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Comparative analgesic and mental effects of increasing plasma concentrations of dexmedetomidine and alfentanil in humans.
- Source :
-
Anesthesiology [Anesthesiology] 2004 Sep; Vol. 101 (3), pp. 744-52. - Publication Year :
- 2004
-
Abstract
- Background: In animals, systemic and intrathecal administration of the alpha2 -adrenergic receptor agonist dexmedetomidine results in robust antinociceptive effects in models of heat pain. In humans, systemically administered dexmedetomidine is approved for sedating patients in the intensive care unit. However, whether systemic administration of dexmedetomidine in humans produces significant analgesia at doses causing sedation but not unconsciousness remains controversial.<br />Methods: This study in human volunteers used a placebo-controlled, double-blind, and randomized design to examine whether dexmedetomidine at doses causing mild to severe sedation produces analgesia in experimental models of heat and electrical pain. Results were compared to the effects of the mu-opioid receptor agonist alfentanil. A computer-controlled infusion provided four median step-up plasma concentrations of dexmedetomidine (0.09, 0.24, 0.54, and 1.23 ng/ml) and alfentanil (13.4, 33.8, 67.8, and 126.1 ng/ml).<br />Results: Sedative and cognitive effects of dexmedetomidine were dose-dependent, resulting in a median sedation score of 95 of 100 and slowing of cognitive speed (reaction time, trail-making test) by a factor of about two at the highest plasma concentration. Dexmedetomidine did not attenuate heat or electrical pain. Alfentanil caused severe sedation (median sedation score 88 of 100) and slowed cognitive speed by a factor of approximately 1.4 at the highest plasma concentration. Alfentanil attenuated heat and electrical pain dose dependently.<br />Conclusion: This study documents that systemic dexmedetomidine lacks analgesic efficacy for heat and electrical pain at doses causing mild to severe sedation. These results provide further evidence suggesting that systemic administration of dexmedetomidine lacks broad analgesic activity in models of acute pain at doses not rendering humans unconscious.
- Subjects :
- Adult
Dose-Response Relationship, Drug
Double-Blind Method
Electric Stimulation
Female
Gas Chromatography-Mass Spectrometry
Hemodynamics drug effects
Hot Temperature
Humans
Hypnotics and Sedatives pharmacology
Infusions, Intravenous
Male
Neuropsychological Tests
Pain Measurement drug effects
Reaction Time drug effects
Adrenergic alpha-Agonists blood
Adrenergic alpha-Agonists pharmacology
Alfentanil blood
Alfentanil pharmacology
Analgesics, Non-Narcotic blood
Analgesics, Non-Narcotic pharmacology
Analgesics, Opioid blood
Analgesics, Opioid pharmacology
Dexmedetomidine blood
Dexmedetomidine pharmacology
Mental Processes drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0003-3022
- Volume :
- 101
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Anesthesiology
- Publication Type :
- Academic Journal
- Accession number :
- 15329600
- Full Text :
- https://doi.org/10.1097/00000542-200409000-00024