BACKGROUND: Direct laryngoscopy and tracheal intubation frequently induce transient hypertension, tachycardia and arrhythmia. This study was to evaluate the effect of nicardipine on the changes of the blood pressure and heart rate induced by direct laryngoscopy and tracheal intubation. METHODS: Sixty patients were randomly divided into three groups: Group 1 (nicardipine 0.02 mg/kg, n=20), Group 2 (diltiazem 0.2 mg/kg, n=20), Group 3 (normal saline 3 cc, n=20). Two minutes after intravenous injection of 2 mcg/kg of fentanyl, thiopental 5 mg/kg and nicardipine or diltiazem or normal slaine was administered intravenously. Then succinylcholine 1.5 mg/kg was administered. One minute after succinylcholine injection, direct laryngoscopy and tracheal intubation was done and vecuronium 0.1 mg/kg was injected. Anesthesia was maintained with 50% nitrous oxide in oxygen and 2 vol % of enflurane. Blood pressure and heart rate were measured at the period of preintubation, immediately after intubation, 1, 3 and 5 minutes following intubation by noninvasive method. RESULTS: After tracheal intubation, the increase of systolic blood pressure was supressed significantly in nicardipine and diltiazem group compared with control group (nicardipine group 11%, diltiazem group 13%, control group 24%). The increase of heart rate was greatest in nicardipine group (nicardipine group 38% diltiazem group 29%, control group 20%). CONCLUSIONS: Nicardipine was effective in attenuating pressor responses to laryngoscopy and intubation, but in nicardipine group, increase of heart rate was greater than control group.