Intoxication and other subjective effects of preanesthetic opioids in surgical patients: A randomized controlled trial
7 affiliations
- 1Department of Psychology, University of Oslo, Oslo, Norway
- 2Department of Anesthesiology, Kongsberg Hospital, Vestre Viken Hospital Trust, Kongsberg, Norway
- 3Center for Integrative and Complementary Medicine, Division of Anesthesiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- 4Department of Research and Development, Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway
- 5Department of Anesthesiology and Intensive Care Medicine, Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway
- 6Department of Psychiatry and Sanford Institute for Empathy and Compassion, University of California, San Diego, San Diego, CA, USA
- 7Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
Abstract
Opioids are often administered before anesthesia to reduce stress/discomfort or enhance well-being, despite limited supporting evidence. This double-blind, randomized controlled trial investigates the acute subjective effects of intravenous morphine (10 mg), oxycodone (5 mg), and fentanyl (0.1 mg) in 199 adults undergoing elective surgery (ASA physical status I–II). All patients received a standardized multimodal preoperative medication. Patients rated their experiences on 0–10 verbal numerical rating scales immediately before and 3 min after opioid administration. The most prominent drug effects were undesirable (intoxication, sedation, and dizziness). Fentanyl produced higher ratings of intoxication, sedation, dizziness, and euphoria than morphine, with oxycodone generally showing intermediate effects. Substantial interindividual variability was observed across all treatment groups. Desirable effects (reduced anxiety and increased relaxation) were modest, and only 23% of patients reported feeling better. Notably, 96% reported feeling intoxicated. These results challenge the use of preoperative opioids to improve patient comfort. EudraCT: 2020-004920-40.
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BibTeX
@article{karlsen2026intoxication,
title = {{Intoxication and other subjective effects of preanesthetic opioids in surgical patients: A randomized controlled trial}},
author = {Siri Gurandsrud Karlsen and Isabell M. Meier and Martin Trøstheim and Kaja Buen and Harald Lenz and Marlin Comelon and Silvana De Pirro and Chantal Berna and Eric L. Garland and Gernot Ernst and Siri Leknes and Marie Eikemo},
journal = {Cell Reports Medicine},
year = {2026},
month = sep,
doi = {10.1016/j.xcrm.2026.103028},
url = {https://doi.org/10.1016/j.xcrm.2026.103028},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Intoxication and other subjective effects of preanesthetic opioids in surgical patients: A randomized controlled trial
AU - Siri Gurandsrud Karlsen
AU - Isabell M. Meier
AU - Martin Trøstheim
AU - Kaja Buen
AU - Harald Lenz
AU - Marlin Comelon
AU - Silvana De Pirro
AU - Chantal Berna
AU - Eric L. Garland
AU - Gernot Ernst
AU - Siri Leknes
AU - Marie Eikemo
PY - 2026
DA - 2026/09/11
JO - Cell Reports Medicine
DO - 10.1016/j.xcrm.2026.103028
UR - https://doi.org/10.1016/j.xcrm.2026.103028
AB - Opioids are often administered before anesthesia to reduce stress/discomfort or enhance well-being, despite limited supporting evidence. This double-blind, randomized controlled trial investigates the acute subjective effects of intravenous morphine (10 mg), oxycodone (5 mg), and fentanyl (0.1 mg) in 199 adults undergoing elective surgery (ASA physical status I–II). All patients received a standardized multimodal preoperative medication. Patients rated their experiences on 0–10 verbal numerical rating scales immediately before and 3 min after opioid administration. The most prominent drug effects were undesirable (intoxication, sedation, and dizziness). Fentanyl produced higher ratings of intoxication, sedation, dizziness, and euphoria than morphine, with oxycodone generally showing intermediate effects. Substantial interindividual variability was observed across all treatment groups. Desirable effects (reduced anxiety and increased relaxation) were modest, and only 23% of patients reported feeling better. Notably, 96% reported feeling intoxicated. These results challenge the use of preoperative opioids to improve patient comfort. EudraCT: 2020-004920-40.
SN - 2666-3791
ER -