DEGREE OF TOLERANCE AND THE RELATIONSHIP BETWEEN PLASMA MORPHINE CONCENTRATION AND PUPIL DIAMETER FOLLOWING INTRAVENOUS HEROIN IN MAN

Abstract

After doses of heroin to tolerant (heroin‐dependent) persons and non‐tolerant (non‐dependent) persons, pupil diameter varies with the degree of physical dependence and the plasma concentration of the drug. The linear regression slopes of pupil diameter on plasma drug concentration correlate with daily prescription of opiates. That is, the greater the degree of physical dependence the higher the plasma drug concentration that is required for a given degree of miosis. It is suggested that these observations might provide the basis of a test to estimate the drug requirements of drug dependent patients attending treatment clinics.