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Diflunisal

Pronunciation

Pronunciation

(dye FLOO ni sal)

Index Terms

  • Dolobid

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Generic: 500 mg

Pharmacologic Category

  • Analgesic, Nonopioid
  • Nonsteroidal Anti-inflammatory Drug (NSAID), Oral

Pharmacology

Reversibly inhibits cyclooxygenase-1 and 2 (COX-1 and 2) enzymes, which results in decreased formation of prostaglandin precursors; has antipyretic, analgesic, and anti-inflammatory properties.

Other proposed mechanisms not fully elucidated (and possibly contributing to the anti-inflammatory effect to varying degrees) include inhibiting chemotaxis, altering lymphocyte activity, inhibiting neutrophil aggregation/activation, and decreasing proinflammatory cytokine levels.

Absorption

Well absorbed

Distribution

7.53 L (increases to 16.2 L in renal impairment)

Metabolism

Extensive metabolism to glucuronide conjugates; predominant metabolite is the ether (phenolic) glucuronide conjugate followed by less predominant ester glucuronide; biotransformation to its phenolic glucuronide conjugates may become saturable

Excretion

Urine (~90% as glucuronide conjugates); feces (<5%)

Onset of Action

Analgesic: ~1 hour; maximal effect: 2 to 3 hours

Time to Peak

Serum: 2 to 3 hours

Duration of Action

8 to12 hours

Half-Life Elimination

8 to 12 hours; prolonged with renal impairment

Protein Binding

>99%

Use: Labeled Indications

Mild to moderate pain: For acute or long-term use for symptomatic treatment of mild to moderate pain

Osteoarthritis/Rheumatoid arthritis (RA): For acute or long-term use for symptomatic relief of osteoarthritis and RA

Contraindications

Known hypersensitivity to diflunisal or the excipients; the treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery; patients who have experienced asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs

Dosing: Adult

Mild to moderate pain: Oral: Initial: 1 g, followed by 500 mg every 12 hours; maintenance doses of 500 mg every 8 hours may be necessary in some patients; maximum daily dose: 1.5 g

Dosage adjustments: A lower dosage may be appropriate depending on pain severity, patient response, or weight; Initial: 500 mg, followed by 250 mg every 8 to 12 hours; maximum daily dose: 1.5 g

Arthritis: Oral: 500 mg to 1 g daily in 2 divided doses; maximum daily dose: 1.5 g

Dosing: Geriatric

Mild to moderate pain: Oral: Initial: 500 mg, followed by 250 mg every 8-12 hours; maximum daily dose: 1.5 g

Arthritis: Refer to adult dosing.

Dosing: Renal Impairment

No dosage adjustment provided in the manufacturer’s labeling; however the following adjustments have been used by some clinicians (Aronoff, 2007):

CrCl <50 mL/minute: Administer 50% of normal dose.

Hemodialysis: No supplement required.

CAPD: No supplement required.

Dosing: Hepatic Impairment

No dosage adjustment provided in manufacturer’s labeling; use with caution.

Administration

Tablet should be swallowed whole; do not crush or chew.

Dietary Considerations

Should be taken with food to decrease GI upset.

Storage

Store at 20°C to 25°C (68°F to 77°F); excursions are permitted between 15°C and 30°C (59°F and 86°F).

Drug Interactions

5-ASA Derivatives: Nonsteroidal Anti-Inflammatory Agents may enhance the nephrotoxic effect of 5-ASA Derivatives. Monitor therapy

ACE Inhibitors: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Specifically, the combination may result in a significant decrease in renal function. Nonsteroidal Anti-Inflammatory Agents may diminish the antihypertensive effect of ACE Inhibitors. Monitor therapy

Agents with Antiplatelet Properties (e.g., P2Y12 inhibitors, NSAIDs, SSRIs, etc.): May enhance the antiplatelet effect of other Agents with Antiplatelet Properties. Monitor therapy

Alcohol (Ethyl): May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Specifically, the risk of GI bleeding may be increased with this combination. Monitor therapy

Aliskiren: Nonsteroidal Anti-Inflammatory Agents may diminish the antihypertensive effect of Aliskiren. Nonsteroidal Anti-Inflammatory Agents may enhance the nephrotoxic effect of Aliskiren. Management: Monitor renal function periodically in patients receiving aliskiren and any nonsteroidal anti-inflammatory agent. Patients at elevated risk of renal dysfunction include those who are elderly, are volume depleted, or have pre-existing renal dysfunction. Monitor therapy

Aminoglycosides: Nonsteroidal Anti-Inflammatory Agents may decrease the excretion of Aminoglycosides. Data only in premature infants. Monitor therapy

Angiotensin II Receptor Blockers: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Specifically, the combination may result in a significant decrease in renal function. Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Angiotensin II Receptor Blockers. The combination of these two agents may also significantly decrease glomerular filtration and renal function. Monitor therapy

Anticoagulants: Agents with Antiplatelet Properties may enhance the anticoagulant effect of Anticoagulants. Monitor therapy

Anticoagulants: Nonsteroidal Anti-Inflammatory Agents may enhance the anticoagulant effect of Anticoagulants. Monitor therapy

Antidepressants (Tricyclic, Tertiary Amine): May enhance the antiplatelet effect of NSAID (Nonselective). Monitor therapy

Apixaban: NSAID (Nonselective) may enhance the adverse/toxic effect of Apixaban. Specifically, the risk of bleeding may be increased. Management: A comprehensive risk to benefit assessment should be done for all patients before any concurrent use of apixaban and nonsteroidal anti-inflammatory drugs (NSAIDs). If combined, monitor patients extra closely for signs and symptoms of bleeding. Consider therapy modification

Beta-Blockers: Nonsteroidal Anti-Inflammatory Agents may diminish the antihypertensive effect of Beta-Blockers. Exceptions: Levobunolol; Metipranolol. Monitor therapy

Bile Acid Sequestrants: May decrease the absorption of Nonsteroidal Anti-Inflammatory Agents. Consider therapy modification

Bisphosphonate Derivatives: Nonsteroidal Anti-Inflammatory Agents may enhance the adverse/toxic effect of Bisphosphonate Derivatives. Both an increased risk of gastrointestinal ulceration and an increased risk of nephrotoxicity are of concern. Monitor therapy

Collagenase (Systemic): Agents with Antiplatelet Properties may enhance the adverse/toxic effect of Collagenase (Systemic). Specifically, the risk of injection site bruising and/or bleeding may be increased. Monitor therapy

Corticosteroids (Systemic): May enhance the adverse/toxic effect of NSAID (Nonselective). Monitor therapy

CycloSPORINE (Systemic): Nonsteroidal Anti-Inflammatory Agents may enhance the nephrotoxic effect of CycloSPORINE (Systemic). Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of CycloSPORINE (Systemic). CycloSPORINE (Systemic) may increase the serum concentration of Nonsteroidal Anti-Inflammatory Agents. Specifically, elevated diclofenac concentrations have been reported. Management: Consider alternatives to nonsteroidal anti-inflammatory agents (NSAIDs). Monitor for evidence of nephrotoxicity, as well as increased serum cyclosporine concentrations and systemic effects (e.g., hypertension) during concomitant therapy with NSAIDs. Consider therapy modification

Dabigatran Etexilate: NSAID (Nonselective) may enhance the adverse/toxic effect of Dabigatran Etexilate. Specifically, the risk of bleeding may be increased. Management: A comprehensive risk to benefit assessment should be done for all patients before any concurrent use of dabigatran and nonsteroidal anti-inflammatory drugs (NSAIDs). If combined, monitor patients extra closely for signs and symptoms of bleeding. Consider therapy modification

Dasatinib: May enhance the anticoagulant effect of Agents with Antiplatelet Properties. Monitor therapy

Deferasirox: Nonsteroidal Anti-Inflammatory Agents may enhance the adverse/toxic effect of Deferasirox. Specifically, the risk for GI ulceration/irritation or GI bleeding may be increased. Monitor therapy

Deoxycholic Acid: Agents with Antiplatelet Properties may enhance the adverse/toxic effect of Deoxycholic Acid. Specifically, the risk for bleeding or bruising in the treatment area may be increased. Monitor therapy

Desmopressin: Nonsteroidal Anti-Inflammatory Agents may enhance the adverse/toxic effect of Desmopressin. Monitor therapy

Dexketoprofen: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Diclofenac (Systemic): May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Management: Seek alternatives to the combined use of diclofenac with other nonsteroidal anti-inflammatory agents (NSAIDs). Avoid the use of diclofenac/misoprostol with other NSAIDs. Consider therapy modification

Digoxin: Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of Digoxin. Monitor therapy

Drospirenone: Nonsteroidal Anti-Inflammatory Agents may enhance the hyperkalemic effect of Drospirenone. Monitor therapy

Edoxaban: NSAID (Nonselective) may enhance the adverse/toxic effect of Edoxaban. Specifically, the risk of bleeding may be increased. Management: A comprehensive risk to benefit assessment should be done for all patients before any concurrent use of edoxaban and nonsteroidal anti-inflammatory drugs (NSAIDs). If combined, monitor patients extra closely for signs and symptoms of bleeding. Consider therapy modification

Eplerenone: Nonsteroidal Anti-Inflammatory Agents may diminish the antihypertensive effect of Eplerenone. Nonsteroidal Anti-Inflammatory Agents may enhance the hyperkalemic effect of Eplerenone. Monitor therapy

Floctafenine: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Glucosamine: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Haloperidol: Nonsteroidal Anti-Inflammatory Agents may enhance the adverse/toxic effect of Haloperidol. Specifically including drowsiness and confusion. Monitor therapy

Herbs (Anticoagulant/Antiplatelet Properties) (eg, Alfalfa, Anise, Bilberry): May enhance the adverse/toxic effect of Agents with Antiplatelet Properties. Bleeding may occur. Consider therapy modification

Herbs (Anticoagulant/Antiplatelet Properties) (eg, Alfalfa, Anise, Bilberry): May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Bleeding may occur. Management: Concomitant treatment with these agents should generally be avoided. If used concomitantly, increased diligence in monitoring for adverse effects (eg, bleeding, bruising, altered mental status due to CNS bleeds) must be employed. Consider therapy modification

HydrALAZINE: Nonsteroidal Anti-Inflammatory Agents may diminish the antihypertensive effect of HydrALAZINE. Monitor therapy

Ibritumomab: Agents with Antiplatelet Properties may enhance the adverse/toxic effect of Ibritumomab. Both agents may contribute to impaired platelet function and an increased risk of bleeding. Monitor therapy

Ibrutinib: May enhance the adverse/toxic effect of Agents with Antiplatelet Properties. Monitor therapy

Ketorolac (Nasal): May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Ketorolac (Systemic): May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Limaprost: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Lithium: Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of Lithium. Consider therapy modification

Loop Diuretics: Nonsteroidal Anti-Inflammatory Agents may diminish the diuretic effect of Loop Diuretics. Loop Diuretics may enhance the nephrotoxic effect of Nonsteroidal Anti-Inflammatory Agents. Management: Monitor for evidence of kidney injury or decreased therapeutic effects of loop diuretics with concurrent use of an NSAID. Consider avoiding concurrent use in CHF or cirrhosis. Concomitant use of bumetanide with indomethacin is not recommended. Consider therapy modification

Methotrexate: Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of Methotrexate. Management: Alternative anti-inflammatory therapy should be considered whenever possible, especially if the patient is receiving higher, antineoplastic doses of methotrexate. Consider therapy modification

Morniflumate: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Multivitamins/Fluoride (with ADE): May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Multivitamins/Minerals (with AE, No Iron): May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: May enhance the adverse/toxic effect of other Nonsteroidal Anti-Inflammatory Agents. Monitor therapy

NSAID (COX-2 Inhibitor): Nonsteroidal Anti-Inflammatory Agents may enhance the adverse/toxic effect of NSAID (COX-2 Inhibitor). Avoid combination

Obinutuzumab: Agents with Antiplatelet Properties may enhance the adverse/toxic effect of Obinutuzumab. Specifically, the risk of serious bleeding-related events may be increased. Monitor therapy

Omacetaxine: Nonsteroidal Anti-Inflammatory Agents may enhance the adverse/toxic effect of Omacetaxine. Specifically, the risk for bleeding-related events may be increased. Management: Avoid concurrent use of nonsteroidal antiinflammatory drugs (NSAIDs) with omacetaxine in patients with a platelet count of less than 50,000/uL. Avoid combination

Omega-3 Fatty Acids: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

PEMEtrexed: NSAID (Nonselective) may increase the serum concentration of PEMEtrexed. Management: Patients with mild-to-moderate renal insufficiency (estimated creatinine clearance 45-79 mL/min) should avoid NSAIDs for 2-5 days prior to, the day of, and 2 days after pemetrexed. Consider therapy modification

Pentosan Polysulfate Sodium: May enhance the adverse/toxic effect of Agents with Antiplatelet Properties. Specifically, the risk of bleeding may be increased by concurrent use of these agents. Monitor therapy

Pentoxifylline: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Porfimer: Photosensitizing Agents may enhance the photosensitizing effect of Porfimer. Monitor therapy

Potassium-Sparing Diuretics: Nonsteroidal Anti-Inflammatory Agents may diminish the antihypertensive effect of Potassium-Sparing Diuretics. Nonsteroidal Anti-Inflammatory Agents may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Monitor therapy

PRALAtrexate: Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of PRALAtrexate. More specifically, NSAIDS may decrease the renal excretion of pralatrexate. Management: Closely monitor for increased pralatrexate serum levels and/or toxicity if used concomitantly with an NSAID. Monitor for decreased pralatrexate serum levels with NSAID discontinuation. Monitor therapy

Probenecid: May increase the serum concentration of Nonsteroidal Anti-Inflammatory Agents. Monitor therapy

Prostacyclin Analogues: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Prostaglandins (Ophthalmic): Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Prostaglandins (Ophthalmic). Nonsteroidal Anti-Inflammatory Agents may also enhance the therapeutic effects of Prostaglandins (Ophthalmic). Monitor therapy

Quinolone Antibiotics: Nonsteroidal Anti-Inflammatory Agents may enhance the neuroexcitatory and/or seizure-potentiating effect of Quinolone Antibiotics. Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of Quinolone Antibiotics. Monitor therapy

Rivaroxaban: NSAID (Nonselective) may enhance the adverse/toxic effect of Rivaroxaban. Specifically, the risk of bleeding may be increased. Management: A comprehensive risk to benefit assessment should be done for all patients before any concurrent use of rivaroxaban and nonsteroidal anti-inflammatory drugs (NSAIDs). If combined, monitor patients extra closely for signs and symptoms of bleeding. Consider therapy modification

Salicylates: NSAID (Nonselective) may enhance the adverse/toxic effect of Salicylates. An increased risk of bleeding may be associated with use of this combination. NSAID (Nonselective) may diminish the cardioprotective effect of Salicylates. Salicylates may decrease the serum concentration of NSAID (Nonselective). Exceptions: Choline Magnesium Trisalicylate. Consider therapy modification

Salicylates: Agents with Antiplatelet Properties may enhance the adverse/toxic effect of Salicylates. Increased risk of bleeding may result. Monitor therapy

Selective Serotonin Reuptake Inhibitors: May enhance the antiplatelet effect of NSAID (Nonselective). NSAID (Nonselective) may diminish the therapeutic effect of Selective Serotonin Reuptake Inhibitors. Management: Consider using alternative analgesics, when appropriate, and/or addition of a gastroprotective agent. Monitor patients closely for signs/symptoms of bleeding, and for evidence of diminished SSRI effectiveness with concurrent use. Consider therapy modification

Serotonin/Norepinephrine Reuptake Inhibitors: May enhance the antiplatelet effect of NSAID (Nonselective). Monitor therapy

Sodium Phosphates: May enhance the nephrotoxic effect of Nonsteroidal Anti-Inflammatory Agents. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with NSAIDs, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, maintain adequate hydration and monitor renal function closely. Consider therapy modification

Tacrolimus (Systemic): Nonsteroidal Anti-Inflammatory Agents may enhance the nephrotoxic effect of Tacrolimus (Systemic). Monitor therapy

Talniflumate: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Tenofovir Products: Nonsteroidal Anti-Inflammatory Agents may enhance the nephrotoxic effect of Tenofovir Products. Management: Seek alternatives to these combinations whenever possible. Avoid use of tenofovir with multiple NSAIDs or any NSAID given at a high dose. Consider therapy modification

Tenoxicam: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Avoid combination

Thiazide and Thiazide-Like Diuretics: May enhance the nephrotoxic effect of Nonsteroidal Anti-Inflammatory Agents. Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Thrombolytic Agents: Agents with Antiplatelet Properties may enhance the anticoagulant effect of Thrombolytic Agents. Monitor therapy

Tipranavir: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Tositumomab and Iodine I 131 Tositumomab: Agents with Antiplatelet Properties may enhance the adverse/toxic effect of Tositumomab and Iodine I 131 Tositumomab. Specifically, the risk of bleeding-related adverse events may be increased. Monitor therapy

Treprostinil: May enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Bleeding may occur. Monitor therapy

Urokinase: Agents with Antiplatelet Properties may enhance the anticoagulant effect of Urokinase. Avoid combination

Vancomycin: Nonsteroidal Anti-Inflammatory Agents may increase the serum concentration of Vancomycin. Monitor therapy

Verteporfin: Photosensitizing Agents may enhance the photosensitizing effect of Verteporfin. Monitor therapy

Vitamin E: May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Vitamin E (Oral): May enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy

Vitamin K Antagonists (eg, warfarin): NSAID (Nonselective) may enhance the anticoagulant effect of Vitamin K Antagonists. Consider therapy modification

Test Interactions

Falsely elevated increase in serum salicylate levels

Adverse Reactions

Frequency not always defined.

1% to 10%:

Central nervous system: Headache (3% to 9%), dizziness (1% to 3%), drowsiness (1% to 3%), fatigue (1% to 3%), insomnia (1% to 3%)

Dermatologic: Skin rash (3% to 9%)

Gastrointestinal: Diarrhea (3% to 9%), dyspepsia (3% to 9%), gastrointestinal pain (3% to 9%), nausea (3% to 9%), constipation (1% to 3%), flatulence (1% to 3%), vomiting (1% to 3%), gastrointestinal ulcer

Otic: Tinnitus (1% to 3%)

<1% (Limited to important or life-threatening): Agranulocytosis, anaphylactic reaction (acute), angioedema, anorexia, auditory impairment, blurred vision, bronchospasm, chest pain, cholestasis, confusion, cystitis, depression, diaphoresis, disorientation, DRESS syndrome, dry mucous membranes, dyspnea, dysuria, edema, eructation, erythema multiforme, esophagitis, exfoliative dermatitis, flushing, gastritis, gastrointestinal hemorrhage, gastrointestinal perforation, hallucination, hearing loss, hematuria, hemolytic anemia, hepatitis, hepatotoxicity (idiosyncratic; Chalasani 2014), hypersensitivity angiitis, hypersensitivity reaction, interstitial nephritis, jaundice, muscle cramps, necrotizing fasciitis, nephrotic syndrome, nervousness, palpitations, paresthesia, peptic ulcer, peripheral neuropathy, proteinuria, pruritus, renal failure, renal insufficiency, seizure, skin photosensitivity, Stevens-Johnson syndrome, stomatitis, syncope, tachycardia, thrombocytopenia, toxic epidermal necrolysis, tremor, urticaria, vasculitis, vertigo, weakness, wheezing

ALERT: U.S. Boxed Warning

Cardiovascular risk:

Nonsteroidal anti-inflammatory drugs (NSAIDs) may cause an increased risk of serious cardiovascular thrombotic reactions, myocardial infarction (MI), and stroke, which can be fatal. This risk may increase with duration of use. Patients with cardiovascular disease or risk factors for cardiovascular disease may be at greater risk.

Diflunisal is contraindicated for the treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.

GastrointestinaI risk:

NSAIDs cause an increased risk of serious gastrointestinal (GI) adverse reactions, including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These reactions can occur at any time during use and without warning symptoms. Elderly patients are at greater risk for serious GI reactions.

Warnings/Precautions

Concerns related to adverse effects:

• Anaphylactoid reactions: Even in patients without prior exposure anaphylactoid reactions may occur; patients with "aspirin triad" (bronchial asthma, aspirin intolerance, rhinitis) may be at increased risk. Do not use in patients who experience bronchospasm, asthma, rhinitis, or urticaria with NSAID or aspirin therapy.

• CNS effects: May cause drowsiness, dizziness, blurred vision, and other neurologic effects which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).

• Cardiovascular events: [U.S. Boxed Warning]: NSAIDs are associated with an increased risk of adverse cardiovascular thrombotic events, including MI and stroke. Risk may be increased with duration of use or preexisting cardiovascular risk factors or disease. Carefully evaluate individual cardiovascular risk profiles prior to prescribing. Use caution with fluid retention. Avoid use in heart failure (ACCF/AHA [Yancy, 2013]). Concurrent administration of ibuprofen, and potentially other nonselective NSAIDs, may interfere with aspirin’s cardioprotective effect. Use the lowest effective dose for the shortest duration of time, consistent with individual patient goals, to reduce risk of cardiovascular events; alternate therapies should be considered for patients at high risk.

• Gastrointestinal events: [U.S. Boxed Warning]: NSAIDs may increase risk of gastrointestinal irritation, inflammation, ulceration, bleeding, and perforation. These events may occur at any time during therapy and without warning. Use caution with a history of GI disease (bleeding or ulcers), concurrent therapy with aspirin, anticoagulants and/or corticosteroids, smoking, use of alcohol, the elderly or debilitated patients. Use the lowest effective dose for the shortest duration of time, consistent with individual patient goals, to reduce risk of GI adverse events; alternate therapies should be considered for patients at high risk. When used concomitantly with aspirin, a substantial increase in the risk of gastrointestinal complications (eg, ulcer) occurs; concomitant gastroprotective therapy (eg, proton pump inhibitors) is recommended (Bhatt, 2008).

• Hematologic effects: Platelet adhesion and aggregation may be decreased; may prolong bleeding time; patients with coagulation disorders or who are receiving anticoagulants should be monitored closely. Anemia may occur; patients on long-term NSAID therapy should be monitored for anemia. Rarely, NSAID use has been associated with potentially severe blood dyscrasias (eg, agranulocytosis, thrombocytopenia, aplastic anemia).

• Hyperkalemia: NSAID use may increase the risk of hyperkalemia, particularly in the elderly, diabetics, renal disease, and with concomitant use of other agents capable of inducing hyperkalemia (eg, ACE-inhibitors). Monitor potassium closely.

• Hypersensitivity syndrome: A hypersensitivity syndrome has been reported; monitor for constitutional symptoms and cutaneous findings; other organ dysfunction may be involved.

• Ophthalmic events: Blurred vision has been reported; refer for ophthalmologic evaluation if symptoms occur.

• Reye's syndrome: Diflunisal is a derivative of acetylsalicylic acid and therefore may be associated with Reye’s syndrome.

• Skin reactions: NSAIDs may cause serious skin adverse events including exfoliative dermatitis, Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN); discontinue use at first sign of skin rash or hypersensitivity.

Disease-related concerns:

• Asthma: Do not administer to patients with aspirin-sensitive asthma; severe bronchospasm may occur. Use caution in patients with other forms of asthma.

• Coronary artery bypass graft surgery: [U.S. Boxed Warning]: Use is contraindicated for treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery. Risk of MI and stroke may be increased with use following CABG surgery.

• Hepatic impairment: Use with caution in patients with decreased hepatic function. Closely monitor patients with any abnormal LFT. Severe hepatic reactions (eg, fulminant hepatitis, liver failure) have occurred with NSAID use, rarely; discontinue if signs or symptoms of liver disease develop, or if systemic manifestations occur.

• Hypertension: Use with caution; may cause new-onset hypertension or worsening of existing hypertension.

• Renal impairment: NSAID use may compromise existing renal function; dose-dependent decreases in prostaglandin synthesis may result from NSAID use, reducing renal blood flow which may cause renal decompensation. Patients with impaired renal function, dehydration, heart failure, liver dysfunction, those taking diuretics, and ACE inhibitors, and the elderly are at greater risk of renal toxicity. Rehydrate patient before starting therapy; monitor renal function closely. Not recommended for use in patients with advanced renal disease. Long-term NSAID use may result in renal papillary necrosis.

Other warnings/precautions:

• Surgical/dental procedures: Withhold for at least 4-6 half-lives prior to surgical or dental procedures.

Pregnancy Risk Factor

C

Pregnancy Considerations

Adverse events were not observed in the initial animal reproduction studies; therefore, the manufacturer classifies diflunisal as pregnancy category C. NSAID exposure during the first trimester is not strongly associated with congenital malformations; however, cardiovascular anomalies and cleft palate have been observed following NSAID exposure in some studies. The use of a NSAID close to conception may be associated with an increased risk of miscarriage. Nonteratogenic effects have been observed following NSAID administration during the third trimester including: Myocardial degenerative changes, prenatal constriction of the ductus arteriosus, fetal tricuspid regurgitation, failure of the ductus arteriosus to close postnatally; renal dysfunction or failure, oligohydramnios; gastrointestinal bleeding or perforation, increased risk of necrotizing enterocolitis; intracranial bleeding (including intraventricular hemorrhage), platelet dysfunction with resultant bleeding; pulmonary hypertension. Because they may cause premature closure of the ductus arteriosus, use of NSAIDs late in pregnancy should be avoided (use after 31 or 32 weeks gestation is not recommended by some clinicians). The chronic use of NSAIDs in women of reproductive age may be associated with infertility that is reversible upon discontinuation of the medication.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience nausea, vomiting, or diarrhea. Have patient report immediately to prescriber signs of severe cerebrovascular disease (change in strength on one side is greater than the other, trouble speaking or thinking, change in balance, or change in eyesight), signs of abdominal ulcers (very bad stomach or back pain; black, tarry, or bloody stools; vomiting blood or vomit that looks like coffee grounds; or weight gain or swelling that is not normal), signs of bleeding (vomiting blood or vomit that looks like coffee grounds; coughing up blood; blood in the urine; black, red, or tarry stools; bleeding from the gums; abnormal vaginal bleeding; bruises without a reason or that get bigger; or any bleeding that is very bad or that will not stop), signs of kidney problems (urinary retention, blood in urine, change in amount of urine passed, weight gain), signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes), shortness of breath, excessive weight gain, swelling of arm or leg, angina, tachycardia, severe headache, severe dizziness, severe abdominal pain, chills, joint pain, muscle pain, lack of appetite, loss of strength and energy, vision changes, eye pain, or severe eye irritation (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

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