Effects of gabapentin on postoperative morphine consumption and pain after abdominal hysterectomy: A randomized, double-blind trial

• Published in: Acta anaesthesiologica Scandinavica Vol. 48; no. 3; pp. 322 - 327
• Main Authors: Dierking, G., Duedahl, T. H., Rasmussen, M. L., Fomsgaard, J. S., MØiniche, S., RØmsing, J., Dahl, J. B.
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden , USA Munksgaard International Publishers 01.03.2004; Blackwell
• Subjects: Acetates - blood; Acetates - therapeutic use; Adult; Aged; Amines; Analgesia, Patient-Controlled; Analgesics - blood; Analgesics - therapeutic use; Analgesics, Opioid - administration & dosage; Analgesics, Opioid - therapeutic use; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Cyclohexanecarboxylic Acids; Dizziness - etiology; Double-Blind Method; Female; Follow-Up Studies; Gabapentin; gamma-Aminobutyric Acid; Humans; hyperalgesia; Hysterectomy - adverse effects; Medical sciences; Middle Aged; Morphine - administration & dosage; Morphine - therapeutic use; pain; Pain Measurement; Pain, Postoperative - prevention & control; Placebos; postoperative; Postoperative Nausea and Vomiting - etiology; Premedication; Sleep Stages - drug effects; Treatment Outcome; Postoperative; pain; postoperative; Gabapentin; hyperalgesia; Pain; Gabapentin; Anesthesia; Morphine; Hysterectomy
• ISSN: 0001-5172; 1399-6576
• DOI: 10.1111/j.0001-5172.2004.0329.x

Background:  Preliminary clinical studies have suggested that gabapentin may produce analgesia and reduce the need for opioids in postoperative patients. The aim of the present study was to investigate the opioid‐sparing and analgesic effects of gabapentin administered during the first 24 h after abdominal hysterectomy. Methods:  In a randomized, double‐blind study, 80 patients received oral gabapentin 1200 mg or placebo 1 h before surgery, followed by oral gabapentin 600 mg or placebo 8, 16 and 24 h after the initial dose. Patients received patient‐controlled analgesia with morphine at doses of 2.5 mg with a lock‐out time of 10 min for 24 h postoperatively. Pain was assessed on a visual analogue scale (VAS) at rest and during mobilization, nausea, somnolence and dizziness on a four‐point verbal scale, and vomiting as present/not present at 2, 4, 22 and 24 h postoperatively. Results:  Thirty‐nine patients in the gabapentin group, and 32 patients in the placebo group completed the study. Gabapentin reduced total morphine consumption from median 63 (interquartile range 53–88) mg to 43 (28–60) mg (P < 0.001). We observed a significant inverse association between plasma levels of gabapentin at 2 h postoperatively, and morphine usage from 0 to 2 h, and from 0 to 4 h postoperatively (R2 = 0.30, P = 0.003 and R2 = 0.24 P = 0.008, respectively). No significant differences in pain at rest or during mobilization, or in side‐effects, were observed between groups. Conclusion:  Gabapentin in a total dose of 3000 mg, administered before and during the first 24 h after abdominal hysterectomy, reduced morphine consumption with 32%, without significant effects on pain scores. No significant differences in side‐effects were observed between study‐groups.