pentoxifylline (Trental)

Introduction

Tradename: Trental.

Indications

• treatment of intermittent claudication associated with peripheral vascular disease (PVD)
  • a structured exercise program is the treatment of choice & superior to pentoxifylline for PVD
• treatment of severe alcoholic hepatitis*
• treatment of venous ulceration*

* may be useful MediCal: intermittent claudication & over 65 years or diabetic

Dosage

• 400 mg PO TID
• 800 mg PO TID used for venous stasis ulcers
  • increased incidence of adverse effects (nausea, dizziness)
• re-evaluate in 2 months & discontinue if no improvement
• try 400 mg BID if excessive side effects occur

Tabs: (controlled-release): 400 mg.

Pharmacokinetics

• peak levels 1 hour after oral administration
• 1st pass metabolism in liver
• two active metabolites
  • 5-8 fold higher plasma levels than parent compound
  • eliminated in urine (< 4% recovered in feces)
• elimination 1/2life
  • parent compound: 0.4-0.8 hours
  • metabolites: 1-1.6 hours
• elimination prolonged in patients with cirrhosis
• renal insufficieny can prolong clearance of metabolites

elimination via liver

1/2life = 0.4-0.8 hours

Adverse effects

• not common (1-10%)
  • dyspepsia, nausea/vomiting, dizziness, headache
• uncommon (< 1%)
  • mild hypotension, angina, agitation, blurred vision, earache
• other
  • diarrhea
  • tremor

Drug interactions

• anticoagulants in combination may increase risk of bleeding or increase prothrombin time, but no definitive proof

Mechanism of action

• improves blood flow by decreasing viscosity
• enhances tissue oxygenation
• reduces plasma fibrinogen & increases fibrinolytic activity
• inhibits platelet aggregation
• increase erythrocyte flexibility
• stimulates synthesis & release of prostacyclin
• antagonizes adenosine receptor
• diminishes tumor necrosis factor-alpha

More general terms

• hematologic agent

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=4740