diflunisal (Dolobid)

Introduction

Tradename Dolobid.

Dosage

100 mg loading dose, then 500 mg PO every 12 hours.

Tabs: 250, 500 mg.

Pharmacokinetics

• food deceases the rate, but not extent of diflusinal absorption
• diflusinal elimination is dose-dependent

elimination via liver

1/2life = 8-12 hours

1/2life = 5-20 hours

protein binding = >99 %

elimination by hemodialysis = -

elimination by peritoneal dialysis = -

Adverse effects

• nausea/vomiting
• peptic ulceration
• gastrointestinal bleeding
• dizziness
• drowsiness
• edema

• drug adverse effects of NSAIDs

Drug interactions

• aluminum & magnesium hydroxide may decrease diflunisal absorption
• diflunisal may decrease renal elimination of:
  • Li+
  • digoxin
  • methotrexate
• diflunisal may decrease steady state warfarin concentrations but does not appear to affect anticoagulant response
• bioavailablity of diflunisal is decreased by coadministration of aspirin

• drug interaction(s) of cholinesterase inhibitors with NSAIDs
• drug interaction(s) of lithium carbonate with NSAIDs
• drug interaction(s) of NSAIDs with oral contraceptive
• drug interaction(s) of NSAIDs with SSRIs
• drug interaction(s) of NSAIDs with antidepressants
• drug interaction(s) of aspirin with NSAIDs
• drug interaction(s) of apixaban with NSAIDs
• drug interaction(s) of warfarin with NSAIDs
• drug interaction(s) of NSAIDs with beta blockers
• drug interaction(s) of NSAIDs with ARBs
• drug interaction(s) of NSAIDs with aldosterone antagonis
• drug interaction(s) of NSAIDs with glucocorticoid
• drug interaction(s) of NSAIDs, diuretics & angiotensin II receptor antagonists
• drug interaction(s) of NSAIDs, diuretics & ACE inhibitors
• drug interaction(s) of NSAIDs with ACE inhibitors
• drug interaction(s) of NSAIDs & antihypertensives
• drug interaction(s) of NSAIDs & loop diuretics
• drug interaction(s) of NSAIDs & aspirin

Laboratory

• specimen:
  • serum, plasma (EDTA), urine
  • stable for at least 14 days at -20 degrees C
• methods:
  • serum/plasma: HPLC, GC, fluorometry
  • urine: GC, HPLC
• interferences:
  • diflunisal interferes with FPIA for salicylate

More general terms

• non-steroidal anti-inflammatory agent (NSAID)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3059