Effects of oral narcotics on sleep-disordered breathing in healthy adults

Alcohol and benzodiazepines may increase sleep-disordered breathing by decreasing activity of pharyngeal dilating muscles, favoring the development of obstructive apneas and hypopneas. Narcotics cause greater depression of wakeful respiration than the previously mentioned drugs; however, the influence of narcotics on the upper airway and breathing during sleep has not been studied. We, therefore, examined, in 12 healthy adults, the effects of oral hydromorphone hydrochloride (2 and 4 mg) on breathing during sleep and on a variety of awake respiratory variables (minute ventilation, gas exchange, and chemoresponsiveness). In addition, awake pharyngeal inspiratory airflow resistance was determined before and after narcotic administration to assess the drug's influence on patency of the upper airway. Following both doses, minute ventilation decreased, and carbon dioxide pressure increased. The 4-mg dose of hydromorphone hydrochloride also produced a significant decrement in the hypoxic ventilatory response, whereas hypercapnic responsiveness and pharyngeal resistance did not change following either dose of the drug. Despite the respiratory depression during wakefulness described previously, no significant change was observed in any measure of sleep-disordered breathing after either dose of narcotic. We conclude that in healthy individuals without suspected sleep apnea, oral hydromorphone in standard dosages does not significantly increase sleep-disordered breathing. This result may be due to a lack of selective depression of upper-airway muscular function by the doses of narcotic used.