Class I antiarrhythmic drugs produced a spinal anesthetic effect in rats

► Class I antiarrhythmic drugs produced a dose-related spinal anesthetic effect. ► The ranking of potency was bupivacaine > flecainide > quinidine > mexiletine. ► Moreover, flecainide, quinidine and bupivacaine produced similar durations of action. ► These drugs may be potential candidates for developing new local anesthetics.