ISPUB.COM The Internet Journal of Anesthesiology Volume 30 Number 4 1 of 6 Comparative Evaluation Of Gabapentin, Clonidine And Combination Of Both The Drugs To Attenuate The Pressor Response To Direct Laryngoscopy And Intubation. S Sharma, R Angral, A Jamwal, K Bhanotra Citation S Sharma, R Angral, A Jamwal, K Bhanotra. Comparative Evaluation Of Gabapentin, Clonidine And Combination Of Both The Drugs To Attenuate The Pressor Response To Direct Laryngoscopy And Intubation.. The Internet Journal of Anesthesiology. 2012 Volume 30 Number 4. Abstract Background: The aim of our study was to compare the relative effectiveness of gabapentin and clonidine in attenuation of pressor response to direct laryngoscopy and intubation, and to evaluate the synergistic effect of combination of both drugs.Materials and methods: 120 patients of either sex of age between 20-60 years of American Society of Anaesthesiologist (ASA) grade I and II admitted 24 hours before elective surgery requiring general anaesthesia (GA) were included in the study. Patients were randomly allocated into four groups of 30 patients each: patients received oral 800 mg of gabapentin (group A), 300 µg of clonidine (group B), 400 mg of gabapentin and 150µg of clonidine (group C) and placebo (group D); 60 minutes (min.) prior to induction of anaesthesia. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) were measured before induction, intubation and at 0,1,3,5 and 10 minutes after intubation.Results: Analysis revealed that there was significant rise in HR at 0 minute in all the groups (p<0.05) except in group B. It remained to significant levels in group C and D up to 10 minutes (p<0.001 and p<0.01) but in group A it returned to insignificant level at 3 minutes. There was statistically highly significant rise in SBP, DBP and MAP (p<0.001,p<0.001 and p<0.01) in all the groups except in group A. In group A statistically significant (p<0.001) fall in SBP, DBP and MAP continued up to 10 minutes.Conclusion: Given 60 minutes before induction of GA, oral gabapentin and clonidine in the dose of 800mg and 300µg attenuate the pressor response but gabapentin blunts the increase in arterial blood pressure better than clonidine. The combination of these two drugs in the studied dosage was not effective in attenuating the pressor response to laryngoscopy and intubation. INTRODUCTION Laryngoscopy and intubation performed as a part of GA is a noxious stimulus and is capable of producing marked circulatory effects known as presssor response characterized by tachycardia, hypertension and altered rhythm [1],[2] . Various drugs and techniques have been proposed to prevent or attenuate this response such as deepening of anaesthesia [3] ,omitting cholinergic premedication [4] , use of vasodilators such as nitroglycerine [5] ,beta blockers [6] ,calcium channel blockers [7] and opioids [8] but no single technique has achieved universal acceptance. Gabapentin, a structural analogue of γ-animobutyric acid, is used as an anticonvulsant drug. The inhibition of Ca2+ flux in muscle cells with a consequent inhibition of smooth muscle contraction might explain the effectiveness of gabapentin in attenuation of the pressor response to laryngoscopy. Thus it act in a manner similar to Ca2+ channel blocker [9] . Clonidine is a α 2 -adrenoceptor agonist with sedative and analgesic effects, also has beneficial effect of blunting hyperdynamic responses due to laryngoscopy and tracheal intubation as it decreases the release of stress hormones [10] . Present study was undertaken to study the effects of clonidine 300µg, gabapentin 800mg and their combination in half doses on attenuation of pressor response to laryngoscopy and intubation. MATERIALS AND METHODS After obtaining informed consent and approval from the hospital ethics committee, the randomized controlled trial was conducted on 120 patients of either sex of age between 20-60 years of ASA Grade I and II admitted at least 24 hours before for elective surgery requiring GA. After taking a detailed history, thorough general physical and systemic