Disopyramide is used to treat certain types of irregular heartbeats). Disopyramide is in a class of medications called antiarrhythmic medications. It works by making your heart more resistant to abnormal activity. Technically, disopyramide is a Class IA antiarrhythmic that blocks fast inward sodium channels, reduces phase 0 depolarization, and prolongs the action potential and effective refractory period; it also exhibits some potassium channel blocking that contributes to QT prolongation and has pronounced negative inotropic and anticholinergic properties. The drug is available as the phosphate salt for oral and parenteral administration, is largely hepatically metabolized to N-dealkylated and hydroxylated metabolites, and is eliminated partly by renal excretion. Clinically relevant effects include QRS widening and QT interval prolongation, and dose adjustments or monitoring are required in patients with impaired hepatic or renal function.
Parent: Disopyramide
Parent: Disopyramide
Parent: Disopyramide / Disopyramide Phosphate
Typical pharmaceutical quality specifications target a high assay purity for the disopyramide active ingredient, commonly greater than 98.0 to 99.0 percent w/w by validated HPLC assay. Known related compounds and degradants include N-dealkylated metabolites, N-oxide and hydroxylated oxidation products, trace amounts of starting-material residues and synthesis byproducts, low-level dimers or condensates formed under stress, and residual solvents or counterion-related species from salt formation. As a practical control strategy, individual unidentified impurities are often limited to about 0.1 to 0.2 percent area by HPLC, identified related compounds may be controlled to 0.2 to 0.5 percent depending on toxicity data, and total impurities are typically controlled to around 1.0 percent or lower; residual solvents and heavy metals are controlled to pharmacopeial limits and water content is monitored by Karl Fischer. Specific impurity limits are set in product regulatory filings and pharmacopoeial monographs and will vary with the manufacturing route, stability profile, and applicable regulatory guidance.
Disopyramide is a Class IA antiarrhythmic agent that primarily blocks fast sodium channels, prolongs action potential duration and refractory period, and exhibits additional potassium channel blockade and anticholinergic effects.
No. Disopyramide is not a calcium channel blocker; its primary electrophysiologic action is sodium channel blockade with secondary effects on potassium currents and myocardial contractility.
In hypertrophic cardiomyopathy, disopyramide reduces left ventricular outflow tract obstruction mainly by decreasing myocardial contractility through sodium channel blockade and anticholinergic-mediated reductions in contractile tone, thereby lowering the dynamic gradient; this negative inotropic effect can reduce symptoms and obstruction in selected patients.
Common adverse effects include anticholinergic symptoms such as dry mouth, urinary retention and constipation, and cardiovascular risks including hypotension, negative inotropy that can precipitate or worsen heart failure, QRS widening, QT prolongation with potential proarrhythmia, and other dose-related effects; monitoring for arrhythmias, conduction abnormalities and anticholinergic complications is recommended.
