ABBOTT ZYFLO (ZILEUTON) LABELING RECOMMENDS AT LEAST SEVEN LIVER MONITORING TESTS IN FIRST YEAR ON ASTHMA THERAPY; LEUKOTRIENE ANTAGONIST CLEARS AGENCY DEC. 9

Executive Summary

Abbott's leukotriene antagonist Zyflo labeling recommends a minimum of seven liver monitoring tests during the first year of therapy. Labeling advises that "hepatic transaminases be evaluated at initiation of, and during therapy with, Zyflo" and that serum ALT -- the most sensitive indicator of liver injury -- "be monitored before treatment begins, once-a-month for the first three months, every two to three months for the remainder of the first year, and periodically thereafter." FDA approved Zyflo (zileuton) for asthma on Dec. 9.