Warfarin elimination and responsiveness in patients with renal dysfunction

Area of Science:

• Pharmacology
• Nephrology

Background:

• Warfarin is a common anticoagulant.
• Renal dysfunction may alter drug metabolism and elimination.

Purpose of the Study:

• To investigate warfarin pharmacokinetics and pharmacodynamics in patients with renal dysfunction.
• To compare warfarin half-life and responsiveness between renal patients and healthy controls.

Main Methods:

• Estimated plasma warfarin half-life in four patients with renal dysfunction and five normal controls.
• Evaluated hypoprothrombinemic responsiveness to a single oral warfarin dose (0.75 mg/kg).

Main Results:

• Mean warfarin half-life was significantly shorter in renal patients (29.9 hours) than in normal controls (44.8 hours).
• A positive correlation was observed between warfarin half-life and creatinine clearance.
• Pharmacologic responsiveness to warfarin was comparable between the groups.

Conclusions:

• Renal dysfunction does not appear to increase susceptibility to warfarin's hypoprothrombinemic effect.
• Pharmacokinetic changes in warfarin metabolism in renal impairment do not translate to altered pharmacologic response.