Pharmacological studies on droxicainide, a new antiarrhythmic agent.

The antiarrhythmic, local anesthetic and acute local and systemic toxic effects of DL-N-(2-hydroxyethyl)-pipecolinyl-2,6-dimethylanilide (AL-S-1249, droxicainide) and lidocaine were compared in animals. When given intravenously both substances suppressed ouabain-induced arrhythmias in pentobarbital-anesthetized guinea pigs; they were equipotent in this regard and had the same duration of antiarrhythmic action. Both substances produced generally equivalent sensory anesthesia following intradermal administration in the guinea pig and corneal application in the rabbit and block of motor and sensory function when injected near the sciatic nerve in the rat. In these local anesthetic tests and following intradermal administration to rabbits, droxicainide produced less local tissue irritation than lidocaine. When given intravenously to unanesthetized mice and unanesthetized and pentobarbital-anesthetized rats, the LD50's for droxicainide were consistently higher than those for lidocaine. Since droxicainide has antiarrhythmic and local anesthetic properties that are quantitatively similar to lidocaine but local and systemic toxicity that is relatively weaker, its antiarrhythmic and local anesthetic actions merit further study.