Antibody-bound nalorphine released on challenge with morphine

Abstract

IN mice treated with morphine coupled to bovine serum albumin (BSA), antibodies are formed which bind injected morphine and reduce its analgesic effect¹. The possible therapeutic implications of this observation have been speculated on², but a calculation of the number of morphine-binding ligands of a satisfactory antibody titre gives a theoretical binding capacity of only about 15 mg morphine in an adult human. The immunological removal of such low amounts of morphine would be of little practical value in the treatment of high dose intravenous abusers of opiates. One way to improve the effectiveness of the antimorphine principle is to transfer passive immunity³. Another way, which is described here, is the generation of an antibody-bound store of a morphine antagonist which can be released by displacement from the binding sites into an active form when morphine is injected.