Potentiation of the neuromuscular blocking effects of both atracurium and pancuronium by propofal an in vitro study

ABSTRACT

The possible interaction between propofol and the non-depolarizing muscle relaxants is still debatable. This study was carried out to clarify the effect of propofol on the skeletal muscle and its possible interactions with atracurium and pancuronium. The isolated rat phrenic-nerve diaphragm preparation bathed in krebs solution was used in this study. Propofol alone produced concentration dependent muscle relaxation. Moreover it potentiated the neuromuscular blockade of atracurium and pancuronium. The ED50 was significantly reduced from 39.60 [ +/- 1.3] to 26.20 [ +/- 0.72] and from 1.86 [ +/- 0.06] to 1.01 [ +/- 0.04] ug/ml for atracurium and dpancuronium respectively. Although the dose response curves of either atracurium or pancuronium with propofol as fitted by regression line analysis were shifted to the left, there was no difference in their slopes compared to the slope of their curves when they were given alone. In conclusion, the present study suggests that propofol can potentiate the effect of either atracurium or pancuronium. This should be taken in consideration in therapeutic use of propofol. However this needs further clinical assessment