Searle 703
Searle 703 - General Information
A class I anti-arrhythmic agent (one that interferes directly with the depolarization of the cardiac membrane and thus serves as a membrane-stabilizing agent) with a depressant action on the heart similar to that of guanidine. It also possesses some anticholinergic and local anesthetic properties. [PubChem]
Pharmacology of Searle 703
Searle 703 is an antiarrhythmic drug indicated for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia that are life-threatening. In man, Searle 703 at therapeutic plasma levels shortens the sinus node recovery time, lengthens the effective refractory period of the atrium, and has a minimal effect on the effective refractory period of the AV node. Little effect has been shown on AV-nodal and His-Purkinje conduction times or QRS duration. However, prolongation of conduction in accessory pathways occurs.
Searle 703 for patients
Searle 703 Interactions
If phenytoin or other hepatic enzyme inducers are taken concurrently with Norpace or Norpace CR, lower plasma levels of disopyramide may occur. Monitoring of disopyramide plasma levels is recommended in such concurrent use to avoid ineffective therapy. Other antiarrhythmic drugs (eg, quinidine, procainamide, lidocaine, propranolol) have occasionally been used concurrently with Norpace. Excessive widening of the QRS complex and/or prolongation of the Q-T interval may occur in these situations. In healthy subjects, no significant drug-drug interaction was observed when Norpace was coadministered with either propranolol or diazepam. Concomitant administration of Norpace and quinidine resulted in slight increases in plasma disopyramide levels and slight decreases in plasma quinidine levels. Norpace does not increase serum digoxin levels.
Patients taking disopyramide phosphate and erythromycin concomitantly may develop increased serum concentrations of disopyramide resulting in excessive widening of the QRS complex and/or prolongation of the Q-T interval. Patients taking disopyramide phosphate and hepatic enzyme inhibitors concomitantly should be closely monitored.
Until data on possible interactions between verapamil and disopyramide phosphate are obtained, disopyramide should not be administered within 48 hours before or 24 hours after verapamil administration.
Searle 703 Contraindications
Norpace and Norpace CR are contraindicated in the presence of cardiogenic shock, preexisting second- or third-degree AV block (if no pacemaker is present), congenital Q-T prolongation, or known hypersensitivity to the drug.
Additional information about Searle 703
Searle 703 Indication: For the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, ventricular pre-excitation and cardiac dysrhythmias.
Mechanism Of Action: Searle 703 is a Type 1 antiarrhythmic drug (ie, similar to procainamide and quinidine). It inhibits the fast sodium channels. In animal studies Searle 703 decreases the rate of diastolic depolarization (phase 4) in cells with augmented automaticity, decreases the upstroke velocity (phase 0) and increases the action potential duration of normal cardiac cells, decreases the disparity in refractoriness between infarcted and adjacent normally perfused myocardium, and has no effect on alpha- or beta-adrenergic receptors.
Drug Interactions: Acebutolol The beta-blocker increases toxicity of disopyramide
Atenolol The beta-blocker increases toxicity of disopyramide
Azithromycin The macrolide increases the effect of disopyramide
Betaxolol The beta-blocker increases toxicity of disopyramide
Bevantolol The beta-blocker increases toxicity of disopyramide
Bisoprolol The beta-blocker increases toxicity of disopyramide
Carteolol The beta-blocker increases toxicity of disopyramide
Carvedilol The beta-blocker increases toxicity of disopyramide
Cisapride Increased risk of cardiotoxicity and arrhythmias
Clarithromycin Increased risk of cardiotoxicity and arrhythmias
Donepezil Possible antagonism of action
Erythromycin Increased risk of cardiotoxicity and arrhythmias
Esmolol The beta-blocker increases toxicity of disopyramide
Ethotoin The hydantoin decreases the effect of disopyramide
Fosphenytoin The hydantoin decreases the effect of disopyramide
Galantamine Possible antagonism of action
Gatifloxacin Increased risk of cardiotoxicity and arrhythmias
Grepafloxacin Increased risk of cardiotoxicity and arrhythmias
Labetalol The beta-blocker increases toxicity of disopyramide
Levofloxacin Increased risk of cardiotoxicity and arrhythmias
Mephenytoin The hydantoin decreases the effect of disopyramide
Mesoridazine Increased risk of cardiotoxicity and arrhythmias
Metoprolol The beta-blocker increases toxicity of disopyramide
Moxifloxacin Increased risk of cardiotoxicity and arrhythmias
Nadolol The beta-blocker increases toxicity of disopyramide
Penbutolol The beta-blocker increases toxicity of disopyramide
Phenobarbital Phenobarbital decreases levels of disopyramide
Phenytoin The hydantoin decreases the effect of disopyramide
Pindolol The beta-blocker increases toxicity of disopyramide
Practolol The beta-blocker increases toxicity of disopyramide
Propranolol The beta-blocker increases toxicity of disopyramide
Quinupristin This combination presents an increased risk of toxicity
Ranolazine Possible additive effect on QT prolongation
Rifampin Rifampin decreases the effect of disopyramide
Rivastigmine Possible antagonism of action
Sotalol The beta-blocker increases toxicity of disopyramide
Sparfloxacin Increased risk of cardiotoxicity and arrhythmias
Telithromycin Increased risk of cardiotoxicity and arrhythmias
Terfenadine Increased risk of cardiotoxicity and arrhythmias
Thioridazine Increased risk of cardiotoxicity and arrhythmias
Timolol The beta-blocker increases toxicity of disopyramide
Ziprasidone Increased risk of cardiotoxicity and arrhythmias
Oxprenolol The beta-blocker increases toxicity of disopyramide
Food Interactions: Take without regard to meals.
Avoid alcohol.
Generic Name: Disopyramide
Synonyms: Disopiramida [Inn-Spanish]; Disopyramide Free Base; Disopyramide Phosphate; Disopyramidum [Inn-Latin]
Drug Category: Antiarrhythmic Agents
Drug Type: Small Molecule; Approved
Other Brand Names containing Disopyramide: Dicorantil; Isorythm; Lispine; Norpace; Norpace CR; Ritmodan; Rythmodan; Rythmodan P; Rythmodan-La; Searle 703; Xi-Disopyramide;
Absorption: Nearly complete
Toxicity (Overdose): LD50=580 mg/kg in rats
Protein Binding: 50%-65%
Biotransformation: Hepatic
Half Life: 6.7 hours (range 4-10 hours)
Dosage Forms of Searle 703: Tablet, extended release Oral
Capsule Oral
Chemical IUPAC Name: 4-(di(propan-2-yl)amino)-2-phenyl-2-pyridin-2-ylbutanamide
Chemical Formula: C21H29N3O
Disopyramide on Wikipedia: https://en.wikipedia.org/wiki/Disopyramide
Organisms Affected: Humans and other mammals
