Eighty-six patients who required heparin therapy were randomly assigned to receive bovine or porcine heparin. Abnormal concentrations of alanine transaminase and aspartate transaminase developed during treatment in 59.3% and 26.7% of patients, respectively. Patient characteristics that significantly influenced the development of abnormal alanine transaminase concentrations were male sex and higher baseline enzyme values. Transaminase concentrations returned to normal in 80% of patients after heparin therapy was discontinued and in 20% during therapy. Analysis of transaminase concentrations in all 86 patients showed that 95% had some increase in enzymes during treatment. Mean maximal increase over baseline for all patients was 3.6 for alanine transaminase and 3.1 for aspartate transaminase (range, 1.0 to 15). Lactate dehydrogenase concentrations became abnormal in 35.7% of patients. Lactate dehydrogenase isoenzyme determinations in 6 patients showed elevated hepatic fractions. No clinical symptoms of hepatic dysfunction were seen.
