Relative potencies and durations of action with respect to respiratory depression of intravenous meperidine, fentanyl and alphaprodine in man.

Fentanyl, 0.7 and 1.4 microgram/kg, alphaprodine, 0.

Effect of hypercapnia on hypoxic ventilatory drive in carotid body-resected man.

Steplike end-tidal hypoxic drives (PETCO2 = 53 Torr) lasting for 5 min were generated in a group of normal subjects and a group of carotid body-resected subjects when end-tidal CO2 was maintained constant under eucapnic (PETCO2 = 39 Torr) and hypercapnic (PETCO2 = 49 Torr) conditions. The hypoxic ventilatory response of the normal subjects was prompt and significant in eucapnia and was enhanced in the hypercapnic state, evidencing CO2-O2 interaction. In contrast, the carotid body-resected subjects did not respond to eucapnic hypoxia but did demonstrate a small but significant ventilatory response to hypoxia against the hypercapnic background.

Tolerance to the respiratory effects of marijuana in man.

The respiratory depressant effect of marijuana was studied by means of carbon dioxide respiratory response curves in eight healthy male subjects participating in a study of the effects of a 90-day ad libitum intoxication to marijuana. Subjects were studied in the morning after refraining from marijuana use since the previous evening. Respiratory response curves were done before smoking and at 15, 30 and 60 minutes after smoking two 900-mg cigarettes containing 2.