Gabapentin

Gabapentin

PEP Topic 
Acute Pain
Description 

Gabapentin, which belongs to the class of medications called anticonvulsants, treats seizures by decreasing excitement in the brain. Gabapentin has been studied for its effect in patients with cancer who have neuropathic pain or symptoms of peripheral neuropathy. The drug changes the way the body senses pain. It has also been studied for its effect on anxiety, chemotherapy-induced nausea and vomiting, and hot flashes.

Likely to Be Effective

Research Evidence Summaries

Amr, Y.M., & Yousef, A.A. (2010). Evaluation of efficacy of the perioperative administration of venlafaxine or gabapentin on acute and chronic postmastectomy pain. The Clinical Journal of Pain, 26, 381–385.

doi: 10.1097/AJP.0b013e3181cb406e
Print

Study Purpose:

To investigate the analgesic efficacy of venlafaxine and gabapentin on acute and chronic pain after breast cancer surgery

Intervention Characteristics/Basic Study Process:

Patients were randomized prior to surgery to one of three groups. The venlafaxine group received 37.5 mg of extended release venlafaxine once daily and a second placebo capsule at bedtime. The gabapentin group received 300 mg of gabapentin daily and another placebo capsule at bedtime, and the placebo group received placebo capsules daily and at bedtime. Medications were started the evening before surgery and continued for the first 10 postoperative days. Anesthesia was standardized. When patients complained of pain in recovery they were given a titrated dose of morphine until the VAS pain score was 30 or less. For the first 24 hours postoperatively, IV morphine at 20–50 mcg/kg was given to maintain Visual Analog Scale (VAS) at or below 30. For the remaining time to postoperative day 10, all patients were given acetaminophen and codeine every six hours and as necessary. Pain scores were recorded at rest and with movement at four, 12, and 24 hours on the first postoperative day, then daily for 10 days, then six months later.

Sample Characteristics:

  • N = 150 
  • FEMALES: 100%
  • KEY DISEASE CHARACTERISTICS: All had breast cancer
  • OTHER KEY SAMPLE CHARACTERISTICS: Patients had either radical or partial mastectomies with axillary dissections.

Setting:

  • SITE: Single site  
  • SETTING TYPE: Multiple settings  
  • LOCATION: Egypt

Phase of Care and Clinical Applications:

  • PHASE OF CARE: Multiple phases of care

Study Design:

Double-blinded, randomized, placebo-controlled trial

Measurement Instruments/Methods:

  • Visual Analog Scale (VAS) for pain
  • Morphine consumption

Results:

Compared to the control group, VAS scores from the second to the tenth day postoperatively were significantly lower in the gabapentin group (p < 0.0003). Compared to controls, VAS scores for pain with movement were significantly reduced for those receiving venlafaxine during days 8–10 (p < 0.0002). Total morphine consumption in the first 24 hours was lower in the gabapentin group compared to both other groups (p < 0.0001). Significantly more patients in the control and gabapentin groups were using opioids for pain at six months (p < 0.05). There were differences among groups in the type of pain reported at six months, but there were no consistent or significant differences in overall pain results. Patients who received venlafaxine had lower prevalence of burning and stabbing or pricking pain. There were no differences between groups in terms of side effects.

Conclusions:

The perioperative administration of gabapentin was associated with decreased pain during the acute phase after breast cancer surgery, but it did not appear to have an effect on the incidence of chronic pain after six months postoperatively. The administration of perioperative venlafaxine may have had a beneficial effect on chronic postmastectomy pain syndrome.

Limitations:

  • Other limitations/explanation: There was no description or analysis of differences by type of surgery, and it could be expected that individuals who had more extensive procedures could have had more acute and chronic pain.

Nursing Implications:

The findings of this study showed that perioperative gabapentin was associated with reduced pain in the acute postoperative period among women with breast cancer. The use of venlafaxine may have some benefit for long-term neuropathic pain postmastectomy, but these findings were not definitive. This adds to a growing body of evidence regarding the efficacy of gabapentin in reducing acute surgical pain and points to the need for additional research regarding interventions and the potential role of venlafaxine for postmastectomy pain syndrome.

Bala, I., Bharti, N., Chaubey, V.K., & Mandal, A.K. (2012). Efficacy of gabapentin for prevention of postoperative catheter-related bladder discomfort in patients undergoing transurethral resection of bladder tumor. Urology, 79, 853–857.

doi:10.1016/j.urology.2011.11.050
Print

Study Purpose:

To evaluate the effect of 600 mg and 1200 mg oral gabapentin pretreatment for the prevention of postoperative catheter-related bladder discomfort (CRBD) in patients undergoing catheterization after transurethral resection of bladder tumor (TURBT)

Intervention Characteristics/Basic Study Process:

Patients were randomized to three groups. Group I received four placebo capsules. Group II received two capsules of 300 mg gabapentin and two identical placebo capsules. Group III received four capsules of 300 mg gabapentin. All patients received the study drug orally, with sips of water, one hour prior to administration of anesthesia. Lumbar subarachnoid block was administered with 2.5 ml 0.5% hyperbaric bupivacaine. An anesthesiologist unaware of group assignment observed patients in the Postanesthesia Care Unit (PACU) at 1, 2, 4, 6, 12, and 24 hours.

Sample Characteristics:

  • The sample was composed of 100 patients.
  • Mean patient age was 52.2 years.
  • Of all patients, 79% were male and 21% were female.
  • All patients had been diagnosed with a bladder tumor.

Setting:

  • Single site
  • Inpatient
  • United States

 

Phase of Care and Clinical Applications:

Active antitumor treatment

Study Design:

Randomized controlled double-blind trial

Measurement Instruments/Methods:

  • Four-point scale, to record severity of bladder discomfort
  • Observations of postoperative nausea, vomiting, and any adverse effect (e.g., sedation, dizziness, ataxia, tinnitus, diplopia, vertigo) related to the study drug

Results:

  • At 1, 2, and 24 hours after surgery, patients in group II, who received 600 mg gabapentin, had significantly lower incidence of CRBD (p < 0.0001) than did patients in the control group (group I).
  • At all time points, the incidence of CRBD was significantly lower (p < 0.0001) in patients receiving 1200 mg gabapentin (group III) than in the control group (group I).
  • At 4, 6, 12, and 24 hours, the incidence of CRBD was significantly lower (p < 0.0001) in patients receiving 1200 mg gabapentin (group III) than in group II.
  • Compared to the severity of CRBD in group I, the severity of CRBD was significantly lower (p < 0.0001) in groups II and III.

Conclusions:

Pretreatment with gabapentin reduces bladder discomfort in patients with an indwelling postoperative catheter. Gabapentin 1200 mg is more effective than gabapentin 600 mg in decreasing the incidence and severity of CRBD.

Limitations:

  • The study had risk of bias due to sample characteristics. The sample was primarily male, though the male-to-female ratio was similar in all three groups.
  • Findings are not generalizable.

Nursing Implications:

To decrease the postoperative discomfort of patients undergoing catheterization after transurethral resection of bladder tumor, nurses may want to advocate for the preoperative use of 1200 mg gabapentin.

Bharti, N., Bala, I., Narayan, V., & Singh, G. (2013). Effect of gabapentin pretreatment on propofol consumption, hemodynamic variables, and postoperative pain relief in breast cancer surgery. Acta Anaesthesiologica Taiwanica, 51, 10–13.

doi: 10.1016/j.aat.2013.03.009
Print

Study Purpose:

To evaluate the effects of preoperative gabapentin on anesthesia requirements and postoperative pain

Intervention Characteristics/Basic Study Process:

Patients were randomized to receive either 600 mg gabapentin or placebo two hours prior to surgery for breast cancer. Patients were followed for 24 hours after surgery. Postoperative analgesia was provided with intramuscular diclofenac sodium 1.5 mg every eight hours and IV morphine 3 mg on demand or when the pain score was 4 or higher.

Sample Characteristics:

  • N = 40
  • MEAN AGE = 46.6 years
  • FEMALES: 100%
  • KEY DISEASE CHARACTERISTICS: Breast cancer

Setting:

  • SITE: Single site 
  • SETTING TYPE: Inpatient 
  • LOCATION: Taiwan

Phase of Care and Clinical Applications:

  • PHASE OF CARE: Active antitumor treatment

Study Design:

  • Double-blind, placebo-controlled RCT

Measurement Instruments/Methods:

  • Physiologic measures and medication dosages from medical records
  • 11-point numeric pain rating scale

Results:

Propofol requirements for induction (p = .02) and maintenance of anesthesia (p = .009) was significantly lower in the gabapentin group. Patients in the gabapentin group had significantly lower pain scores up to two hours postoperatively (p < .001). More patients in the control group required rescue analgesics (p = .03). There were no significant differences between groups in duration of surgery or intraoperative analgesics.

Conclusions:

Preoperative gabapentin may reduce anesthesia dose requirements and short-term postoperative pain.

Limitations:

  • Small sample (less than 100)
  • Baseline sample/group differences of import
  • The control group had higher American Society of Anesthesiologists scores at baseline, and although not statistically significant, this could have influenced findings. 
  • Patients were only followed for 24 hours.
  • Authors report lower anxiety with gabapentin preoperatively but do not describe the method or timing of this measure.

Nursing Implications:

Preoperative gabapentin may reduce anesthesia dose needs and postoperative pain.

Grover, V.K., Mathew, P.J., Yaddanapudi, S., & Sehgal, S. (2009). A single dose of preoperative gabapentin for pain reduction and requirement of morphine after total mastectomy and axillary dissection: Randomized placebo-controlled double-blind trial. Journal of Postgraduate Medicine, 55(4), 257–260.

doi:10.4103/0022-3859.58928
Print

Study Purpose:

To investigate the effect of a single low dose (600 mg) of preoperative oral gabapentin on morphine consumption after total mastectomy and axillary dissection; to determine if the specified administration of gabapentin is safe 

Intervention Characteristics/Basic Study Process:

Before total mastectomy and axillary dissection, patients received 600 mg gabapentin or placebo. Pain, sedation, nausea, vomiting, and side effects were monitored every 30 minutes for 2 hours and then every 2 hours until 12 hours after surgery.

Sample Characteristics:

  • The sample was composed of 46 patients.
  • The age range of patients was 18–75 years. In the placebo group, mean patient age was 44.9 years. In the gabapentin group, mean patient age was 46.6 years. 
  • All patients were female. All patients were undergoing total mastectomy with axillary dissection ASA I or II.

 

Setting:

  • Single setting
  • Inpatient
  • Postanesthesia care unit

 

Study Design:

Randomized double-blind placebo-controlled trial

Measurement Instruments/Methods:

  • 100-point pain rating scale
  • Observer’s assessment of alertness or sedation
  • Reports of nausea and number of episodes of vomiting

Results:

  • Postoperative morphine consumption was 48% lower in the gabapentin group than in the placebo group (P < 0.001). 
  • Compared to patients who received gabapentin, patients who received placebo had significantly higher postoperative pain scores and shorter times to rescue dose (P < 0.001).
  • Authors noted no difference between groups in regard to sedation, incidence of nausea, and other side effects.

Conclusions:

Pre-emptive administration of a single oral dose of gabapentin, 600 mg, led to a decrease in the use of postoperative analgesic.

Limitations:

  • The study had a small sample size, with fewer than 100 patients.
  • The study involved only one dose of gabapentin at a single time.
  • The study followed patients for only 12 hours after surgery.

Nursing Implications:

The use of preoperative gabapentin was associated with improved pain control and quality of life, without excessive side effects.

Misra, S., Parthasarathi, G., & Vilanilam, G.C. (2013). The effect of gabapentin premedication on postoperative nausea, vomiting, and pain in patients on preoperative dexamethasone undergoing craniotomy for intracranial tumors. Journal of Neurosurgical Anesthesiology, 25, 386–391.

doi: 10.1097/ANA.0b013e31829327eb
Print

Study Purpose:

To determine if prophylactically administered 600 mg oral gabapentin reduces postoperative nausea or emesis and decreases postcraniotomy pain

Intervention Characteristics/Basic Study Process:

Patients to undergo elective craniotomy were randomized to receive either placebo (a vitamin b-complex capsule) or 600 mg oral gabapentin two hours before induction of anesthesia. All received standard antiepileptic prophylaxis with 100 mg phenytoin every eight hours and 4 mg IV dexamethasone every eight hours for 48 hours prior to surgery. Patients were given 1 gm IV paracetamol every six hours for postoperative pain. Rescue analgesia was provided with 1 mcg/kg IV fentanyl for a pain score of 3. Rescue antiemetic was provided with 4 mg IV ondansetron if the patient had any emetic episode or 10 minutes or longer of nausea. All received the same anesthesia. Symptoms were assessed hourly for the first six hours postoperatively and then every two hours for the next 18 hours.

Sample Characteristics:

  • N = 73  
  • MEAN AGE = 44 years
  • MALES: 68.5%, FEMALES: 31.5%
  • KEY DISEASE CHARACTERISTICS: All were undergoing craniotomy
  • OTHER KEY SAMPLE CHARACTERISTICS: Duration of anesthesia averaged slightly more than 400 minutes and was not different between study groups.

Setting:

  • SITE: Single site   
  • SETTING TYPE: Inpatient   
  • LOCATION: India

Phase of Care and Clinical Applications:

  • PHASE OF CARE: Active antitumor treatment

Study Design:

  • Placebo-controlled RCT

Measurement Instruments/Methods:

  • Pain verbal rating scale of 0 (no pain) to 3 (moderate to severe, requiring rescue)

Results:

Incidence of nausea was 35.1% in the placebo group compared to 11.1% in the gabapentin group (p = .02). No significant difference was seen between groups in incidence of emesis, but there was a trend to lower incidence of emesis with gabapentin. No difference was seen between groups in postoperative pain scores, the number of patients who required rescue analgesia, or postoperative fentanyl consumption.

Conclusions:

Prophylactic oral gabapentin prior to surgery reduced postoperative nausea and vomiting in patients undergoing craniotomy. Perioperative gabapentin had no effect on postoperative pain.

Limitations:

  • Small sample (less than 100)
  • Risk of bias (no blinding)
  • Measurement validity/reliability questionable
  • The method of pain measurement is questionable, as a 3-point scale.

Nursing Implications:

Preoperative gabapentin may reduce postoperative symptoms of nausea and vomiting in patients undergoing craniotomy who are receiving dexamethasone perioperatively. The optimum dosage of gabapentin has not been determined.

Ture, H., Sayin, M., Karlikaya, G., Bingol, C.A., Aykac, B., & Ture, U. (2009). The analgesic effect of gabapentin as a prophylactic anticonvulsant drug on postcraniotomy pain: A prospective randomized study. Anesthesia and Analgesia, 109(5),1625–1631.

doi:10.1213/ane.0b013e3181b0f18b
Print

Study Purpose:

To evaluate the effectiveness of gabapentin in treating acute postoperative pain in patients who have undergone craniotomy

Intervention Characteristics/Basic Study Process:

For anticonvulsant prophylaxis, patients were randomized to one of two groups. One group received 1200 mg oral gabapentin daily (400 mg three times/day). The other received 300 mg oral gabapentin daily (100 mg three times/day). Patients took medications for seven days before surgery, as part of the surgical regimen, and postoperatively. All patients received postoperative morphine via patient controlled analgesia (PCA); the dose was titrated up to 0.1 mg/kg IV according to the pain rating on a visual analog scale (VAS). Postoperative follow-up included noting the VAS and Ramsay sedation scores, morphine consumption, and seizure activity or other adverse effects at 0, 15, and 30 minutes and at 1, 2, 4, 6, 12, 24, and 48 hours.

Sample Characteristics:

  • The sample was composed of 75 patients.
  • Mean patient age was 47 years.
  • Of all patients, 52% were female and 48% were male.
  • All patients had meningioma, glioma, or brain metastases and were undergoing elective supratentorial craniotomy for tumor resection. All patients had tumors with a diameter no larger than 30 mm and a rating of greater than or equal to 15 on the Glasgow coma scale.
  • Excluded from the sample were patients taking tricyclic antidepressants, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, or neuroleptic or antiepileptic drugs.

Setting:

  • Single site
  • Inpatient
  • Turkey

Study Design:

Randomized parallel-group trial

Measurement Instruments/Methods:

  • Visual analog scale, to measure pain
  • Ramsay sedation scale
  • Glasgow coma scale

Results:

  • During the first postoperative hour and at all time points, postoperative VAS scores were significantly higher (p < 0.0001) for those on phenytoin than for those on gabapentin.
  • Compared to patients on gabapentin, patients on phenytoin consumed significantly more morphine (p = 0.01), totally and cumulatively.
  • During the first two hours after surgery, patients on gabapentin had significantly higher sedation scores (p < 0.05) than did patients on phenytoin.
  • Two patients were removed from the study prior to surgery because of apparent side effects of gabapentin. Side effects included severe fatigue and severe dizziness.
  • Patients on gabapentin required less perioperative anesthesia than did patients on phenytoin.
  • Individuals on gabapentin had a longer time to tracheal extubation (16.6 minutes, SD = 22 minutes) compared to those on phenytoin (4.5 minutes, SD = 2 minutes) (p < 0.001).

Conclusions:

Use of gabapentin as a prophylactic anticonvulsant was associated with lower postoperative opioid consumption and lower pain severity. Gabapentin was associated with higher sedation in the immediate postoperative period and a longer time to extubation.

Limitations:

  • The study had a small sample size, with fewer than 100 patients.
  • The study had a risk of bias due to no blinding.
  • The specified use of gabapentin was in a very specific patient population. Findings may not be applicable to other groups of patients.

Nursing Implications:

Gabapentin had significant analgesic effects in patients who had undergone craniotomy, but pain relief was associated with increased sedation and longer time to extubation. In patients undergoing neurosurgery, determining causes of increased sedation or delayed extubation can be difficult and critical. Sedation and delayed extubation can contribute to difficulties in clinical care. Future research should investigate the timing and dosage of gabapentin, with the goal of taking advantage of the drug's positive effects while minimizing negative side effects.

Systematic Review/Meta-Analysis

Yan, P.Z., Butler, P.M., Kurowski, D., & Perloff, M.D. (2014). Beyond neuropathic pain: Gabapentin use in cancer pain and perioperative pain. The Clinical Journal of Pain, 30, 613–629.

Print

Purpose:

STUDY PURPOSE: To conduct a clinical evidence review of gabapentin's use in the management of perioperative pain and cancer-related pain
 
TYPE OF STUDY: Systematic review

Search Strategy:

DATABASES USED: PUBMED and Ovid MEDLINE
 
KEYWORDS: Surgery and cancer, both cross-referenced with gabapentin and pain
 
INCLUSION CRITERIA: Clinical trial studies for the treatment of cancer-related and surgical pain with the quality of evidence at level II-2 or higher; nonhuman studies were included for cancer-related pain
 
EXCLUSION CRITERIA: Nonblinded studies, case reports that did not present a unique finding, and studies that focused on neuropathic pain only

Literature Evaluated:

TOTAL REFERENCES RETRIEVED: 142
 
EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Each abstract was read by two reviewers and was excluded or included based on the criteria detailed in the search strategy. The resulting references were then read, reviewed, analyzed, and discussed with special attention to clinical trials with the quality of evidence at a level II-2 or higher (as defined by Berg, A., & Allan, J. (2001). Introducing the third US Preventive Services Task Force. American Journal of Preventive Medicine, 20, 21–35.)

Sample Characteristics:

  • FINAL NUMBER STUDIES INCLUDED = 48 
  • TOTAL PATIENTS INCLUDED IN REVIEW = Unknown
  • SAMPLE RANGE ACROSS STUDIES: 20–498 patients
  • KEY SAMPLE CHARACTERISTICS: Patients with cancer-related pain treated with gabapentin and postsurgical patients with related pain being treated with gabapentin

Phase of Care and Clinical Applications:

APPLICATIONS: Pediatrics, elder care, and palliative care 

Results:

Gabapentin was found to be effective in reducing pain and the use of analgesics when used perioperatively for otolaryngology, orthopedic, abdominal, and pelvic surgeries as well as mastectomies. There was scant efficacy noted following cardiothoracic surgery. Studies of cancer-related pain management regimens that included gabapentin demonstrated a substantial outcome, which included mild to moderate pain relief with increased efficacy noted in patients with neuropathic pain as well as cancer-related pain.

Conclusions:

Gabapentin was proved to be therapeutic as an adjuvant treatment for cancer-related pain. The authors found multiple studies concluding that gabapentin was effective as part of an analgesic regimen for cancer-related pain. They also effectively described the results of double-blinded, randomized, placebo-controlled research supporting the conclusion in favor of the perioperative use of gabapentin as an adjuvant analgesic.

Limitations:

The articles that were reviewed incorporated disproportionately more patients with breast, lung, and colorectal cancers.

Nursing Implications:

Nurses are in a position to gather additional data and contribute to research, providing more evidence to support the use of gabapentin as an adjuvant analgesic as a part of an effective procedure in the case of perioperative pain. Nurses also are in a position to provide efficient research reviews of studies that evaluate the effect of gabapentin.

Menu