Printed in U.S.A. THE MAGNITUDE AND DURATION OF RESPIRATORY DEPRESSION DUE TO FENTANYL AND

DOWNES, JOHN J., RICHARD A. KEu AND C. J. LAMBERTSEN: The magnitude and duration of respiratory depression due to fentanyl and meperidine in man. J. Pharmacol. Exp. Therap. 158: 416-420, 1967. The effect of the potent analgesic, fentanyl, on minute volume, tidal volume and respiratory frequency at a controlled alveolar carbon dioxide tension of 46 mm Hg in six normal adult men was determined at intervals over a 4-hr period. Fentanyl was administered i.m. in two doses (0.1 mg and 02 mg) and the effects were compared with those of i.m. physiologic saline (2.0 ml) and meperidine hydrochloride (75 mg), all on the basis of 70 kg of body weight. In the doses employed (fentanyl, 0.1 mg; meperidine, 75 mg), the magnitude of maximal depression of the two narcotics is similar. Thus, in equi-analgesic doses (fentanyl, 0.1 mg; meperidine, 65 mg) maximal ventilatory depression with fentanyl would be slightly greater. However, the onset and peak depression of minute ventilation, as well as the recovery toward control levels, occurs more rapidly with fentanyl. Thus, fentanyl may be a useful narcotic agent when rapid onset and recovery from the effects of the analgesic are desired