Quinidine like activity of eight local anaesthetics.

and Md., Eight synthetic local anaesthetics from among (he Propiophenones, Benzil and Phenoxy derivatives and derivatives of Benzyl alcohol wen' examined for their arrhvthmia combating activity. Against acetylcholine induced auricular fibrillation U·0045 showed maximum activity and U -0172, U·OI77, U-OS75 and Lignocaine were more active than quinidine. In aconitine induced fibrillation li.OI77, P-267 and 0-0575 established 'end point' in doses ranging from 2.3 to 4.7 mgjkg. In auricular flutter all the drugs under test showed an activity greater than quinidine. In hydrocarbon-adrenaline induced ventricular arrhythmia only U-0045, U-0069 and U·0575 afforded protection. Suppression of ventricular ectopic activity in the "coronary dog" was exhibited by almost . all the compounds, although the suppressor effect was short-lived. The experiments carried out indicate that all the drugs increased the refractory period, though this does not run parallel to their antiarrhythmic activity. M. (I951l).