EFFECT OF CONCENTRATION ON VASOACTIVITY OF BUPIVACAINE AND LIGNOCAINE

In a double-blind trial bupivacaine 0.125, 0.25 and 0.5% and lignocaine 0.5, 1 and 2% were given intradermally to 31 volunteers. Vasoconstriction was observed more frequently at low concentrations of each drug and vasodilatation at high concentrations. These observations were highly significant (P < 0.001). Duration of action was unaffected by concentration, except in the case of bupivacaine 0.5%, the effect of which was longer lasting than that of other solutions.