A sex difference in the effects of oral codeine and promethazine on the ventilatory response to carbon dioxide in human volunteers

Br J Clin Pharmacol. 1980 Feb;9(2):159-64. doi: 10.1111/j.1365-2125.1980.tb05827.x.


1 Interactions between codeine and promethazine have been studied in male and female volunteers, measuring ventilation, end tidal PCO2, ventilatory response to CO2, pulse and blood pressure. 2 The effects of codeine on the above measurements have been compared in subjects who habitually smoke cigarettes and non smoking subjects. 3 Codeine displaced the ventilatory response to CO2 to the right and increased end tidal PCO2 in female subjects but not in males. 4 Promethazine plus codeine displaced the ventilatory response to CO2 to the right in male subjects but tended to reduce the response to codeine in females. 5 The slope of the ventilatory response to CO2 was significantly steeper in smokers and codeine caused significant reductions in slope in these subjects.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Blood Pressure / drug effects
  • Carbon Dioxide / pharmacology
  • Codeine / pharmacology*
  • Female
  • Heart Rate / drug effects
  • Humans
  • Male
  • Middle Aged
  • Promethazine / pharmacology*
  • Respiration / drug effects*
  • Sex Factors
  • Smoking / metabolism


  • Carbon Dioxide
  • Promethazine
  • Codeine