139
document
Behavioral and physiological effects of remifentanil and alfentanil in healthy volunteers . BACKGROUND The subjective and psychomotor effects of remifentanil have not been evaluated . Accordingly , the authors used mood inventories and psychomotor tests to characterize the effects of remifentanil in healthy , non-drug-abusing volunteers . Alfentanil was used as a comparator drug . METHODS Ten healthy volunteers were enrolled in a randomized , double-blinded , placebo-controlled , crossover trial in which they received an infusion of saline , remifentanil , or alfentanil for 120 min . The age- and weight-adjusted infusions ( determined with STANPUMP , a computer modeling software package ) were given to achieve three predicted constant plasma levels for 40 min each of remifentanil ( 0.75 , 1.5 , and 3 ng/ml ) and alfentanil ( 16 , 32 , and 64 ng/ml ) . Mood forms and psychomotor tests were completed , and miosis was assessed , during and after the infusions . In addition , analgesia was tested at each dose level using a cold-pressor test . RESULTS Remifentanil had prototypic micro-like opioid subjective effects , impaired psychomotor performance , and produced analgesia . Alfentanil at the dose range tested had more mild effects on these measures , and the analgesia data indicated that a 40:1 potency ratio , rather than the 20:1 ratio we used , may exist between remifentanil and alfentanil . A psychomotor test administered 60 min after the remifentanil infusion was discontinued showed that the volunteers were still impaired , although they reported feeling no drug effects . CONCLUSIONS The notion that the pharmacodynamic effects of remifentanil are extremely short-lived after the drug is no longer administered must be questioned given our findings that psychomotor effects were still apparent 1 h after the infusion was discontinued .
140
Intervention_Pharmacological
remifentanil
141
Intervention_Pharmacological
alfentanil
142
Intervention_Pharmacological
remifentanil
143
Intervention_Pharmacological
remifentanil
144
Intervention_Control
placebo-controlled
145
Intervention_Pharmacological
saline
146
Intervention_Pharmacological
remifentanil
147
Intervention_Pharmacological
alfentanil
148
Intervention_Pharmacological
STANPUMP
149
Intervention_Pharmacological
computer modeling software package
150
Intervention_Pharmacological
remifentanil
151
Intervention_Pharmacological
Remifentanil
152
Intervention_Pharmacological
remifentanil
153
Outcome_Mental
Behavioral and physiological effects
154
Outcome_Mental
subjective and psychomotor effects
155
Outcome_Mental
prototypic micro-like opioid subjective effects , impaired psychomotor performance , and produced analgesia
156
Outcome_Physical
analgesia
157
Outcome_Mental
pharmacodynamic effects
158
Outcome_Mental
psychomotor effects
159
Participant_Condition
healthy
160
Participant_Condition
non-drug-abusing
161
Participant_Sample-size
Ten