A Randomized Study of the Effects of Gabapentin on Postamputation Pain

Background: Pain after amputation is common but difficult to treat. Therefore, the authors examined whether postoperative treatment with gabapentin could reduce postamputation stump and phantom pain.

Methods: Forty-six patients scheduled to undergo lower limb amputation were randomly assigned to receive oral gabapentin or placebo. Treatment was started on the first postoperative day and continued for 30 days. The daily dose of gabapentin or placebo was gradually increased to 2,400 mg/day. The intensity of stump and phantom pain was recorded every day on a numeric rating scale (0-10) during the 30-day treatment period. Five interviews were performed after 7, 14, and 30 days and after 3 and 6 months.

Results: Results from 41 patients were included in the data analysis. The risk of phantom pain (gabapentin vs. placebo) was 55.0% versus 52.6% (risk difference, 2.4%; 95% confidence interval, -28.9 to 33.7%; P = 0.88; 30 days) and 58.8% versus 50.0% (risk difference, 8.8%; 95% confidence interval, -23.3 to 40.9%; P = 0.59; 6 months). The median intensity of phantom pain (gabapentin vs. placebo) was 1.5 (range, 0-9.0) versus 1.2 (range, 0-6.6) (P = 0.60; 30 days) and 1.0 (range, 0-6.0) versus 0.5 (range, 0-5.0) (P = 0.77; 6 months). The median intensity of stump pain was 0.85 (range, 0-8.2) versus 1.0 (range, 0-5.4) (P = 0.68; 30 days) and 0 (range, 0-8.0) versus 0 (range, 0-5.0) (P = 0.58; 6 months).     

A randomized study of the effects of gabapentin on postamputation pain

BACKGROUND: Pain after amputation is common but difficult to treat. Therefore, the authors examined whether postoperative treatment with gabapentin could reduce postamputation stump and phantom pain. METHODS: Forty-six patients scheduled to undergo lower limb amputation were randomly assigned to receive oral gabapentin or placebo. Treatment was started on the first postoperative day and continued for 30 days. The daily dose of gabapentin or placebo was gradually increased to 2,400 mg/day. The intensity of stump and phantom pain was recorded every day on a numeric rating scale (0-10) during the 30-day treatment period. Five interviews were performed after 7, 14, and 30 days and after 3 and 6 months. RESULTS: Results from 41 patients were included in the data analysis. The risk of phantom pain (gabapentin vs. placebo) was 55.0% versus 52.6% (risk difference, 2.4%; 95% confidence interval, -28.9 to 33.7%; P = 0.88; 30 days) and 58.8% versus 50.0% (risk difference, 8.8%; 95% confidence interval, -23.3 to 40.9%; P = 0.59; 6 months). The median intensity of phantom pain (gabapentin vs. placebo) was 1.5 (range, 0-9.0) versus 1.2 (range, 0-6.6) (P = 0.60; 30 days) and 1.0 (range, 0-6.0) versus 0.5 (range, 0-5.0) (P = 0.77; 6 months). The median intensity of stump pain was 0.85 (range, 0-8.2) versus 1.0 (range, 0-5.4) (P = 0.68; 30 days) and 0 (range, 0-8.0) versus 0 (range, 0-5.0) (P = 0.58; 6 months). CONCLUSION: Gabapentin administered in the first 30 postoperative days after amputation does not reduce the incidence or intensity of postamputation pain.     

Gabapentin for the treatment of pain in guillain-barré syndrome: a double-blinded,placebo-controlled,crossover study

Pain syndromes of Guillain-Barré are neuropathic as well as nociceptive in origin. We aimed to evaluate the therapeutic efficacy of gabapentin in relieving the bimodal nature of pain in Guillain-Barré syndrome in a randomized, double-blinded, placebo-controlled, crossover study in 18 patients admitted to the intensive care unit for ventilatory support. Patients were assigned to receive either gabapentin (15 mg. kg(-1). d(-1) in 3 divided doses) or matching placebo as initial medication for 7 days. After a 2-day washout period, those who previously received gabapentin received placebo, and those previously receiving placebo received gabapentin as in the initial phase. Fentanyl 2 micro g/kg was used as a rescue analgesic on patient demand or when the pain score was >5 on a numeric rating scale of 0-10. The numeric rating score, sedation score, consumption of fentanyl, and adverse effects were noted, and these observed variables were compared. The numeric pain score decreased from 7.22 +/- 0.83 to 2.33 +/- 1.67 on the second day after initiation of gabapentin therapy and remained low during the period of gabapentin therapy (2.06 +/- 0.63) (P < 0.001). There was a significant decrease in the need for fentanyl from Day 1 to Day 7 during the gabapentin therapy period (211.11 +/- 21.39 to 65.53 +/- 16.17 [ micro g]) in comparison to the placebo therapy period (319.44 +/- 25.08 to 316.67 +/- 24.25 [ micro g]) (P < 0.001). IMPLICATIONS: Gabapentin, an antiepileptic drug, has been used effectively for different types of pain management. This study demonstrates that gabapentin has minimal side effects and is an alternative to opioids and nonsteroidal antiinflammatory drugs for management of the bimodal nature of pain of Guillain-Barré Syndrome patients.     

The analgesic effects of preemptive gabapentin in patients undergoing surgery for brachial plexus injury--a preliminary study

There are reports indicating that gabapentin may have place in the treatment of postoperative pain. No study has evaluated the effects of gabapentin on acute, postoperative pain in patients undergoing surgery for brachial plexus injuries. In this preliminary study, we evaluated gabapentin as preemptive analgesic for intraoperative period and during the acute postoperative period at rest and during movement. Twenty consecutive adult patients undergoing surgery for brachial plexus injury were enrolled for the study. Patients randomly received either oral gabapentin 800 mg or placebo capsules 2 hours before surgery. General anesthesia was induced and maintained with propofol, at bispectral index value between 40 and 60. Intraoperative fentanyl and propofol requirements were noted. Postoperatively, all patients were alert and pain was assessed using visual analog scale (VAS) for 24 hours, both during rest and movement. Whenever VAS score was more than 50 or on patients' demand, ketorolac 30 mg was given as rescue analgesic. The demographics, duration of surgery, and propofol consumption in both groups were comparable. Intraoperative and postoperative heart rate and mean blood pressure were also comparable. Significant difference was noted in intraoperative fentanyl consumption (P=0.03), total dose of rescue analgesic (P=0.004), and VAS score at rest and movement, between the 2 groups; less in gabapentin group as compared with placebo group (P=0.01 and 0.04, at rest and movement, respectively). A single oral dose of gabapentin 800 mg, as preemptive analgesic in patients undergoing surgery for brachial plexus injury is found to be an effective adjunct to intraoperative and postoperative pain. Pain is reduced not only at rest but also during movement.     

Phantom limb, residual limb, and back pain after lower extremity amputations

This study describes the sensations and pain reported by persons with unilateral lower extremity amputations. Participants (n = 92) were recruited from two hospitals to complete the Prosthesis Evaluation Questionnaire which included questions about amputation related sensations and pain. Using a visual analog scale, participants reported the frequency, intensity, and bothersomeness of phantom limb, residual limb, and back pain and nonpainful phantom limb sensations. A survey of medication use for each category of sensations also was included. Statistical analyses revealed that nonpainful phantom limb sensations were common and more frequent than phantom limb pain. Residual limb pain and back pain were also common after amputation. Back pain surprisingly was rated as more bothersome than phantom limb pain or residual limb pain. Back pain was significantly more common in persons with above knee amputations. These results support the importance of looking at pain as a multidimensional rather than a unidimensional construct. They also suggest that back pain after lower extremity amputation may be an overlooked but very important pain problem warranting additional clinical attention and study.     

Effects of gabapentin on experimental somatic pain and temporal summation

BACKGROUND AND OBJECTIVES: Gabapentin is used for treatment of neuropathic pain, but its effect on different somatic pain modalities and integrative mechanisms are not completely understood. The aim of this double-blind, placebo-controlled experimental pain study, conducted on 20 healthy volunteers, was to examine the effect of a single dose of 1200 mg gabapentin on multi-modal experimental cutaneous and muscle pain models. METHODS: The following pain models were applied: (1) pain thresholds to single and repeated cutaneous and intramuscular electrical stimulation (temporal summation to 5 stimuli delivered at 2 Hz); (2) stimulus-response function relating pain intensity scores (visual analog scale, VAS) to increasing current intensities for electrical skin and muscle stimuli (single and repeated, determined at baseline); and (3) the pain intensity (VAS) and pain areas after intramuscular injection of hypertonic saline. Pain assessments were performed prior to, and at 4, 6, and 8 hours after medication. RESULTS: When responses were averaged across the post-dose times, gabapentin: (1) significantly increased the temporal summation pain threshold in skin compared with placebo (P = .03); (2) significantly reduced the area under the pain intensity curve to hypertonic saline injections in the muscle (P = .02); and (3) significantly reduced the area of pain evoked by hypertonic saline (P = .03). CONCLUSIONS: Gabapentin reduces temporal summation of skin stimuli at pain threshold intensities; this may have potential as a biomarker for drugs with efficacy on neurogenic pain. The data also suggest that tonic muscle pain is responsive to gabapentin treatment and suggest further clinical studies.     

Early oral analgesia after fast-track cardiac anesthesia

PURPOSE: Oral analgesia after "fast-track" cardiac anesthesia has not been explored. The aim of this study was to compare two oral oxycodone analgesic regimens. METHODS: One hundred-twenty patients scheduled for coronary artery bypass grafting were randomly assigned postoperatively to receive immediate-release oxycodone 5 mg and acetaminophen 325 mg (Percocet-5) (group I) per os four times daily, or controlled-release oxycodone 10 mg (OxyContin) (group II) per os every 12 hr and placebo twice daily. Acetaminophen 500 mg per os was used as first-line rescue medication, and immediate-release oxycodone (syrup form) 5 mg per os as second-line rescue medication. Pain intensity was assessed with a visual analogue scale on the first postoperative day, the morning after extubation, and thereafter four times daily for four days. Use of rescue medication and adverse events were recorded. RESULTS: Baseline demographic and operation-related characteristics were similar in both groups. While pain control was good in both groups, the immediate-release group experienced less pain on all postoperative days (P = 0.003), required significantly less rescue medication, and had fewer adverse effects such as somnolence and nausea. CONCLUSION: Peroral oxycodone is effective for early pain control after fast-track cardiac anesthesia. Immediate-release oxycodone/ acetaminophen appears to provide better analgesia and fewer side effects compared to controlled-release oxycodone.     

Effects of anesthesia on pain after lower-limb amputation

OBJECTIVE: To evaluate the effects of epidural, spinal, and general anesthesia on pain after lower-limb amputation. DESIGN: Cross-sectional survey. SETTING: Postamputation clinic. PATIENTS: 150 patients who were evaluated one to 24 months after their lower-limb amputation. INTERVENTIONS: Patients received epidural, spinal, or general anesthesia for their amputation. MEASUREMENTS: Standardized questions were used to assess stump pain, phantom sensation, or phantom limb pain preoperatively and postoperatively. Pain intensity was assessed on a verbal rating scale of 0 to 10. After the interview, each patient's medical history and anesthetic record were assessed. RESULTS: Patients who had received epidural anesthesia and those who had received spinal anesthesia recalled significantly less pain in the week after their surgery (P < 0.05). After an average of 14 months, there was no difference in stump pain, phantom limb sensation, or phantom limb pain between patients who received epidural anesthesia, those who received spinal anesthesia, and those who received general anesthesia for their amputation. Phantom limb pain continued to be frequent and severe despite patients' use of opioid analgesics, amitriptyline, and gabapentin. CONCLUSIONS: Patients who received epidural anesthesia and those who received spinal anesthesia recalled better analgesia in the first week after their amputation than did patients who received general anesthesia. Anesthetic technique had no effect on stump pain, phantom limb sensation, or phantom limb pain at 14 months after lower-limb amputation.     

Effects of gabapentin in acute inflammatory pain in humans

BACKGROUND AND OBJECTIVES: The aim of the study was to examine the analgesic effects of the anticonvulsant, gabapentin, in a validated model of acute inflammatory pain. METHODS: Twenty-two volunteers were investigated in a double-blind, randomized, placebo-controlled cross-over study. Gabapentin 1,200 mg or placebo was given on 2 separate study days. Three hours after drug administration, a first-degree burn injury was produced on the medial aspect of the nondominant calf (12.5 cm(2), 47 degrees C for 7 minutes). Quantitative sensory testing (QST) included pain ratings to thermal and mechanical stimuli (visual analog scale [VAS]), assessments of thermal and mechanical detection thresholds, and areas of secondary hyperalgesia. Side effects drowsiness and postural instability were assessed by subjective ratings (VAS). RESULTS: The burn injury induced significant primary and secondary hyperalgesia (P <.0001). Gabapentin diminished the decrease in mechanical pain threshold in the burn area (P =.04) and reduced secondary hyperalgesia, but the reduction was not significant (P =.06). Heat pain thresholds, pain during the burn, and mechanical pain in the area of secondary hyperalgesia were not significantly changed by gabapentin (P <.2). Ratings of drowsiness and unsteadiness during walking were significantly higher for gabapentin than for placebo (P <.05). CONCLUSIONS: The study indicates that gabapentin has no analgesic effect in normal skin, but may reduce primary mechanical allodynia in acute inflammation following a thermal injury. These observations suggest a clinical potential of gabapentin in the treatment of postoperative pain.     

Absence of analgesic effect of intravenous melatonin administration during daytime after laparoscopic cholecystectomy: a randomized trial

Study ObjectiveTo investigate whether melatonin administered intraoperatively reduced pain following laparoscopic cholecystectomy.DesignRandomized, placebo-controlled, double-blinded study.SettingTwo surgical departments in Copenhagen.Patients44 women between 18 and 70 years of age, who were surgical candidates for laparoscopic cholecystectomy.InterventionsPatients were anesthetized by a standard protocol and received a standard multimodal postoperative analgesic regimen. Patients undergoing surgery were admitted on the day of surgery and were discharged the day after surgery. Ten mg of intravenous (IV) melatonin or placebo were administered at the time of surgical incision.MeasurementsPain was assessed by a set of questionnaires documenting “pain at rest” using a visual analog scale (VAS). The use of rescue medication was recorded. Sleep quality and general well-being were measured on separate VAS scales. Sleepiness was assessed by the Karolinska Sleepiness Scale.Main ResultsForty-four patients were included and randomized to the study. Three patients did not complete the study. No differences in VAS pain scores, sleep quality, general well-being, or sleepiness were found between the two groups in the postoperative period. The use of postoperative rescue medication did not differ between the groups.ConclusionsThe use of 10 mg of IV melatonin administered during laparoscopic cholecystectomy did not affect postoperative pain or use of analgesic medication.     

Preemptive gabapentin decreases postoperative pain after lumbar discoidectomy

PURPOSE: We investigated whether the preemptive use of gabapentin, a structural analogue of gamma amino butyric acid could reduce postoperative pain and fentanyl consumption in patients after single-level lumbar discoidectomy. METHODS: Fifty-six ASA I and II patients were randomly allocated into two equal groups to receive either gabapentin 300 mg or placebo two hours before surgery. After surgery, the pain was assessed on a visual analogue scale (VAS) at intervals of 0-6, 6-12, 12-18, and 18-24 hr at rest. Total fentanyl consumption in the first 24 hr after surgery was also recorded. Fentanyl 2 mug.kg(-1) intravenously was used to treat postoperative pain on patients' demand. RESULTS: Patients in the gabapentin group had significantly lower VAS scores at all time intervals of 0-6, 6-12, 12-18, and 18-24 hr than those in the placebo group (3.5 +/- 2.3, 3.2 +/- 2.1, 1.8 +/- 1.7, 1.2 +/- 1.3 vs 6.1 +/- 1.7, 4.4 +/- 1.2, 3.3 +/- 1.1, 2.1 +/- 1.2; P < 0.05). The total fentanyl consumed after surgery in the first 24 hr in the gabapentin group (233.5 +/- 141.9, mean + SD) was significantly less than in the placebo group (359.6 +/- 104.1; P < 0.05). CONCLUSION: Preemptive gabapentin 300 mg po significantly decreases the severity of pain postoperatively in patients who undergo single-level lumbar discoidectomy.     

Gabapentin provides effective postoperative analgesia whether administered pre-emptively or post-incision

PURPOSE: We investigated the effects of pre-incision and post-incision administration of gabapentin on postoperative pain and fentanyl consumption associated with open donor nephrectomy. METHODS: Sixty ASA I subjects were randomly allocated into three groups to receive gabapentin 600 mg two hours before surgery and placebo after surgical incision (pre-incision group), placebo two hours before surgery and gabapentin 600 mg after surgical incision (post-incision group), or placebo two hours before surgery and after surgical incision (placebo group). After surgery, pain was assessed using a visual analogue scale (VAS), (1-10 cm) at time points 0, 6, 12, 18, and 24 hr. Subjects received patient-controlled-analgesia (fentanyl 1.0 microg x kg(-1) subject activated dose). Total fentanyl consumption in each group was recorded. RESULTS: Subjects of pre-incision and post-incision groups had lower VAS scores at all time points (3.1 +/- 1.8, 2.9 +/- 1.3, 2.8 +/- 1.3, 2.5 +/- 0.9, 2.5 +/- 1.5 and 3.6 +/- 1.1, 3.0 +/- 1.2, 3.2 +/- 1.1, 2.9 +/- 1.0, 2.6 +/- 2.2) compared to placebo group (6.6 +/- 1.3, 5.0 +/- 1.0, 4.4 +/- 0.7, 4.2 +/- 0.8, 3.9 +/- 1.0). They also used less fentanyl (563.3 microg +/- 252.8 and 624.0 microg +/- 210.5 respectively) compared to placebo (924.7 microg +/- 417.5), (P < 0.05). No difference in total fentanyl consumption and pain scores at any time points were observed between pre- and post-incision groups. CONCLUSION: Pre-incision administration of 600 mg gabapentin has no added benefit over post-incision administration in terms of pain scores and fentanyl consumption in subjects undergoing open donor nephrectomy.     

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

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.     

Evaluation of the optimal preemptive dose of gabapentin for postoperative pain relief after lumbar diskectomy: a randomized, double-blind, placebo-controlled study

We evaluated the optimal preemptive dose of gabapentin for postoperative pain relief after single-level lumbar diskectomy and its effect on fentanyl consumption during the initial 24 hours in a randomized, double-blinded, placebo-controlled study in 100 patients with American Society of Anesthesiologists physical status I and II. Patients were divided into five groups to receive placebo or gabapentin 300, 600, 900, or 1200 mg 2 hours before surgery. 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 mug/kg on each demand with lockout interval of 10 minutes); total fentanyl consumption during initial 24 hours was recorded. Data were entered into the statistical software package SPSS 9.0 for analysis (one-way analysis of variance and Student-Newman-Keuls test). Patients who received gabapentin 300 mg had significantly lower VAS score at all time points. They consumed less fentanyl (patients who received placebo processed 1217.5 +/- 182.0 versus 987.5 +/- 129.6 mug; P < 0.05). Patients who received gabapentin 600, 900, and 1200 mg had lower VAS scores at all time points than patients who received gabapentin 300 mg (P < 0.05). Increasing the dose of gabapentin from 600 to 1200 mg did not decrease the VAS score, nor did the increasing dose of gabapentin significantly decrease fentanyl consumption (702.5, 635, and 626.5 microg). Thus, gabapentin 600 mg is the optimal dose for postoperative pain relief following lumbar diskectomy.     

Postamputation pain and sensory changes in treatment-naive patients: characteristics and responses to treatment with tramadol, amitriptyline, and placebo

BACKGROUND: Pain after amputation is common but difficult to treat, and few controlled treatment studies exist. METHODS: In the current study, 94 treatment-naive posttraumatic limb amputees with phantom pain (intensity: mean visual analog scale score [0-100], 40 [95% confidence interval, 38-41]) were randomly assigned to receive individually titrated doses of tramadol, placebo (double-blind comparison), or amitriptyline (open comparison) for 1 month. Nonresponders were crossed over to the alternative active treatment. RESULTS: After 1 month, phantom pain intensity was 1 (0-2) in the 48 tramadol responders (mean dose, 448 mg [95% confidence interval, 391-505 mg]), 0 (0-0) in the 40 amitriptyline responders (55 [50-59] mg), and 0 (0-0) in the 2 placebo responders, with similar effects on stump pain. Cytochrome P-450 2D6 slow metabolizers derived greater analgesia from tramadol and less from amitriptyline compared with fast metabolizers in the first treatment week (P < 0.01). Electrical pain thresholds increased and pain during suprathreshold stimulation decreased markedly on the stump and, to a lesser extent, on the contralateral limb after 1 month of treatment with amitriptyline or tramadol. Adverse effects were minor in all groups, but more common with tramadol. CONCLUSIONS: In treatment-naive patients, both amitriptyline and tramadol provided excellent and stable phantom limb and stump pain control with no major adverse events. Both drugs demonstrated consistent and large antinociceptive effects on both the stump and the intact limbs.     

An analgesic model for assessment of acute pain response in osteoarthritis of the knee

BACKGROUND: Osteoarthritis (OA) is frequently treated only during periods of flare, in which rapid onset of analgesia is the outcome target. OBJECTIVE: To assess an acute pain model of knee OA in flare. METHODS: In a multicenter, randomized, double-blind, controlled study, 530 patients aged >or=50 years received valdecoxib 10 mg qd (n=212), rofecoxib 2 5 mg qd (n=208), or placebo (n=110). Pain intensity (PI) was measured on a visual analog scale (VAS) at baseline after a 10-min walk. Patients took their first dose of study medication, rested for 20 min, then measured their PI VAS at 0.5, 1, 1.5, 2, 3, 4, 5, and 6h, each time following a 10-min walk. RESULTS: PI VAS differences (PID) were significantly greater vs placebo both with valdecoxib and rofecoxib (P<0.05) beginning as early as 3h (intent-to-treat population). The percentage of patients with analgesia onset from 4h was significantly higher with both valdecoxib (55%) and rofecoxib (56%) relative to placebo (40%). Median time to first onset of analgesic was shorter with both valdecoxib and rofecoxib compared with placebo (P=0.104 vs valdecoxib; P=0.036 vs rofecoxib). CONCLUSIONS: This acute pain model of knee OA flare detected significant pain relief with agents known to relieve pain in OA and placebo within hours after the first treatment dose, allowing assessment of pain relief within hours rather than days or weeks when evaluating analgesic efficacy in OA. This model is undergoing further study to determine optimal walk times, distances, and rates to maximize its sensitivity.     

Efficacy of preoperative oral rofecoxib in pain control for third molar surgery.

OBJECTIVE: The study compared the analgesic efficacy of preoperative 50 mg oral rofecoxib, 400 mg ibuprofen, and placebo in the control of postoperative pain after third molar surgery. STUDY DESIGN: This was a clinical randomized, double-blind, cross-over, placebo- and active-comparator-controlled study. The surgeries were randomized into 3 groups, in which patients were given a single dose of 50 mg rofecoxib, 400 mg ibuprofen, or placebo 30-60 minutes before the surgery. The patients were asked to quantify their pain intensity basing on a visual analog scale postoperatively. A rescue medication, 500 mg acetaminophen, was prescribed to the patients. The quantity and time of consumption of the rescue tablets were recorded by the patients. RESULTS: A total of 49 patients completed the study. Of the 98 lower third molar extractions 33 were with rofecoxib, 33 ibuprofen, and 32 placebo. The pain scores within the first 6 hours postoperatively in the rofecoxib group were significantly lower than the placebo ( P < .05). The ibuprofen group did not have significantly lower pain scores than the placebo group. Regarding the postoperative requirement of rescue medication, the rofecoxib group required significantly less rescue medication than both ibuprofen and placebo groups in the first twelve hours after the surgery. CONCLUSIONS: The preoperative oral intake of 50 mg rofecoxib provides a significantly better analgesic benefit than the placebo for postoperative pain relief in the first 6 hours after third molar surgery. This regimen also reduced the requirement of postoperative analgesic when compared with ibuprofen and placebo in the first 12 postoperative hours.     

Preemptive use of gabapentin significantly decreases postoperative pain and rescue analgesic requirements in laparoscopic cholecystectomy

PURPOSE: To evaluate the comparative preemptive effects of gabapentin and tramadol on postoperative pain and fentanyl requirement in laparoscopic cholecystectomy. METHODS: Four hundred fifty-nine 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. Postoperatively, patients' pain scores were recorded on a visual analogue scale every two hours for the initial 12 hr and thereafter every three hours for the next 12 hr. Patients received fentanyl 2 micro g*kg(-1) intravenously on demand. The total fentanyl consumption for each patient was recorded. RESULTS: Patients in the gabapentin group had significantly lower pain scores at all time intervals (2.65 +/- 3.00, 1.99 +/- 1.48, 1.40 +/- 0.95, 0.65 +/- 0.61) in comparison to tramadol (2.97 +/- 2.35, 2.37 +/- 1.45, 1.89 +/- 1.16, 0.87 +/- 0.50) and placebo (5.53 +/- 2.22, 3.33 +/- 1.37, 2.41 +/- 1.19, 1.19 +/- 0.56). Significantly less fentanyl was consumed in the gabapentin group (221.16 +/- 52.39 micro g) than in the tramadol (269.60 +/- 44.17 micro g) and placebo groups (355.86 +/- 42.04 micro g; P < 0.05). 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. CONCLUSION: Preemptive use of gabapentin significantly decreases postoperative pain and rescue analgesic requirement in laparoscopic cholecystectomy.     

Analgesic Effects of Intravenous Lidocaine and Morphine on Postamputation Pain: A Randomized Double-blind, Active placebo-controlled, Crossover Trial

Background: Phantom and stump pains, common sequelae of limb amputations, are significant impediments to rehabilitation of amputees. The pathophysiology and optimal treatment of postamputation pain states are unclear. While stump pain may result from neuromas in the stump, phantom pain is thought to be related to cortical reorganization. The authors hypothesized that morphine and lidocaine may have differential effectiveness on stump and phantom pains.

Methods: The authors conducted a randomized double-blind, active-placebo-controlled, crossover trial to compare the analgesic effects of intravenous morphine and lidocaine on postamputation stump and phantom pains. An intravenous bolus followed by an intravenous infusion of morphine (0.05 mg/kg bolus + 0.2 mg/kg infusion over 40 min), lidocaine (1 mg/kg bolus + 4 mg/kg infusion) and the active placebo, diphenhydramine (10 mg bolus + 40 mg infusion), were performed on three consecutive days. Phantom and stump pain ratings and sedation scores were recorded at 5-min intervals using a 0-100 visual analog scale. Pain measures were initiated 30 min before drug infusion and continued until 30 min after the end of infusion. Subjects' self-reported pain relief and satisfaction were assessed at the end of each infusion.

Results: Thirty-one of 32 subjects enrolled completed the study. Eleven subjects had both stump and phantom pains, 11 and 9 subjects had stump and phantom pain alone, respectively. Baseline pain scores were similar in the three drug groups. Compared with placebo, morphine reduced both stump and phantom pains significantly (P < 0.01). In contrast, lidocaine decreased stump (P < 0.01), but not phantom pain. The changes in sedation scores for morphine and lidocaine were not significantly different from placebo. Compared with placebo, self-reported stump pain relief was significantly greater for lidocaine (P < 0.05) and morphine (P < 0.01), while phantom pain relief was greater only for morphine (P < 0.01). Satisfaction scores were significantly higher for lidocaine (mean +/- SD: 39.3 +/- 37.8, P < 0.01) and morphine (45.9 +/- 35.5, P < 0.01) when compared with placebo (9.6 +/- 21.0).