral administration compared to IV administration as measured by urine recovery. However, due to firstpass metabolism, only about 50% of the absorbed dose is systemically available (see Table 1). Food has no significant effect on the extent of diclofenac absorption. However, there is usually a delay in the onset of absorption of 1 to 4.5 hours and a reduction in peak plasma levels of <20%.
|PK Parameter||Normal Healthy Adults (20-48 yrs.)|
|Mean||Coefficient of mean Variation (%)|
|Absolute Bioavailability (%) [N =7]||55||40|
|T max (hr) [N = 56]||2.3||69|
|Oral Clearance (CL/F; mL/min) [N = 56]||582||23|
|Renal Clearance (% unchanged drug in urine) [N = 7]||<1||—|
|Apparent Volume of Distribution (V/F; L/kg) [N = 56]||1.4||58|
|Terminal Half-life (hr) [N = 56]||2.3||48|
The apparent volume of distribution (V/F) of diclofenac sodium is 1.4 L/kg.
Diclofenac is more than 99% bound to human serum proteins, primarily to albumin. Serum protein binding is constant over the concentration range (0.15 to 105 μg/mL) achieved with recommended doses.
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. The major diclofenac metabolite, 4′-hydroxy-diclofenac, has very weak pharmacologic activity. The formation of 4′-hydroxy- diclofenac is primarily mediated by CPY2C9. Both diclofenac and its oxidative metabolites undergo glucuronidation or sulfation followed by biliary excretion. Acylglucuronidation mediated by UGT2B7 and oxidation mediated by CPY2C8 may also play a role in diclofenac metabolism. CYP3A4 is responsible for the formation of minor metabolites, 5-hydroxyand 3′-hydroxy-diclofenac. In patients with renal dysfunction, peak concentrations of metabolites 4′-hydroxy- and 5-hydroxy-diclofenac were approximately 50% and 4% of the parent compound after single oral dosing compared to 27% and 1% in normal healthy subjects.
Diclofenac is eliminated through metabolism and subsequent urinary and biliary excretion of the glucuronide and the sulfate conjugates of the metabolites. Little or no free unchanged diclofenac is excreted in the urine. Approximately 65% of the dose is excreted in the urine and approximately 35% in the bile as conjugates of unchanged diclofenac plus metabolites. Because renal elimination is not a significant pathway of elimination for unchanged diclofenac, dosing adjustment in patients with mild to moderate renal dysfunction is not necessary. The terminal half-life of unchanged diclofenac is approximately 2 hours.
When co-administered with voriconazole (inhibitor of CYP2C9, 2C19 and 3A4 enzyme), the Cmax and AUC of diclofenac increased by 114% and 78%, respectively [see Precautions, Drug Interactions].
Pediatric: The pharmacokinetics of diclofenac has not been investigated in pediatric patients.
Race: Pharmacokinetic differences due to race have not been identified.
Hepatic Insufficiency : Hepatic metabolism accounts for almost 100% of diclofenac elimination, so patients with hepatic disease may require reduced doses of diclofenac compared to patients with normal hepatic function.
Renal Insufficiency : Diclofenac pharmacokinetics has been investigated in subjects with renal insufficiency. No differences in the pharmacokinetics of diclofenac have been detected in studies of patients with renal impairment. In patients with renal impairment (insulin clearance 60 to 90, 30 to 60, and <30 mL/min; N=6 in each group), AUC values and elimination rate were comparable to those in healthy subjects.
INDICATIONS & USAGE
Carefully consider the potential benefits and risks of diclofenac sodium delayed-release tablets and other treatment options before deciding to use diclofenac. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals [see Warnings].
Diclofenac is indicated:
- For relief of the signs and symptoms of osteoarthritis
- For relief of the signs and symptoms of rheumatoid arthritis
- For acute or long-term use in the relief of the signs and symptoms of ankylosing spondylitis.
Diclofenac sodium delayed-release tablets is contraindicated in patients with known hypersensitivity to diclofenac.
Diclofenac should not be given to patients who have experienced asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, rarely fatal, anaphylactic-like reactions to NSAIDs have been reported in such patients [see Warnings, Anaphylactic Reactions, and Precautions, Preexisting Asthma].
- In the setting of coronary artery bypass graft (CABG) surgery [see Warnings]
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