Analgesic efficacy of i.m. alfentanil.
We have studied the analgesic, respiratory, cardiovascular and sedative effects of alfentanil 30 micrograms kg-1 i.m. in two experiments in six healthy volunteers. In the first experiment, recordings were made up to 120 min after injection. Thresholds (sensory and pain) and pain-related evoked potentials (amplitude and latency) to cutaneous argon laser stimulation were used for quantitative assessment of onset, efficacy and duration of analgesia. Pain was significantly reduced from 5 to 60 min after injection. The onset phase of analgesia was faster than the recovery phase. In the second experiment, the alfentanil-induced analgesia was antagonized by naloxone 0.4 mg i.v. The reaction time to pain was prolonged significantly 15 min after injection, whereas the latency of the pain-related potential remained constant. No clinically significant changes were observed in respiratory and cardiovascular measurements.
Arendt-Nielsen
L
L
Department of Medical Informatics, Aalborg University, Denmark.
Oberg
B
B
Bjerring
P
P
D000328:Adult; D015760:Alfentanil / Q000008:administration & dosage / Q000037:antagonists & inhibitors; D000698:Analgesia; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D010147:Pain Measurement; D011930:Reaction Time; D012684:Sensory Thresholds / Q000187:drug effects; D013997:Time Factors
D015760:Alfentanil; D009270:Naloxone