Preinduction oral clonidine: Effects on ketamine cardiostimulation at induction of anaesthesia.

No Thumbnail Available



Journal Title

Journal ISSN

Volume Title


College of Medical Sciences, University of Jos, Jos


Most of the available intravenous (IV) induction agents produce hypotension except ketamine. However, its use is limited due to cardiovascular stimulation. We therefore investigated the effects of oral clonidine premedication on ketamine-induced cardiostimulation. This was a prospective, double-blind randomized controlled study of 156 patients scheduled for general anaesthesia. The patients were randomized into three Groups A, B and C of 52 patients each and all the patients received 10mg diazepam the night before the surgery and 90 minutes before induction of anaesthesia. In addition, patients in Groups A and B received 0.1 mg and 0.3 mg oral clonidine, respectively, at the time of premedication while no clonidine was administered in Group C. Anaesthesia was induced with IV ketamine 2mg/kg and 100% oxygen 8 L/min via the Bain circuit. The pulse rate (PR), systolic blood pressure, diastolic blood pressure, and mean arterial pressure were measured noninvasively and recorded every 10 min before induction of anaesthesia. RESULTS: The peak values of PR in the 0.1 mg and 0.3 mg clonidine groups were significantly lower than the corresponding value in the control (C) group (86 ± 5 bpm and 83 ± 7 bpm vs. 118 ± 14 bpm, p < 0.05). however, the peak mean blood pressure in Group B was significantly reduced when compared with the corresponding values in the Groups A and C (97 ± 9 mm Hg vs 117 ± 7 mm Hg and 115 ± 14 mm Hg, respectively p < 0.05. Preanaesthetic oral clonidine reduced cardiostimulation following ketamine-induction in spontaneously breathing patients.



Attenuation,, cardiovascular stimulations,, ketamine-induction,, pre-anaesthetic clonidine,, spontaneous breathing.


Suleiman ZA, Kolawole IK, Bolaji B.O. (2016). Preinduction oral clonidine: Effects on ketamine cardiostimulation at induction of anaesthesia. Journal of Medicine in the Tropics, 18(1): 12-17.