EXPERIMENTAL EFFICACY OF COMBINED USE OF VERAPAMIL AND ADENOSINE-TRIPHOSPHATE

A wide application of ATP to abolish reciprocal paroxysmal tachycardia is limited by frequent and adverse effects of the drug. Experients on 49 rats have revealed that successive intravenous injections of verapamil and ATP have a more pronounced and prolonged action than the drugs alone. It is assumed that decreased pacemaker activity of sinus nodal cells and reduced atrioventricular conduction (''binodal dysfunction'') are as a result of drug calcium channel block in the cellular membranes of myocytes. Potentiation of the pharmacological action of the drugs in question may be used in the clinical setting to lower an ATP dose and to reduce the incidence of adverse effects.