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Three Part Question

In [adult patients] is [gabapentin effective] in [reducing opioid consumption postoperatively]?

Clinical Scenario

Is Gabapentin effective as an adjuant in reducing postoperative pain and opioid requirement?

Search Strategy

Allied & Complementary Medicine - 1985 to date (AMED)
British Nursing Index - 1994 to date (BNID)
CINAHL (R) - 1982 to date (NAHL)
DH-DATA - 1983 to date (DHSS)
EMBASE - 1974 to date (EMZZ)
EMBASE - 1996 to date (EMED)
King's Fund - 1979 to date (KFND)
MEDLINE - 1951 to date (MEZZ)
MEDLINE - 1996 to date (MEDL)
PsycINFO - 1806 to date (PSYC)
Gabapentin AND postoperative ADJ analgesia

Search Outcome

10/13 papers good quality

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
A. Turan at al Feb 2006 Turkey	40 patients undergoing lower extremity surgery procedures	40 patients undergoing lower extremity surgery procedures were randomly assigned to receive (i) placebo capsules (control) or (ii) gabapentin (1.2 g day–1) before and for 2 days after surgery.	verbal rating scale scoring for pain and sedation, PCEA usage, quality of recovery assessment, times of GI function recovery, and patient satisfaction scoring for pain management	Pain scores at 1, 4, 8, 12, and 16 h (P<0.001), PCEA bolus requirements (n) at 24 and 72 (P<0.05) and paracetamol (mg) consumption; P<0.05), were significantly lower in the gabapentin-treated patients than in the control group. Patient satisfaction was better in gabapentin-treated patients. Gabapentin-treated patients had less motor block when compared with control group. Times of return of bowel function, hospitalization, and resumption of dietary intake were similar in the groups. However, the incidence of dizziness was higher in the gabapentin group (35% vs 5%; P<0.05).
Ménigaux et al, May 2005 France	arthroscopic anterior cruciate ligament repair; 40 patients	40 patients were randomly assigned to receive 1200 mg oral gabapentin or placebo 1–2 h before surgery;PCA morphine for postop pain relief	Pain scores and morphine consumption were recorded over 48 h. Degrees of active and passive knee flexion and extension were recorded during physiotherapy on days 1 and 2.	Preoperative anxiety scores were less in the gabapentin than control group (visual analog scale scores of 28 ± 16 mm versus 66 ± 15 mm, respectively; P < 0.001). The gabapentin group required less morphine than the control group (29 ± 22 mg versus 69 ± 40 mg, respectively; P < 0.001). Visual analog scale pain scores at rest and after mobilization were significantly reduced in the gabapentin group. First and maximal passive and active knee flexions at 24 and 48 h were significantly more extensive in the gabapentin than in the control group
Dirks et al, September 2002 Denmark	Radical mastectomy; 70 patients	Radical mastectomy; 70 patients received a single dose of oral gabapentin (1,200 mg) or placebo 1 h before surgery; PCA morphine for postop pain relief	Pain relief(VAS),opioid consumption	A single dose of 1,200 mg oral gabapentin resulted in a substantial reduction in postoperative morphine consumption and movement-related pain after radical mastectomy, without significant side effects
Dierking et al, 2004 Mar Denmark	80 patients ,abdominal hysterectomy	80 patients received oral gabapentin 1200 mg or placebo 1 h before surgery(abdominal hysterectomy), followed by oral gabapentin 600 mg or placebo 8, 16 and 24 h after the initial dose, PCA for postop pain	Pain relief(VAS), nausea, somnolence and dizziness on a four-point verbal scale, and vomiting	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
Rorarius et al, 2004 Jul Finland	elective vaginal hysterectomy	1200 mg of gabapentin or 15 mg of oxazepam (active placebo) 2.5 h prior to induction of anaesthesia to patients undergoing elective vaginal hysterectomy	Pain scores, opioid consumption, side effects	Gabapentin reduced the need for additional postoperative pain treatment (PCA boluses of 50 microg of fentanyl) by 40% during the first 20 postoperative hours. During the first 2 postoperative hours pain scores at rest and worst pain score (VAS 0-100 mm) were significantly higher in the active placebo group compared to the gabapentin-treated patients. Additionally, pretreatment with gabapentin reduced the degree of postoperative nausea and incidence of vomiting/retching possibly either due to the diminished need for postoperative pain treatment with opioids or because of an anti-emetic effect of gabapentin itself. No preoperative differences between the two groups were encountered with respect to the side effects of the premedication
Radhakrishnan et al, July 2005 India	lumbar laminectomy and discectomy; 60 adult patients	lumbar laminectomy and discectomy; gabapentin 800 mg (in two equally divided doses) or placebo was given preoperatively to 60 adult patients; PCA morphine	Pain at rest and on movement was assessed using a Verbal Rating Scale (VRS) every 2 hours for the first 8 postoperative hours	Gabapentin does not decrease the morphine requirement or morphine side effects in the immediate postoperative period following lumbar laminectomy and discectomy.
Pandey et al, April 2005 India	100 patients for lumbar discectomy	100 patients were divided into five groups to receive placebo or gabapentin 300, 600, 900, or 1200 mg 2 hours before lumbar diskectomy. After surgery, patients were transferred to the postanesthesia care unit (PACU). A blinded anesthesiologist recorded the pain scores at time points of 6, 12, 18, and 24 hours in the PACU on a Visual Analog Scale (VAS; 0-10 cm) at rest. Patients received patient-controlled analgesia (fentanyl 1.0 [mu]g/kg on each demand with lockout interval of 10 minutes); total fentanyl consumption during initial 24 hours was recorded	Pain scores, opioid consumption	gabapentin 600 mg is the optimal dose for postoperative pain relief following lumbar diskectomy
Chandra Kant Pandey et al, April 2004 India	459 patients, laparoscopic cholecystectomy	459 ASA I and II patients were randomly assigned to receive 300 mg gabapentin, 100 mg tramadol or placebo in a double-blind manner two hours before laparoscopic cholecystectomy under general anesthesia. Patients received fentanyl 2 micro g*kg(-1) intravenously on demand.	Pain relief(VAS), opioid consumption	Patients in the gabapentin group had significantly lower pain scores at all time intervals in comparison to tramadol and placebo. Significantly less fentanyl was consumed in the gabapentin group than in the tramadol and placebo groups. Sedation (33.98%), nausea/retching/vomiting (24.8%) were the commonest side effects in the gabapentin group whereas respiratory depression (3.9%) was the commonest in the tramadol group and vertigo (7.8%) in the placebo group.
Turan et al, Jan 2006 Turkey	100 patients undergoing abdominal hysterectomy	100 patients undergoing abdominal hysterectomy procedures were randomly assigned to one of four treatment groups: 1) control group received placebo capsules and pills before and for 2 days after surgery, 2) rofecoxib group received 50 mg/d PO and placebo capsules before and after surgery and, 3) gabapentin group received 1.2 g/d PO and placebo pills before and after surgery, and 4) combination group received rofecoxib 50 mg/d and gabapentin 1.2 g/d PO before and after surgery	Recovery,Pain relief, opioid consumption, sedation, recovery of bowel function	Gabapentin (1.2 g/d PO) appears to be an acceptable alternative to rofecoxib (50 mg/d PO) for short-term use as an adjuvant to opioid analgesics in patients undergoing lower abdominal surgery

Comment(s)

Though the numbers were small(maximum number in one study was 459, others less than 100), gabapentin reduces opioid consumption significantly

Clinical Bottom Line

All these preliminary studies except one found gabapentin to be effective adjuant for pain relief for adult patients

References

1. A. Turan at al Effect of oral gabapentin on postoperative epidural analgesia British Journal of Anaesthesia Feb 2006, Volume 96, Number 2 Pp. 242-246
2. Ménigaux, Christophe; Adam, Frédéric; Guignard, Bruno et al. Preoperative Gabapentin Decreases Anxiety and Improves Early Functional Recovery from Knee Surgery Anesthesia and Analgesia Volume 100(5), May 2005, pp 1394-1399
3. Dirks, Jesper; Fredensborg, Birgitte; Christensen, Dennis et al. A Randomized Study of the Effects of Single-dose Gabapentin versus Placebo on Postoperative Pain and Morphine Consumption after Mastectomy Lippincott, Williams and Wilkins Volume 97(3), September 2002, pp 560-564
4. Dierking G, Duedahl TH, Rasmussen ML et al. Effects of gabapentin on postoperative morphine consumption and pain after abdominal hysterectomy: a randomized, double-blind trial. Blackwell-synergy Acta Anaesthesiol Scand. 2004 Mar;48(3):322-7.
5. Rorarius MG, Mennander S, Suominen P et al. Gabapentin for the prevention of postoperative pain after vaginal hysterectomy Elsevier Science Pain. 2004 Jul;110(1-2):175-81.
6. Radhakrishnan, M, Bithal, Parmod K et al. Effect of Preemptive Gabapentin on Postoperative Pain Relief and Morphine Consumption Following Lumbar Laminectomy and Discectomy: A Randomized, Double-Blinded, Placebo-Controlled Study Lippincott Williams & Wilkins, Inc. Journal of Neurosurg Anesthesiology, Volume 17(3), July 2005, pp 125-128
7. Pandey, Chandra Kant, Navkar et al. Evaluation of the Optimal Preemptive Dose of Gabapentin for Postoperative Pain Relief After Lumbar Diskectomy: A Randomized, Double-Blind, Placebo-Controlled Study Lippincott Williams & Wilkins, Inc Journal of Neurosurg Anesthesiiology, Volume 17(2), April 2005, pp 65-68
8. Chandra Kant Pandey, Shio Priye, Surendra Singh et al. Preemptive use of gabapentin significantly decreases postoperative pain and rescue analgesic requirements in laparoscopic cholecystectomy Canadian Anesthesiologists' Society Canadian Journal of Anesthesia 51:358-363 (2004)
9. Turan, A, White, P F, Karamanlioglu, B et al. Gabapentin: An Alternative to the Cyclooxygenase-2 Inhibitors for Perioperative Pain Management International Anesthesia Research Society, LWW Anesthesia and Analgesia, Volume 102(1), January 2006, pp 175-181