Diflunisal Disease Interactions

Nonsteroidal anti-inflammatory drugs (NSAIDs) are contraindicated in patients with 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. 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. Since cross-reactivity between aspirin and other NSAIDs has been reported in such aspirin-sensitive patients, therapy with any NSAID should be avoided in patients with this form of aspirin sensitivity. NSAIDs should be used with caution in patients with preexisting asthma (without known aspirin sensitivity), and these patients should be monitored for changes in the signs and symptoms of asthma.

Fluid retention and edema have been reported in association with the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Therapy with NSAIDs should be administered cautiously in patients with preexisting fluid retention, hypertension, or a history of heart failure. Blood pressure and cardiovascular status should be monitored closely during the initiation of NSAID treatment and throughout the course of therapy.

Nonsteroidal anti-inflammatory drugs (NSAIDs) 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 develop at any time, with or without warning symptoms. NSAIDs should be used with caution in patients with history of peptic ulcer disease and/or GI bleeding, as these patients had a greater than 10-fold increased risk for developing a GI bleed compared to patients without these risk factors. Caution is also advised if NSAIDs are prescribed to patients with other factors that increase risk of GI bleeding, such as: prolonged NSAID therapy; concomitant use of oral corticosteroids, antiplatelet agents (e.g., aspirin), anticoagulants, selective serotonin reuptake inhibitors; alcohol use; smoking; history of gastrointestinal surgery or anastomosis, older age; poor general health status; and advanced liver disease and/or coagulopathy. Particular vigilance is necessary when treating elderly or debilitated patients since most postmarketing reports of fatal GI events occurred in these patients.

Long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) has resulted in renal papillary necrosis and other renal injury. Renal toxicity has been seen in patients in whom renal prostaglandins have a compensatory role in the maintenance of renal perfusion: in such patients, NSAIDs may cause a dose-dependent reduction in prostaglandin synthesis and, secondarily, in renal blood flow, which may precipitate overt renal decompensation. Patients at greatest risk for this reaction include the elderly, those with impaired renal function, dehydration, hypovolemia, heart failure, or liver dysfunction, and those taking diuretics, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers; discontinuation of NSAID therapy will usually lead to recovery to the pretreatment state. No information is available regarding use NSAIDs in patients with advanced renal disease; the renal effects of NSAIDs may hasten the progression of renal dysfunction in patients with preexisting renal disease. Volume status should be corrected in dehydrated or hypovolemic patients prior to initiating treatment. Renal function should be monitored during therapy in patients with renal or liver dysfunction, heart failure, dehydration, or hypovolemia. NSAIDs should be avoided in patients with advanced renal disease unless the benefits are expected to outweigh the risk of worsening renal function; if an NSAID is used in such patients, they should be monitored for signs of worsening renal function.

The use of salicylates, primarily aspirin, in children with varicella infections or influenza-like illnesses has been associated with an increased risk of Reye's syndrome. Although a causal relationship has not been established, the majority of evidence to date seems to support the association. Most authorities, including the American Academy of Pediatrics Committee on Infectious Diseases, recommend avoiding the use of salicylates in children and teenagers with known or suspected varicella or influenza and during presumed outbreaks of influenza. If antipyretic or analgesic therapy is indicated under these circumstances, acetaminophen may be an appropriate alternative. The same precautions should also be observed with related agents such as salicylamide or diflunisal because of their structural and pharmacological similarities to salicylate.

Anemia has been reported in patients treated with nonsteroidal anti-inflammatory drugs (NSAIDs). This may be due to fluid retention, occult/gross blood loss, or an incompletely described effect on erythropoiesis. Hemoglobin or hematocrit should be monitored in patients with any signs/symptoms of anemia or blood loss, especially during long-term therapy. NSAIDs may increase risk of bleeding events; comorbid conditions (e.g., coagulation disorders; concomitant use of warfarin/other anticoagulants, antiplatelet agents, serotonin/serotonin norepinephrine reuptake inhibitors) may increase this risk, and patients with these conditions should be monitored for signs of bleeding. Therapy with NSAIDs should be administered cautiously in patients with or predisposed to anemia. Clinical monitoring of hematopoietic function may be appropriate, particularly during chronic therapy.

Borderline elevations of 1 or more liver tests may occur in up to 15% of patients treated with nonsteroidal anti-inflammatory drugs (NSAIDs). These laboratory abnormalities may progress, remain unchanged, or regress with continuing therapy. Elevations of ALT or AST (at least 3 times the upper limit of normal) have been reported in about 1% of patients in clinical trials. In addition, rare (sometimes fatal) cases of severe hepatotoxicity, including liver necrosis, hepatic failure, jaundice, and fulminant hepatitis have been reported. Therapy with NSAIDs should be administered cautiously in patients with preexisting liver disease. Periodic monitoring of liver function is recommended during prolonged therapy. NSAIDs are also highly protein-bound and some are extensively metabolized by the liver. Metabolic activity and/or plasma protein binding may be altered in patients with hepatic impairment. A dosage reduction may be required in some cases.

Nonsteroidal anti-inflammatory drugs (NSAIDs) reversibly inhibit platelet adhesion and aggregation and may prolong bleeding time in some patients. With the exception of aspirin, the platelet effects seen with most NSAIDs at usual recommended dosages are generally slight and of relatively short duration but may be more pronounced in patients with underlying hemostatic abnormalities. Thrombocytopenia has also been reported rarely during NSAID use. Therapy with NSAIDs should be administered cautiously in patients with significant active bleeding or a hemorrhagic diathesis, including hemostatic and/or coagulation defects associated with hemophilia, vitamin K deficiency, hypoprothrombinemia, thrombocytopenia, thrombocytopathy, or severe hepatic impairment. NSAIDs that selectively inhibit cyclooxygenase-2 (i.e., COX-2 inhibitors) do not appear to affect platelet function or bleeding time at indicated dosages and may be preferable if risk of bleeding is a concern.