after premedication with morphine and scopolamine , patients received either fentanyl , 100 micrograms/kg ( n = 16 ) , or sufentanil , 15 micrograms/kg , ( n = 17 ) , intravenously ( iv ) , over 10 minutes to induce anesthesia .
C0015846
fentanyl
C0143993
sufentanil