Verapamil as a hypotensive agent during neuroleptanaesthesia

The haemodynamic effects of verapamil were investigated in 11 patients anaesthetized with thiopentone, fentanyl and dehydrobenzperidol. Suxamethonium and pancuronium bromide were used for muscle relaxation. Verapamil 0.07 mg kg-1 given as a single intravenous bolus decreased mean arterial pressure from 108 +/- 18 mm Hg to 84 +/- 20 mm Hg (P less than 0.001) and total peripheral resistance by 29 +/- 10% from 1662 +/- 399 dyne s cm-5 (P less than 0.001) while heart rate and mean pulmonary artery pressure showed only minor changes. The decrease in arterial pressure was caused by reduction in total peripheral resistance while cardiac output was increased.