Gabapentin is Ineffective as an Analgesic Adjunct in the Immediate Postburn Period

Abstract

Successful treatment of burn pain requires a multimodality approach. Although opioid agents are the mainstay, other nonopioid agents, such as anticonvulsants, are frequently employed for pain control, with unknown benefits. The authors sought to determine the efficacy of gabapentin in acute burn pain management. Patients admitted to the burn center with burns more than 5% total body surface area and expected length of stay more than 48 hours were randomized and prospectively enrolled in this double-blind, placebo-controlled study from February 2010 to September 2011. Drug escalation and titration were done by protocol. Pain was assessed by unit protocol with the Numeric Rating Scale. Neuropathic pain and anxiety were recorded at least biweekly. Psychosocial adjustment was assessed at follow-up. Opioid medications were converted to morphine equivalents. Differences between pain levels and opioid consumption were analyzed between groups with the Student's t-test and χ test, respectively. The study was designed to detect a difference of 22% in opioid use between the two study groups with an enrollment of 50 patients with α of 0.05 and β of 80%. P < .5 was considered significant. Fifty-three patients consented for the study and received the loading dose. Four patients withdrew. Both an intention-to-treat and actual treatment analysis were performed on all 53 patients. The placebo and drug populations were well matched for demographic variables, body surface area burned, and need for surgical intervention. The average length of stay was 11 ± 6.8 days and did not vary between groups. The study drug group received 10.8 ± 0.67 days of study drug, with eight patients receiving a dosage of 300 mg thrice daily (TID), 24 receiving 600 mg TID, 14 receiving 800 mg TID, and seven receiving 1200 mg TID. The incidence of neuropathic pain was 39% in the study drug arm and 38% in the placebo group. Neither pain scores (rest and procedural) nor opioid consumption differed between the groups. Forty-three patients (81.1%) were assessed at their first clinic visit. There was no difference in psychosocial functioning in either treatment group. In this randomized, double-blind, placebo-controlled study, the use of gabapentin in acute burn pain management did not decrease pain scores or lessen opioid requirements. Further research into nonopioid alternatives for burn pain analgesia is needed.

Exploring Opioid-Sparing Multimodal Analgesia Options in Trauma: A Nursing Perspective

“…Gabapentinoids have not shown analgesic efficacy in all studies, including two double-blind trials (Pfizer, 2015a; Wibbenmeyer et al, 2014). Although the U.S. Department of Veterans Affairs and the U.S. Department of Defense (2007) recommend gabapentin and pregabalin as options for the treatment of neuropathic pain associated with amputation, gabapentin did not significantly reduce postamputation pain in a double-blind study (Nikolajsen et al, 2006).…”

Sedation and Pain Management in Burn Patients

“…The use of gabapentin as an adjunct to standard analgesia has shown reduction in the severity neuropathic pain in limited studies of burn patients and burn injury models (Gray 2008, Dirks 2002). However, recent data from a randomized, double-blind, placebo-controlled study showed that the use of gabapentin in acute burn pain management did not decrease pain scores or lessen opioid requirements (Wibbenmeyer 2014). Antidepressants and clonidine have also been proposed as potential analgesic options for chronic burn pain but have not been studied extensively.…”

A pharmacological and transcriptomic approach to exploring novel pain targets

“…However, both drugs were only partially anti-allodynic, consistent with effects seen in the clinic 290,294,302 .…”

“…A small human study indicated the administration of a single 1200 mg dose of gabapentin effectively alleviated mechanical allodynia immediately following burn injuries 302 , but lacked efficacy in acute pain post-burn as an adjunct analgesic in a randomised control trial involving 53 patients 290 . Similarly, amitriptyline is widely used for management of chronic pain, and intraplantar administration of amitriptyline also produced thermal antihyheralgesia in a rat model of local mild burn 294 .…”

“…Accordingly, adjuvant analgesics such as antidepressants, anticonvulsants, and non-steroidal anti-inflammatory drugs are used extensively in burn pain 288 , but often with conflicting results 289,290 .…”