A four arm, double blind, randomized and placebo controlled study of pregabalin in the management of post-burn pruritus.

Rajeev B Ahuja, Gaurav K Gupta

Index: Burns 39(1) , 24-9, (2013)

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Abstract

Post-burn itch is a distressing symptom in burns rehabilitation and its treatment often proves frustrating for the patient and the multidisciplinary burns team. Traditionally, the mainstay of antipruritic therapy for decades has been antihistamines and massage with emollients. With a better understanding of the neurophysiology of itch emerged a new dimension in the treatment of post-burn pruritus. Gabapentin, a centrally modulating anti-epileptic agent and α2δ ligand, proved in clinical trials to be immensely better in the treatment of post-burn pruritus. Pregabalin is a newer structural analog of gabapentin. It has a much better anxiolytic effect and pharmacokinetic profile as compared to gabapentin. The current study was initiated to specifically study the role of pregabalin in relieving post-burn itch as this has never been investigated before. This double blind, randomized and placebo controlled study had four arms and was carried out on 80 adult patients (20 each). The four arms were: pregabalin, cetirizine with pheniramine maleate, combination of pregabalin, cetirizine and pheniramine maleate, and placebo (vit. B comp.). Massage with coconut oil was integral to all groups. Drug dosage was determined by initial VAS (visual analog scale) scores. All groups matched in demographic data and initial VAS scores. VAS scores were evaluated over next 28 days (days 3, 7, 14, 21 and 28). In patients with mild itch (VAS scores 2-5) or moderate itch (VAS scores 6-8) near complete remission of itch was seen in combination group and pregabalin group where the response was comparable and close to 95%. This was significantly better response than antihistaminic combination or massage alone. However, massage alone was sufficient in decreasing mean scores in mild itch, in a large percentage of patients. Amongst the patients with severe itch (VAS scores 9-10), 3/6 and 6/7 patients dropped out of trial in the antihistaminic and placebo groups, respectively. Combination therapy and pregabalin alone had exactly similar decrease in itch scores by day 28 (78.9%). This far exceeded the response in the antihistaminic and placebo groups (23.9% and 9.2% respectively). We conclude that moderate to severe pruritus (VAS 6-10) should be treated with a systemic, centrally acting agent like pregabalin or gabapentin to eliminate itch or bring it down to tolerable limits. Patients with mild itch having VAS scores between 4 and 5 may be better served with addition of pregabalin even if massage and antihistaminics can control post-burn itch to a reasonable extent because of quicker, predictable and complete response, along with anxiolysis.Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.