Performance of the Coumatrak system in a large anticoagulation clinic.

There is a need to monitor anticoagulation accurately, inexpensively, and rapidly. The accuracy and precision of a simple fingerstick method was studied in a large outpatient anticoagulation clinic using the Coumatrak method. The Coumatrak apparatus has been studied in the home setting, and three recent reports suggest that it is practical, accurate, and possibly superior to the standard method. These results differ from recently published studies. This technique was found to be less than acceptable in precision and accuracy. This method requires further study before it can be recommended for wide-spread use in making decisions for patient care.

Drug induced morphologic changes in the liver.

The pathologic evaluation of hepatic changes secondary to drug ingestion is a difficult task because of the limited histologic response of the liver to hepatotoxins. The majority of these pharmacologic agents produce cholestasis, hepatitis, or both. Some drugs will produce damage if given for a sufficient time and in sufficient amount; this reaction is termed predictable. Other agents cause injury only in a small number of individuals; this reaction is unrelated to dosage or duration of administration and is termed unpredictable. In time, after discontinuing the offending agent, morphologic alterations of the liver and clinical findings will revert to normal except in certain conditions. Some drugs will produce cirrhosis as a sequelae while others may progress to chronic hepatitis. The accurate and complete evaluation of hepatic morphology requires a thorough clinical history since the histologic changes of certain illnesses may mimic the changes of drug-induced hepatic damage. For the clinician, drug-induced hepatic injury is important because of the central function the liver plays in drug metabolism and its susceptibility to damage.