DIFLUNISAL
(dye-floo'ni-sal)
Dolobid
Classifications: central nervous system agent; analgesic; nsaid
Prototype: Ibuprofen
Pregnancy Category: C

Availability

250 mg, 500 mg tablets

Actions

A long-acting nonsteroidal antiinflammatory drug (NSAID) unlike aspirin, in which, inhibition of platelet function and effect on bleeding time are dose related and reversible, lasting only about 24 h after drug is discontinued. Is a non-narcotic analgesic agent. Exerts mild antipyretic effect; therefore it is not used clinically for this purpose. Has some uricosuric activity at usual dosages.

Therapeutic Effects

This NSAID has peripheral analgesic properties by inhibition of prostaglandin synthesis. It is more potent than aspirin and acetaminophen in equianalgesic doses and has longer duration of effect.

Uses

Acute and long-term relief of mild to moderate pain and symptomatic treatment of osteoarthritis and rheumatoid arthritis.

Contraindications

Patients in whom aspirin or other NSAIDs precipitate an acute asthmatic attack (bronchospasm), urticaria, angioedema, severe rhinitis, or shock; active peptic ulcer, GI bleeding. Safe use during pregnancy (category C), lactation, or children <12 y is not established. Use during third trimester of pregnancy specifically contraindicated because NSAIDs are known to cause premature closure of ductus arteriosus in fetus.

Cautious Use

History of upper GI disease; impaired renal or hepatic function; compromised cardiac function, and other conditions associated with fluid retention; patients receiving diuretics; geriatric patients; hypertension; patients who may be adversely affected by prolonged bleeding time.

Route & Dosage

Pain Relief
Adult: PO 1000 mg followed by 500 mg q8–12h

Arthritis
Adult: PO 500–1000 mg/d in 2 divided doses (max: 1500 mg/d)

Administration

Oral

Adverse Effects (1%)

Body as a Whole: Hypersensitivity syndrome (fever, chills, rash, eosinophilia, changes in renal and hepatic function, anaphylactic reactions with bronchospasm). CNS: Headache, drowsiness, insomnia, dizziness, vertigo, light-headedness, fatigue, weakness, nervousness, confusion, disorientation. CV: Palpitation, tachycardia, peripheral edema. Special Senses: Tinnitus, hearing loss; blurred vision, reduced visual acuity, changes in color vision, scotomas, corneal deposits, retinal disturbances. GI: Nausea, GI pain, flatulence, GI bleeding, peptic ulcer, anorexia, eructation, cholestatic jaundice. Urogenital: Hematuria, proteinuria, interstitial nephritis, renal failure. Hematologic: Prolonged PT, anemia, decreased serum uric acid, transient elevations of liver function tests. Skin: Rash, toxic epidermal necrolysis, exfoliative dermatitis, urticaria. Other: Weight gain, hyperventilation, dyspnea, photosensitivity.

Diagnostic Test Interference

Diflunisal can lower serum uric acid concentrations by as much as 1.4 mg/dL and increased renal clearance of uric acid.

Interactions

Drug: antacids decrease diflunisal absorption; aspirin and other nsaids increase risk of GI bleeding; increases risk of warfarin-induced hypoprothrombinemia; increases methotrexate levels and toxicity.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Onset: 1 h. Peak: 2–3 h. Duration: 12 h. Distribution: Probably crosses placenta; distributed into breast milk. Metabolism: Metabolized in liver. Elimination: Excreted in urine. Half-Life: 8–12 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug