The Effect of Gabapentin Premedication on Postoperative Nausea, Vomiting, and Pain in Patients on Preoperative Dexamethasone Undergoing Craniotomy for Intracranial Tumors

Background: In patients undergoing craniotomy, the incidence of postoperative nausea and vomiting (PONV) is 55% to 70% and that of moderate to severe postoperative pain is 60% to 84%. We hypothesized that gabapentin plus dexamethasone would be superior, compared with placebo and dexamethasone in reducing the incidences of PONV and pain after craniotomy.

Methods: Patients undergoing craniotomy received either placebo (group D) or gabapentin (600 mg) (group GD) premedication orally, 2 hours before induction of anesthesia. In addition, all patients received 4 mg of intravenous dexamethasone on the morning of surgery and continued receiving it after every 8 hours. The 24-hour incidence of nausea, emesis, or PONV (nausea, emesis, or both) (primary outcome) and postoperative pain scores (secondary outcome) were analyzed with the χ test and the Wilcoxon rank-sum test as applicable.

Results: A significant difference was observed between the groups in the incidence of nausea (odds ratio [OR], 0.23; 95% confidence interval [CI], 0.07, 0.80; P=0.02), PONV (OR, 0.3; 95% CI, 0.08, 0.8; P=0.02), and the requirement for antiemetics (OR, 0.30; 95% CI, 0.09, 0.9; P=0.03). The number of emetic episodes were also reduced in group GD, but this did not assume statistical significance (OR, 0.34; 95% CI, 0.10, 1.1; P=0.06). However, there was no significant difference in either the postoperative pain scores or the opioid consumption between the 2 groups.

Conclusions: A dosage of 600 mg of gabapentin plus 4 mg of dexamethasone significantly reduced the 24-hour incidence of nausea and PONV. However, there was no reduction in either the postoperative pain scores or opioid consumption.