Oral clonidine and gabapentin suppress pressor response: A prospective, randomized, double blind study

Abstract

Background:Pressor response is a part of stress response caused by reflex sympathetic discharge due to direct laryngoscopy and tracheal intubation resulting in tachycardia, hypertension and arrhythmias. Both clonidine, and gabapentin administered orally can effectively blunt this detrimental hemodynamic response.Aim:To study the effect of oral clonidine to blunt the pressor response to direct laryngoscopy and to compare it with oral gabapentin. To observe for postoperative sedation and side effects if any.Settings and Design:Sixty patients of American Society of Anaesthesiologist Grade I and II scheduled for surgery under general anesthesia were considered in this prospective randomized double-blind study. They were randomly allocated into two groups of 30 each using computerized randomization.Materials and Methods:Group A was given oral clonidine 5 μg/kg and Group B was given oral gabapentin 800 mg. Both the drugs were given 90 min prior to surgery. Heart rate (HR) and blood pressure were monitored at baseline, 0, 1, 3, 5, 10, 15, and 30th min of laryngoscopy. Sedation was monitored by Ramsay Sedation Scale score and side effects were noted.Results:HR decreased in both groups at 0 and 1 min, increased at 3rd min and gradually decreased by 30th min. Statistically, significant difference was found between two groups at 1, 3, 5, 10, and 15th min (P < 0.05). Though there was no significant difference in systolic blood pressure, diastolic blood pressure and mean arterial pressure between the two groups, there was no rise in these parameters. Gabapentin produced more sedation than clonidine postoperatively, and few side effects were noted.Conclusion:Both oral clonidine and gabapentin are effective in obtunding pressor response to direct laryngoscopy, clonidine being better in terms of controlling HR. Gabapentin produces more postoperative sedation than clonidine.

A Comparison Between the Effects of Single-Dose Oral Gabapentin and Oral Clonidine on Hemodynamic Parameters in Laparoscopic Surgeries: A Randomized Controlled Trial

“…On comparing patients in Group G with those in Group CL, sedation was statistically higher in Group G up to 16 hours compared to the CL group. Our results correlate with those of the study done by Kapse et al [ 10 ] in which patients had better sedation in the gabapentin group, which is due to the antagonism of NMDA receptors.…”

“…In our study, patients in Group CL and Group G had a significant reduction in HR during pneumoperitoneum compared to patients in Group C. This significant reduction in HR is comparable to the findings of Kapse et al [ 5 ], Singhal et al [ 10 ], and Waikar et al [ 11 ], which showed a statistically significant reduction in HR in clonidine and gabapentin groups during endotracheal intubation and carbon dioxide insufflation. Clonidine, as an alpha-2 adrenergic agonist in the nucleus tractus solitarius (NTS), excites a pathway that inhibits excitatory cardiovascular neurons.…”

“…The MAP was significantly lower in Group CL after abdominal insufflation, compared to Group G, probably due to the synergistic, α2 action of clonidine and hypotension due to the induction agent. Our results are comparable to those of Kapse et al [10] who compared oral clonidine (5 mcg/kg) and oral gabapentin 800 mg given 90 minutes prior to surgery, which showed a significant difference in MAP. Also, our results are in concordance with Singhal et al [5] who compared oral clonidine 200 mcg and gabapentin 900 mg administered 90 minutes before induction, which showed blood pressure below baseline in the clonidine group in comparison with the gabapentin group.…”

“…correlate with those of the study done by Kapse et al [10] in which patients had better sedation in the gabapentin group, which is due to the antagonism of NMDA receptors.…”

“…It also acts on the N-methyl-D-aspartate (NMDA) receptor, which inhibits the substance P and glutamate [ 9 ]. Gabapentin has been used as an adjuvant in the management of acute postsurgical pain and to decrease postoperative opioid requirements [ 10 ]. The mechanism by which gabapentin blunts the pressor response to laryngoscopy and pneumoperitoneum is unclear.…”