A comparative analysis of cetirizine, gabapentin and their combination in the relief of post-burn pruritus

Abstract

Post-burn pruritis is a very distressing symptom having a reported incidence between 80 and 100%. The mainstay of management of post-burn itch has been with antihistaminics and emollients but the treatment is ineffective in a very large percentage of patients. With the recognition of a distinct itch specific neuronal pathway, which has a complex interaction with pain pathway, a fresh approach to itch management has surfaced with the use of gabapentin. Gabapentin is an antiepileptic drug which has been successfully used to manage neuropathic pain, and is reporting to be successful in management of all forms of itch. With a paucity of randomized trials evaluating the role of gabapentin in post-burn itch management the current study was undertaken to individually evaluate gabapentin, cetirizine and their combination in relieving itch. Twenty patients were randomly recruited in each of the three groups and administered the respective drug(s) in doses determined by initial VAS (visual analog scale) scores. There was no significant difference in all the three groups with respect to mean age, sex distribution, mean percentage of TBSA burn and mean VAS score on day 0. VAS scores were evaluated over next 28 days (days 3, 7, 14, 21 and 28), and no emollients were prescribed for the study period. The initial mean VAS score reduced 95% in gabapentin group compared to 52% for the cetirizine group, which was highly significant (p<0.01). There was a 94% reduction in mean VAS score in the combination group which was comparable to the relief observed with gabapentin alone (p>0.05). Even the onset of action with gabapentin was significantly faster than the cetirizine group as evident from the mean VAS scores on day 3, which decreased 74% in gabapentin group compared to 32% in cetirizine group (p<0.01). Whereas all patients receiving gabapentin (either as monotherapy or in combination with cetirizine) reached an itch free status (VAS score 0-1) by day 28 only 3/20 patients reached this level with cetirizine alone. It is quite evident from this study that gabapentin is significantly better than cetirizine as monotherapy in relieving post-burn itch and it also has a faster action. The hypothetical combination of a centrally acting drug with a peripherally acting agent did not result in any better control of post-burn itch than monotherapy with gabapentin. No side effects were reported with gabapentin administration but all patients receiving cetirizine reported sedation. There is now a need to relook at the antipruritic protocols in burn management.