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Prescribing Information
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; Gastrointestinal Bleeding, Ulceration, and Perforation).
Status Post-Coronary Artery Bypass Graft (CABG) Surgery
Two large, controlled, clinical trials of 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. NSAIDs are contraindicated in the setting of CABG (
see
CONTRAINDICATIONS).
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 Extended-release Tablets in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If Diclofenac Sodium Extended-release Tablets are used in patients with a recent MI, monitor patients for signs of cardiac ischemia.
Gastrointestinal Bleeding, Ulceration, and Perforation
NSAIDs, including diclofenac, can 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 3-6 months, and in about 2%-4% of
patients treated for one year. However, even short-term 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 use 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 of GI bleeding in patients treated with NSAIDs include longer duration of NSAID therapy, concomitant use of oral corticosteroids, aspirin, anticoagulants, or selective serotonin reuptake inhibitors (SSRIs); smoking, use of alcohol, older age, and poor general health status. Most postmarketing reports of fatal GI events occurred in elderly or debilitated patients. Additionally, patients
with advanced liver disease and/or coagulopathy are at increased risk for GI bleeding.
Strategies to Minimize the GI Risks in NSAID-treated patients:
- • Use the lowest effective dose for the shortest possible duration.
- • Avoid administration of more than one NSAID at a time.
- • Avoid use in patients at higher risk unless benefits are expected to outweigh the increased risk of bleeding. For such patients, as well as those with active GI bleeding, consider alternate therapies other than NSAIDs.
- • Remain alert for signs and symptoms of GI ulceration and bleeding during NSAID therapy.
- • If a serious GI adverse event is suspected, promptly initiate evaluation and treatment, and discontinue Diclofenac Sodium Extended-release Tablets until a serious GI adverse event is ruled out.
- • In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, monitor patients more closely for evidence of GI bleeding (see PRECAUTIONS; Drug Interactions).
- 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.
- 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.
- During concomitant use of Diclofenac Sodium Extended-release Tablets
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 Extended-release Tablets
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; Renal Toxicity and Hyperkalemia) . - When these drugs are administered concomitantly, patients should be adequately hydrated. Assess renal function at the beginning of the concomitant treatment and periodically thereafter.
Hepatotoxicity
In clinical trials of diclofenac-containing products, meaningful elevations (i.e., more than 3 times the ULN) of AST (SGOT) were observed in about 2% of approximately 5,700 patients at some time during diclofenac treatment (ALT was not measured in all studies).
In a large, open-label, controlled trial of 3,700 patients treated with oral diclofenac sodium for 2 to 6 months, patients were monitored first at 8 weeks and 1,200 patients were monitored again at 24 weeks. Meaningful elevations of ALT and/or AST occurred in about 4% of patients and included marked elevations (greater than 8 times the ULN) in about 1% of the 3,700 patients. In that open-label study, a higher incidence of borderline (less than 3 times the ULN), moderate (3 - 8 times the ULN), and marked (greater than 8 times the ULN) elevations of ALT or AST was observed in patients receiving diclofenac when compared to other NSAIDs. Elevations in transaminases were seen more frequently in patients with osteoarthritis than in those with rheumatoid arthritis.
Almost all meaningful elevations in transaminases were detected before patients became symptomatic. Abnormal tests occurred during the first 2 months of therapy with diclofenac in 42 of the 51 patients in all trials who developed marked transaminase elevations.
In postmarketing reports, cases of drug-induced hepatotoxicity have been reported in the first month, and in some cases, the first 2 months of therapy, but can occur at any time during treatment with diclofenac. Postmarketing surveillance has reported cases of severe hepatic reactions, including liver necrosis, jaundice, fulminant hepatitis with and without jaundice, and liver failure. Some of these reported cases resulted in fatalities or liver transplantation.
In a European retrospective population-based, case-controlled study, 10 cases of diclofenac associated drug-induced liver injury with current use compared with non-use of diclofenac were associated with a statistically significant 4-fold adjusted odds ratio of liver injury. In this particular study, based on an overall number of 10 cases of liver injury associated with diclofenac, the adjusted odds ratio increased further with female gender, doses of 150 mg or more, and duration of use for more than 90 days.
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 Extended-release Tablets 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 “flulike” symptoms). If clinical signs and symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, etc.), discontinue Diclofenac Sodium Extended release Tablets immediately, and perform a clinical evaluation of the patient.
To minimize the potential risk for an adverse liver related event in patients treated with Diclofenac Sodium Extended-release Tablets, use the lowest effective dose for the shortest duration possible. Exercise when prescribing Diclofenac Sodium Extended-release Tablets with concomitant drugs that are known to be potentially hepatotoxic (e.g., acetaminophen, antibiotics, anti-epileptics).
No information is available from controlled clinical studies regarding the use of Diclofenac Sodium Extended-release Tablets in patients with advanced renal disease. The renal effects of Diclofenac Sodium Extended-release Tablets may hasten the progression of renal dysfunction in patients with preexisting renal disease.
Correct volume status in dehydrated or hypovolemic patients prior to initiating Diclofenac Sodium Extended-release Tablets. Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia during use of Diclofenac Sodium Extended-release Tablets (see
PRECAUTIONS; Drug Interactions). Avoid the use of Diclofenac Sodium Extended-release Tablets in patients with advanced renal disease unless the benefits are expected to outweigh the risk of worsening renal function. If Diclofenac Sodium Extended-release Tablets are used in patients with advanced renal disease, monitor patients for signs of worsening renal function.
Table 2: Clinically Significant Drug Interactions with Diclofenac
Drugs That Interfere with Hemostasis | |
Clinical Impact: | |
Intervention: | Monitor patients with concomitant use of Diclofenac Sodium Extended-release Tablets 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; Hematological Toxicity) . |
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; Gastrointestinal Bleeding, Ulceration, and Perforation). |
Intervention: | Concomitant use of Diclofenac Sodium Extended-release Tablets and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding ( see WARNINGS; Hematological Toxicity). Diclofenac Sodium Extended-release Tablets are not a substitute for low dose aspirin for cardiovascular protection. |
ACE Inhibitors, Angiotensin Receptor Blockers, and Beta-Blockers | |
Clinical Impact: | |
Intervention: | |
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 Extended-release Tablets with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects ( see WARNINGS; Renal Toxicity and Hyperkalemia) . |
Digoxin | |
Clinical Impact: | The concomitant use of diclofenac with digoxin has been reported to increase the serum concentration and prolong the half-life of digoxin. |
Intervention: | During concomitant use of Diclofenac Sodium Extended-release Tablets 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 prostaglandin synthesis. |
Intervention: | During concomitant use of Diclofenac Sodium Extended-release Tablets and lithium, monitor patients for signs of lithium toxicity. |
Methotrexate | |
Clinical Impact: | Concomitant use of NSAIDs and methotrexate may increase the risk for methotrexate (e.g., neutropenia, thrombocytopenia, renal dysfunction). |
Intervention: | During concomitant use of Diclofenac Sodium Extended-release Tablets and methotrexate, monitor patients for methotrexate toxicity. |
Cyclosporine | |
Clinical Impact: | Concomitant use of Diclofenac Sodium Extended-release Tablets and cyclosporine may increase cyclosporine’s nephrotoxicity. |
Intervention: | During concomitant use of Diclofenac Sodium Extended-release Tablets and cyclosporine, monitor patients for signs of worsening renal function. |
NSAIDs and Salicylates | |
Clinical Impact: | Concomitant use of diclofenac with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity, with little or no increase in efficacy ( see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation). |
Intervention: | The concomitant use of diclofenac with other NSAIDs or salicylates is not recommended. |
Pemetrexed | |
Clinical Impact: | Concomitant use of Diclofenac Sodium Extended-release Tablets and pemetrexed may increase the risk of pemetrexed-associated myelosuppression, renal, and GI toxicity (see the pemetrexed prescribing information). |
Intervention: | During concomitant use of Diclofenac Sodium Extended-release Tablets and pemetrexed, in patients with renal impairment whose creatinine clearance ranges from 45 to 79 mL/min, monitor for myelosuppression, renal, and GI toxicity. NSAIDs with short elimination half-lives (e.g., diclofenac, indomethacin) should be avoided for a period of two days before, the day of, and two days following administration of pemetrexed. In the absence of data regarding potential interaction between pemetrexed and NSAIDs with longer half-lives (e.g., meloxicam, nabumetone), patients taking these NSAIDs should interrupt dosing for at least five days before, the day of, and two days following pemetrexed administration. |
CYP2C9 Inhibitors or Inducers | |
Clinical Impact: | Diclofenac is metabolized by cytochrome P450 enzymes, predominantly by CYP2C9. Co-administration of diclofenac with CYP2C9 inhibitors (e.g., voriconazole) may enhance the exposure and toxicity of diclofenac whereas co-administration with CYP2C9 inducers (e.g., rifampin) may lead to compromised efficacy of diclofenac. |
Intervention: | A dosage adjustment may be warranted when diclofenac is administered with CYP2C9 inhibitors or inducers (see CLINICAL PHARMACOLOGY; Pharmacokinetics). |
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis
Long-term carcinogenicity studies in rats given diclofenac sodium up to 2 mg/kg/day (approximately 0.1 times the maximum recommended human dose [MRHD] of Diclofenac Sodium Extended-release Tablets, 200 mg/day, based on body surface area [BSA] comparison) have revealed no significant increase in tumor incidence. A 2-year carcinogenicity study conducted in mice employing diclofenac sodium at doses up to 0.3 mg/kg/day (approximately 0.007 times the MRHD based on BSA comparison) in males and 1 mg/kg/day (approximately 0.02 times the MRHD based on BSA comparison) in females did not reveal any oncogenic potential.
Mutagenesis
Diclofenac sodium did not show mutagenic activity in in vitro point mutation assays in mammalian (mouse lymphoma) and microbial (yeast, Ames) test systems and was nonmutagenic in several mammalian in vitro and in vivo tests, including dominant lethal and male germinal epithelial chromosomal studies in mice, and nucleus anomaly and chromosomal aberration studies in Chinese hamsters.
Impairment of Fertility
Diclofenac sodium administered to male and female rats at 4 mg/kg/day (approximately 0.2 times the MRHD based on BSA comparison) did not affect fertility.
Based on the mechanism of action, the use of prostaglandin-mediated NSAIDs, including Diclofenac Sodium Extended-release Tablets, may delay or prevent rupture of ovarian follicles, which has been associated with reversible infertility in some women. Published animal studies have shown that administration of prostaglandin synthesis inhibitors has the potential to disrupt prostaglandin-mediated follicular rupture required for ovulation.
Small studies in women treated with NSAIDs have also shown a reversible delay in ovulation. Consider withdrawal of NSAIDs, including Diclofenac Sodium Extended-release Tablets, in women who have difficulties conceiving or who are undergoing investigation of infertility.