The effect of mepyramine on the development of morphine tolerance and physical dependence in mice

Abstract

The H 1 receptor antagonist mepyramine (Anthisan) has been studied for its effects on the development of morphine tolerance and physical dependence in mice. When administered during the ‘induction phase’, mepyramine was found to inhibit the development of physical dependence, but not of tolerance. These results provide preliminary circumstantial evidence for the implication of histamine in the mechanisms of morphine physical dependence in mice. Brain histamine levels were increased 24 hr after treatment with mepyramine.