title: Nicotine for postoperative analgesia: a systematic review and meta-analysis.
abstract: BACKGROUND
  The perioperative adminstration of nicotine has been investigated as an analgesic adjunct and a possible modality to prevent postoperative nausea and vomiting (PONV). We performed this systematic review to assess the impact of perioperative administration of nicotine on postoperative pain and PONV.
  
  
  METHODS
  A literature search of MEDLINE, CENTRAL, EMBASE, and CINAHL was done for randomized controlled trials that investigated the effects of nicotine compared with placebo regarding postoperative pain and/or PONV in patients undergoing surgery under general anesthesia. A random effects model was used for analysis. The primary end points were cumulative analgesic consumption and pain scores at 24 hours after surgery.
  
  
  RESULTS
  Nine studies (662 patients) were included. Nicotine was administered as a transdermal patch in 6 studies and as a nasal spray in 3. Four studies recruited only women while 7 recruited only nonsmokers. Perioperative nicotine administration was associated with a reduction in cumulative opioid consumption at 24 hours compared with control (mean difference = -4.85 mg morphine equivalents, 95% confidence interval [CI], = -9.40 to -0.30, P = 0.04). Pain scores were neither clinically nor statistically reduced. Nicotine was associated with a significantly higher incidence of postoperative nausea (relative risk = 1.26, 95% CI, = 1.05 to 1.52) and need for rescue antiemetics (relative risk = 1.54, 95% CI, = 1.37 to 1.74) during the first postoperative hour and significantly higher postoperative nausea at 24 hours (relative risk = 1.14, 95% CI, = 1.02 to 1.28). The 24 hours opioid sparing was only seen in nonsmokers. When excluding 1 study with high risk of bias, nicotine was still associated with more postoperative nausea at 24 hours (relative risk = 1.15, 95% CI, = 1.05 to 1.25).
  
  
  CONCLUSIONS
  This systematic review suggests that perioperative nicotine administration was associated with a statistically significant reduction in cumulative opioid consumption at 24 hours and a statistically insignificant reduction in pain scores at 24 hours. Perioperative nicotine was also associated with an increased incidence of postoperative nausea in patients undergoing surgery under general anesthesia. The opioid-sparing effect seemed to be limited to nonsmokers. Current data do not support a role for nicotine in perioperative analgesia.
authors.affiliation: From the Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Basem M
authors.initials: BM
authors.lastname: Mishriky
authors.forename: Ashraf S
authors.initials: AS
authors.lastname: Habib
mesh_terms: D000279:Administration, Cutaneous; D000281:Administration, Intranasal; D000336:Aerosols; D000700:Analgesics / Q000008:administration & dosage* / Q000009:adverse effects; D000701:Analgesics, Opioid / Q000627:therapeutic use; D004334:Drug Administration Schedule; D006801:Humans; D007902:Length of Stay; D009538:Nicotine / Q000008:administration & dosage* / Q000009:adverse effects; D018722:Nicotinic Agonists / Q000008:administration & dosage* / Q000009:adverse effects; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000517:prevention & control*; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced; D012307:Risk Factors; D013997:Time Factors; D057968:Transdermal Patch; D016896:Treatment Outcome
chemical_list: D000336:Aerosols; D000700:Analgesics; D000701:Analgesics, Opioid; D018722:Nicotinic Agonists; D009538:Nicotine