Anti-arrhythmic activity

Several obvious variants exist. Tolbutamide, the prototypic drug, has some anti arrhythmic activity by an unknown mechanism. his side effect has become the principal action with tosifen, which itself does not in turn significantly lower blood... 

Preliminary studies [241, 249, 250] of the cardiovascular and sympatholytic properties of prenylamine demonstrated that coronary blood flow and oxygenation could be increased under experimental conditions (in dogs) and that the drug interacted in complex fashion with sympathetically innervated organs, but the picture presented was someudiat confused because of the many uncontrolled variables and limitations of the actual techniques used. Anti-arrhythmic activity of potency comparable with that of quinidine, plus local anaesthetic properties, were also demonstrated [251] but the same worker was notable to reproduce these effects in intact live animals with any consistency. Large doses of the drug actually provoked cardiac fibrillation in some cases. 

Anti-arrhythmic activity Ethanol (95%), glycerin, and glycerin/ethanol extracts of the leaf, administered intragastrically to rats at a dose of 25 mg/kg, were active vs aconitine-induced arrhythmia " . Ethanol (95%) and glycerin extracts of the seed oil, administered intragastrically to rats at a dose of 25 mg/kg, were active " . Anti-atherosclerotic activity. Extracts of leaves of three isolates (Greek olive leaves [GO], African wild olive leaves [AO], and Cape Town olive leaves [CT]), administered to Dahl salt-sensitive, insulin-resistant rats at a dose of 60 mg/kg for 6 weeks, were active ". ... 

Cobbe SM. Modification of class III anti-arrhythmic activity in abnormal myocardium. Cardiovasc Res 1988 22 847-854. 

Calcium channel blockers inhibit the passage of calcium through the membrane charmels the result in myocardial cells is to depress contractility, and in pacemaker cells to suppress their automatic activity. Members of the group therefore may have negative cardiac inotropic and chronotropic actions. These actions can be separated nifedipine, at therapeutic concentrations, acts almost exclusively on noncardiac ion charmels and has no clinically useful anti-arrhythmic activity whilst verapamil is a useful antiarrhythmic. 

Several cardenolide derivatives of ajmaline alkaloids have been synthesised and tested for their anti-arrhythmic activity. iV(,-(Strophanthidin-3 -yloxycarbonyl mediyl)ajmalinium chloride (167) was found to be one of die most potent of these (210). 

N-Methylation of pr-MDI and bu-MDI and their cis and trans dihydro derivatives to produce the corresponding quaternary ammonium derivatives resulted in significant loss of spasmolytic activity against norepinephrine- and KCL-induced contractions of the rat aorta (43). Similarly Q-bu-MDI had little activity on the force of contraction of the isolated guinea pig atrium as compared to the tertiary compounds (42). This is to be anticipated due to the limited penetration of quaternary compounds into cells. Nevertheless, as mentioned earlier, Q-bu-MDI has potent anti-arrhythmic activity in-vivo (67), possibly due to metabolic activation or accumulation in cardiac tissue. 

Pharm. Bull. 23, 1173 (1975). Anti arrhythmic activity in dogs K. Nakayama et aL, Japan. J. Pharmacol. 29, 935... 

Autotitrator (Parke and Davis method). Evidence for an intramolecular hydrogen bond betwe die amido and pyridine groups of disopyramide is presented, and effects of the resultant ccHistraint on the rotation of die pyridine ring on anti-arrhythmic activity and sippression of anticholinergic activity are discussed... 

A recent review of B-adrenergic blocking agents has appeared, but the anti arrhythmic activities were not fully discussed. The more recent compounds which were not reviewed have been included in this article. 

While lidocaine and procaine amide are effective antiarrhythmics, lack of oral activity s and toxicity has led to the development of newer analogs. The following have been reported to possess local anesthetic and anti arrhythmic activities in a number of experimentally-induced cardiac arrhythmias S u ... 

MODIFIED POLYSACCHARIDES WITH POTENTIAL ANTI-ARRHYTHMIC ACTIVITY... 

The water extractives of the seed had anti-arrhythmic activities in experimental animals, and its total saponins had protective effects on cultured rat myocardial cells. ° ... 

H 93/26 ( c) and H 87/07 (M) were reported to possess considerable cardioselectivity eind H 87/07 had intrinsic activity similar to alprenolol (l e) and practolol.No improvement in anti-arrhythmic activity over propranolol was seen for S-2395 Uf), K-4423 BPE-60 (lh)16 or YB-2... 

Purkinje fibers and rabbit atria.31 Quaternized lidocaine (methyl lido-caine) exhibited the therapeutic efficacy of lidocaine without the CNS side effects of the latter.32 on the other hand, the dimethyl ammonium quaternary salt of bunalol exhibited only weak anti-arrhythmic activity with pronounced myocardial depression.0 ... 

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