Use of gabapentin and pregabalin for pruritus and neuropathic pain associated with major burn injury: A retrospective chart review.

INTRODUCTION: Pruritis after burn is one of the most common chronic complaints in burn survivors. Pruritus is often indistinguishable from neuropathic pain. There is a paucity of studies reporting the use of gabapentin and pregabalin to treat both pruritus and neuropathic pain. The purpose of this current study is to explore and document the effect of gabapentin and pregabalin in children and adolescent burn survivors.
METHODS: A retrospective review of charts and pharmacy records of gabapentin and pregabalin dispensed to control pruritus and/or pain was conducted for burn survivors up to 20 years of age. Data collected included medication doses, age and weight of patients, presence of neuropathic pain and pruritus, reported response to medication, and side effects of these medications. 136 individuals who received gabapentin, pregabalin, or both medications are included in the study. 112 received only gabapentin, none received only pregabalin, and 24 received both. All results are documented in mean±standard deviation (s.d.) dose/kg/day. 104 individuals experienced pruritus exclusively, two experienced neuropathic pain exclusively, and 30 experienced both. Use of medications was considered effective if the individuals reported pruritus or pain relief from the medication. The medication was considered safe if the individuals did not experience adverse side effects warranting discontinuation of the drugs. Medications were continued with dose adjustments if an individual reported minor side effects such as sedation or hyperactivity.
RESULTS: The average effective dose mg/kg/day for gabapentin and pregabalin was calculated for each of the three age groups (≤5years, 6-12 years, and >12years). The average effective dose of gabapentin was 23.9±10.3mg/kg/day for children ≤5years, 27.0±15.3mg/kg/day for children 6-12 years, and 34.1±15.7mg/kg/day for children >12years. The average effective dose of pregabalin was 6.5±3.5mg/kg/day for children 6-12 years and 4.7±1.6mg/kg/day for children >12years. One 5-year-old child received 3.7mg/kg/day of pregabalin. Note that for all patients in this study, pregabalin was added after an inadequate response to gabapentin. For individuals receiving both gabapentin and pregabalin, the maximum gabapentin failure dose for pruritus was 32.8±18.0mg/kg/day and for both pain and pruritus was 28.1±18.3mg/kg/day. For individuals treated with only gabapentin, 91.4% had an adequate response for pruritus, 100% for neuropathic pain, and 43.3% for both pruritus and pain. 100% of individuals treated with both gabapentin and pregabalin had an adequate response for pruritus and 88.2% had an adequate response for both pruritus and pain. Gabapentin was associated with hyperactivity in two individuals, and sedation in one individual. One individual reported nausea, vomiting, and headaches when taking both medications; this resolved when gabapentin was discontinued. One individual reported sedation while taking both medications.
CONCLUSION: Gabapentin and pregabalin are effective in relieving pruritus and neuropathic pain in most burn survivors. In some instances, these medications can be given together. Few individuals reported side effects.