A comparison of oral clonidine versus oral midazolam as premedication in adults

Introduction: Premedication is an important aspect in anaesthesia. We conducted a double blind randomised controlled study to compare the clinical efficacy of oral premedication using clonidine 200 µg versus midazolam 15mg with respect to anxiolytic, sedative, antisialogogue effect and attenuation of haemodynamic response to intubation in adult patients undergoing general anaesthesia for various surgeries. Material and Methods: One hundred patients belonging to ASA 1-2 physical status in the age group of 18-60 years, both males and females, weighing between 50-70 kg were randomly allocated into two groups of 50 each. Group 1 received oral clonidine 200µg and group 2 received midazolam 15mg, both 90 minutes prior to surgery. All patients were given general anaesthesia with thiopentone sodium, vecuronium, fentanyl, oxygen, nitrous oxide and sevoflurane. Patient's level of sedation was assessed using a five point sedation score. The antisialogogue effect was also studied. Pulse rate, systolic, diastolic, mean arterial blood pressure and rate pressure product were the haemodynamic parameters evaluated. Baseline values were obtained and recorded again 90 minutes after premedication. Thereafter, haemodynamic parameters were recorded after induction of anaesthesia with thiopentone sodium and vecuronium; one, five and ten minutes after intubation. Results and Conclusion: Midazolam premedicated patients were sedated to a significantly greater extent than clonidine pretreated patients. Antisialogogue effect was seen in clonidine group. Haemodynamic parameters in the clonidine group were well maintained throughout the study period. There was significant attenuation of pressor response to laryngoscopy and intubation in the clonidine group as compared to midazolam therefore drug of choice for premedication.