THOSE impatient of medicines not acting fast enough should try grape-juice. Researchers from the University of Michigan Medical Center (UM-C) have isolated a pair of substances in grapefruit juice that helps the gut absorb drugs readily. While earlier studies did suggest the connection, nobody knew how it happened. With the new findings, published in the November issue of the journal Drug Metabolism and Disposition, scientists theorise the two substances in grapefruit act like suicide bombers by destroying certain enzymes in the small intestine that interfere with drug absorption.