Heparin-induced transaminase elevations: a prospective study.

An intensive and prospective surveillance study of 54 patients hospitalized in the Internal Medicine Unit of Clinical Hospital of the Catholic University of Chile, who required heparin in the period between June and December of 1991 was done. The aim of the work was to characterize and study the incidence of the adverse reactions associated with heparin therapy, with special emphasis on abnormal serum transaminase elevation. Abnormal transaminase elevation was defined as a rise over 20% of the serum transaminase baseline value. For determining the serum transaminase level, a UV spectrophotometric method was used. The incidence of the adverse drug reactions (ADR) was 24.1% (13 ADR), 8 of which (14.8%) were related with heparin therapy. Three of them (5.5%) corresponded to alanine transaminase (ALAT) increase and five (9.3%) to aspartate transaminase (ASAT) elevation. By means of global introspection method, 3 cases of ALAT increases were defined as probable and 6 as possible, while 5 ASAT increases were estimated as probable and 14 as possible. All of them were of slow onset, did not require treatment and hospital stay was not prolonged. Two patients' characteristics--age and sex--were associated with the development of heparin-induced abnormal alanine transaminase concentrations. The younger male patients showed a greater frequency of heparin-induced ALAT elevation. However, this association was not observed with the heparin-induced ASAT increase. These reactions were dose-dependent. Patients with heparin-induced ALAT elevation received a dose of 154,220 IU +/- 72,970 IU in comparison to patients without that adverse reaction who received 96,210 IU +/- 40,340 IU. This difference was statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)