Nicardipine and verapamil attenuate the pressor response to laryngoscopy and intubation

In a prospective, double-blind study, we compared the efficacy of iv nicardipine hydrochloride and verapamil hydrochloride in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation, in 45 patients undergoing elective surgery with general anaesthesia. Patients were allocated randomly to one of three groups of 15 patients. Patients in Group I received saline while those in Groups II and III received nicardipine hydrochloride, 0.03 mg.kg-1 or verapamil hydrochloride, 0.1 mg.kg-1 iv three minutes before laryngoscopy and intubation. Patients in Group I showed the greatest increase in SBP 25.4 +/- 2.2 2.2 mmHg and HR 35.7 +/- 3.8 beats.min-1 at one minute after intubation (P < 0.001), and these changes persisted throughout the study period albeit with decreasing magnitude. After drug administration, patients in Groups II and III demonstrated increases in HR of 26 +/- 2.4 and 15.1 +/- 2.2 beats.min-1 and decreases in SBP of 24.8 +/- 2.0 and 18.8 +/- 2.4 mmHg respectively (P < 0.001). It is concluded that nicardipine and verapamil are effective in attenuating pressor responses to laryngoscopy and intubation but did not control the tachycardia.