diflunisal (Dolobid)

Tradename Dolobid. Dose: 100 mg loading dose, then 500 mg PO every 12 hours. Tabs: 250, 500 mg. Pharmacokinetics: 1) food deceases the rate, but not extent of diflusinal absorption 2) diflusinal elimination is dose-dependent Adverse effects: 1) nausea/vomiting 2) peptic ulceration 3) gastrointestinal bleeding 4) dizziness 5) drowsiness 6) edema Drug interactions: 1) aluminum & magnesium hydroxide may decrease diflunisal absorption 2) diflunisal may decrease renal elimination of: a) Li⁺ b) digoxin c) methotrexate 3) diflunisal may decrease steady state warfarin concentrations but does not appear to affect anticoagulant response 4) bioavailablity of diflunisal is decreased by coadministration of aspirin Laboratory: 1) specimen: a) serum, plasma (EDTA), urine b) stable for at least 14 days at -20 degrees C 2) methods: a) serum/plasma: HPLC, GC, fluorometry b) urine: GC, HPLC 3) interferences: -> diflunisal interferes with FPIA for salicylate

Interactions

drug interactions drug adverse effects of NSAIDs monitor with non steroidal anti-inflammatory agents (NSIADs)

Properties

INHIBITS: cyclooxygenase MISC-INFO: elimination route LIVER 1/2life 8-12 HOURS 5-20 HOURS therapeutic-range >40 UG/ML protein-binding >99% elimination by hemodialysis - peritoneal dialysis - pregnancy-category C safety in lactation -