Beyond neuropathic pain: gabapentin use in cancer pain and perioperative pain.

BACKGROUND: Gabapentin (GBP), originally an antiepileptic drug, is more commonly used in the treatment of neuropathic pain. In recent years, GBP has been used as an adjunct or primary therapy in non-neuropathic pain, most commonly for the treatment of perioperative and cancer pain.
OBJECTIVES: The aim of this study was to conduct a clinical evidence literature review of GBP's use in perioperative pain and cancer pain.
METHODS: Using PUBMED and OVID Medline databases, keyword searches for surgery and cancer in reference to GBP and pain were carried out. Nonblinded studies and case reports that did not present a unique finding were excluded. Studies that focused only on neuropathic pain were also excluded.
RESULTS: An initial 142 references focusing on GBP's use in surgical pain and cancer pain were identified. Of these, 48 studies were quality of evidence at a level of II-2 or higher. DISCUSSION: Although efficacy varies, multiple well-designed clinical trials have demonstrated reduced pain and analgesic use with otolaryngology, orthopedic, mastectomy, and abdominal/pelvic surgical perioperative use of GBP, whereas there is limited or no efficacy for cardiothoracic surgery. Cancer pain studies have had greater design variability, often nonblinded, with pain benefit being mild to moderate, and more efficacious with partial neuropathic pain quality. Overall, GBP seems to have significant benefit in neuropathic and non-neuropathic pain associated with the perioperative period and cancer. Considering its favorable side effect profile, GBP represents a beneficial pain adjunctive therapy, beyond neuropathic symptoms.