Antagonisation of fentanyl-induced respiratory depression by nalbuphine

The opioid antagonistic efficacy of nalbuphine (20 mg i.v.) was determined in 11 healthy volunteers, who had received 10 micrograms/kg fentanyl ten minutes before. The mean respiratory minute volume decreased to 31.5% of baseline level after fentanyl and increased to 116.8% 2 min. after the administration of nalbuphine. PaCO2, PaO2 and pH values showed the typical clinical signs of respiratory depression and reached pre-fentanyl levels following nalbuphine. No significant hemodynamic changes were caused by the antagonisation. These results suggest that nalbuphine effectively and safely reverses the respiratory depressant effects of commonly used doses of fentanyl without causing hemodynamic side effects.