Abstract

1. The pupillary size (measured photographically), rectal temperature, pulse and respiratory rates, systolic blood pressure and the incidence of nausea and vomiting were determined before and at hourly intervals after the subcutaneous administration of 20 mgm. of morphine sulfate to 20 non-addicts and 24 former addict males. Similar observations were made after the administration of a placebo to 11 former addict and 10 non-addict males.

2. Neither non-addicts nor former addicts reacted in a significant manner to a placebo.

3. Following administration of morphine, non-addicts showed a greater fall in rectal temperature than former addicts; this difference was statistically significant. After morphine the incidence of vomiting was 35 per cent in non-addicts as compared to 12.5 per cent in former addicts. Except for these differences no other evidence of residual tolerance to the effects of morphine was observed in these former addicts.