Summary: The relationship between dosage, prothrombin ratio, and steady‐state plasma concentrations of warfarin and warfarin‐alcohol, were determined in 43 patients regularly attending an anticoagulant clinic. The warfarin and warfarin‐alcohol concentrations were determined by a gas chromatographic mass spectroscopic (GC/MS) method. A significant correlation was found between the dose and the plasma level of warfarin. There was no significant correlation between the prothrombin ratio and the dose of warfarin, the steady‐state plasma levels of warfarin or warfarin‐alcohol, or the sum of their plasma concentrations. Measurement of the plasma levels of warfarin and warfarin‐alcohol is likely to be of little help clinically other than to detect failure of compliance or malabsorption.
|Number of pages||4|
|Journal||Australian and New Zealand Journal of Medicine|
|Publication status||Published - Oct 1979|