Relation between plasma lignocaine levels and induced haemodynamic changes.
Intravenous lignocaine (1 mg./kg. body weight) was found to produce insignificant haemodynamic changes, and in particular no reduction in myocardial contractility. A rate of 2 mg./minute infused intravenously is suggested for therapeutic purposes.In anaesthetized dogs an infusion of 13.5 mg./minute caused moderate haemodynamic depression and a maximum plasma level of 7 mug./ml. Massive injections of 200 and 400 mg. of lignocaine produced a maximum plasma level of 13.8 and 27.8 mug./ml., respectively, and in the latter failure of myocardial contraction in the presence of a normal E.C.G. ensued ("pump failure"). Lignocaine appears to alter the uptake of calcium by myocardial sarcoplasmic reticulum, and this may explain the negative inotropic effect of large doses.
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000188:drug therapy; D002118:Calcium / Q000378:metabolism; D002302:Cardiac Output / Q000187:drug effects; D002306:Cardiac Volume / Q000187:drug effects; D004285:Dogs; D004562:Electrocardiography; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007263:Infusions, Parenteral; D008012:Lidocaine / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology*; D009203:Myocardial Infarction / Q000188:drug therapy; D009206:Myocardium / Q000378:metabolism
D008012:Lidocaine; D002118:Calcium