Ventricular tachycardia disopyramide

The indications for use of disopyramide are similar to those for quinidine, except that it is not approved for use in the prophylaxis of atrial flutter or atrial hbrUla-tion after DC conversion. The indications are as follows unifocal premature (ectopic) ventricular contractions, premature (ectopic) ventricular contractions of multifocal origin, paired premature ventricular contractions (couplets), and episodes of ventricular tachycardia. Persistent ventricular tachycardia is usually treated with DC conversion. 

Disopyramide Premature ventricular contractions Atrial arrhythmias, episodic ventricular tachycardia... 

DISOPYRAMIDE CALCIUM CHANNEL BLOCKERS Risk of myocardial depression and asystole when disopyramide is co administered with verapamil, particularly in the presence of heart failure Disopyramide is a myocardial depressant like verapamil and can cause ventricular tachycardia, ventricular fibrillation or torsades de pointes Avoid co administering verapamil with disopyramide if possible. If single-agent therapy is ineffective, monitor PR, BP and ECG closely watch for heart failure... 

A 35-year-old woman taking disopyramide phosphate modified-release capsules 150 mg qds was given azithromycin 500 mg initially and 250mg/day thereafter (36). In 11 days she developed malaise, light-headedness, and urinary retention. After the insertion of a urinary catheter she developed a monomorphic ventricular tachycardia with left bundle branch block. She was successfully cardioverted and the electrocardiogram... 

Hayashi Y, Ikeda U, Hashimoto T, Watanabe T, Mitsuhashi T, Shimada K. Torsades de pointes ventricular tachycardia induced by clarithromycin and disopyramide in the presence of hypokalemia. Pacing Clin Electrophysiol 1999 22(4 Pt 1) 672. ... 

A 65-year-old woman, who had had normal preoperative serum electrolytes and a normal QT interval with sinus rhythm, received hydroxyzine and atropine premedication followed by thiopental and vecuronium for anesthetic induction. Endotracheal intubation was difficult and precipitated atrial fibrillation, which was refractory to disopyramide 100 mg. Anesthesia was then maintained with sevoflurane 2% and nitrous oxide 50%. Ten minutes later ventricular tachycardia ensued, refractory to intravenous lidocaine, disopyramide, and magnesium. DC cardioversion resulted in a change to a supraventricular tachycardia, which then deteriorated to torsade de pointes. External cardiac massage and further DC cardioversion were initially unsuccessful, but the cardiac rhythm reverted to atrial fibrillation 10 minutes after the sevoflurane was switched off. Two weeks later she had her operation under combined epidural and general anesthesia, with no changes in cardiac rhythm. 

Class I (which has a number of subtypes) is mainly used to treat atrial and ventricular tachycardias, and contains a number of sodium-channel BLOCKERS, e.g. disopyramide, flecainide. lignocaine. procainamide and quinidine. 

Disopyramide, proprietary name Norpace, is used for maintenance of sinus rhythm in patients with atrial flutter and atrial fibrillation and for prevention of ventricular tachycardia and fibrillation. The mechanism of action of disopyramide is similar to that of quinidine, and the drug can be used as replacement therapy for quinidine when quinidine side effects are intolerable. 

Moricizine (600 to 900 mg/day given every 8 hours in three equally divided doses) is indicated in the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, that are life threatening. Because of the proarrhythmic effects of moricizine, its use should be reserved for patients in whom the benefits of treatment outweigh the risks. Moricizine is a class 1C antiarrhythmic agent with potent local anesthetic activity and myocardial-membrane-stabilizing effects. It shares some of the characteristics of the class lA (disopyramide, procainamide, or quinidine), of class IB (lidocaine, mexiletene, phenytoin, or tocainide), or class 1C agents (encainide, flecainide, or propafenone) in that it reduces the fast inward current carried by sodium ions. Moricizine shortens phase 2 and 3... 

DISOPYRAMIDE Disopyramide (norpace, others) exerts electrophysiological effects very similar to those of quinidine, but the drugs have different adverse effects. Disopyramide is used to maintain sinus rhythm in patients with atrial flutter or atrial fibrillation and to prevent recurrence of ventricular tachycardia or ventricular fibrillation. 

Disopyramide phosphate is recommended orally as a prophylaxis of either unifocal or multifocal premature ventricular contractions and ventricular tachycardia. It also exhibits both anticholinergic and local anaesthetic properties. 

Disopyramide (e.g., Norpace) II If Premature atrial depolarization. Atrial fibrillation. Ventricular tachycardia Potent anticnolinergic effects. Otherwise similar to quinidine. 

Eight patients with ventricular tachycardia treated with disopyramide 600 mg to 2 g daily had a 54% fall in their serum disopyramide levels (from a mean of 3.99 to 1.82 micrograms/mL) when they were also given phenytoin 200 to 600 mg daily for a week. Two of the patients who responded to disopyramide and underwent Hotter monitoring showed a 53- and 2000-fold increase in ventricular premature beat frequency as a result of this interaction. ... 

An 82-year-old man developed ventricular tachycardia and torsade de pointes after he took garenoxacin for pneumonia. He had hypokalemia (2.3 mmol/1) due to licorice and had also taken disopyramide, bicalutamide, and silodosin. After withdrawal of all drugs and the administration of spironolactone and oral potassium supplements, the hypokalemia and dysrhythmias resolved. 

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