A Comparative Clinical Study of The Effects Of Oral Melatonin and Gabapentin on Preoperative Anxiety, Sedation, Attenuation of Haemodynamic Response During Laryngoscopy and Intubation, and Postoperative Analgesia in Patients Undergoing Laparoscopic Cholec

Abstract

Background: Preoperative anxiety and the haemodynamic stress response to laryngoscopy and tracheal intubation may contribute to perioperative cardiovascular instability and increased anaesthetic requirements. Melatonin and gabapentin have anxiolytic, sedative and analgesic properties and may attenuate these responses.

Aim: To compare oral melatonin and oral gabapentin as premedication for preoperative anxiety, sedation, haemodynamic responses to laryngoscopy and intubation, postoperative pain, time to first rescue analgesia and adverse events in patients undergoing elective laparoscopic cholecystectomy.

Methods: This prospective, randomized, double-blind comparative study included 60 ASA I–II patients aged 18–60 years. Patients received oral gabapentin 600 mg (Group A, n=30) or melatonin 6 mg (Group B, n=30) 90 minutes before induction. Anxiety was assessed using the Hamilton Anxiety Rating Scale (HAMA), sedation using the Ramsay Sedation Score (RSS), haemodynamic variables at predefined peri-intubation time points, postoperative pain using the Visual Analogue Scale (VAS), and time to first rescue analgesia and adverse events.

Results: Baseline characteristics were comparable. Anxiety and sedation scores did not differ significantly between groups. Heart rate, systolic blood pressure and mean arterial pressure were consistently higher after premedication and intubation in the gabapentin group, with significant intergroup differences at most measured time points. Gabapentin significantly prolonged time to first rescue analgesia (452.60 ± 137.06 vs 272.20 ± 145.41 min; P<0.001). Postoperative VAS scores were comparable (2.63 ± 1.33 vs 2.70 ± 1.37; P=0.849). Adverse events were infrequent and not significantly different between groups.

Conclusion: Both agents provided clinically acceptable anxiolysis and sedation. Melatonin showed greater attenuation of the haemodynamic response to laryngoscopy and intubation, whereas gabapentin provided longer postoperative analgesia as reflected by delayed rescue-analgesic requirement. Choice may therefore be individualized according to perioperative priorities.