[A study of the mechanism of the action of Bunaphtine recording the myocardial monophasic action potentials in man. Conclusive report (author's transl)].
In this paper the authors conclude their study of the mechanism of the action of Bunaphtine. Both atrial and ventricular MAP were recorded by a suction electrode in 13 patients before and after Bunaphtine (1.5-2 and 2.5 mg/Kg i.v.). With the lower dosages, the drug acts specifically on repolarization: it greatly increases the duration of MAP, together with a proportional ERP prolongation; the ERP/MAP ratio is not changed. With the higher dosages, there is a greater effect on the depolarization velocity (decrease of the O dv/dt phase of MAP) and on the conduction, this last being less evident. At the atrial level there is a conspicous ERP prolongation, with a remarkable increase of ERP/MAP ratio. There is full agreement between these results and those obtained experimentally on the dog and in vitro. Bunaphtine has therefore unquestionable antiarrhythmic properties and it can have a double action mechanism; with higher dosages its action-quinidine-like-is predominant at the atrial level.
D000200:Action Potentials / Q000187:drug effects*; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D002082:Butylamines / Q000008:administration & dosage / Q000627:therapeutic use; D004341:Drug Evaluation; D004562:Electrocardiography; D006329:Heart Conduction System / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D009281:Naphthalenes / Q000008:administration & dosage / Q000627:therapeutic use*
D000889:Anti-Arrhythmia Agents; D002082:Butylamines; D009281:Naphthalenes
Studio sul meccanismo d'azione della bunaftine mediante registrazione dei potenziali d'azione monofasici del miocardio nell'uomo. Nota conclusiva