The effect of non-depolarizing relaxants on plasma potassium

Plasma potassium concentrations were measured in four groups of unpremedicated patients in whom anesthesia was induced with thiopentone 5 mg/kg followed by tubocurarine 0.5 mg/kg, gallamine 2 mg/kg, pancuronium 0.1 mg/kg or AH 8165 1.25 mg/kg, prior to elective dental surgery. There was a small but consistent decrease in plasma potassium following the injection of pancuronium and, to a lesser extent, following gallamine. No changes were found during the first 10 min following tubocurrarine. With AH 8165 there was an early reduction in plasma potassium but the values returned to within normal limits by 5 min.