Action of Membrane Stabilizing Agents

The mechanism of action of certain membrane-stabilizing agents are described here under  

Interestingly, the aforesaid metabolites a) and (b) essentially retain only about 33% of the pharmacological activity in comparison to that of quinidine. Furthermore, it has been observed that the quinidine, which being a P-gp substrate, invariably checks the renal tubular seeretion of digoxin via the P-gp efflux pump route, thereby giving rise to an enhanced plasma concentration for digoxin. 

Though its antiarrythmic features are quite identical to those of quinidine and procainamide, yet there exist certain exceptions with regard to its specific antimuscarinic activities which are found to be mueh more marked and pronounced and strategically manifested at the two prominent extracardiac and intracardiac sites. 

Salient Features. The various salient features of the drug are  

Enhances the functional refractoiy period and minimises the relative refraetory period in atrial as well as ventricular cells. 

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