Disopyramide Phosphate Medication Summary
No separate FDA Medication Guide was found for this label. This summary is based on FDA/DailyMed prescribing information.
What is this medication?
Disopyramide Phosphate is described in FDA/DailyMed prescribing information. No separate FDA Medication Guide was found for this label. This summary is based on FDA/DailyMed prescribing information.
What is this medication used for?
Disopyramide phosphate is indicated for the treatment of documented ventricular arrhythmias such as sustained ventricular tachycardia, that, in the judgment of the physician, are life-threatening. Because of the proarrhythmic effects of disopyramide phosphate, its use with lesser arrhythmias is generally not recommended. Treatment of patients with asymptomatic ventricular premature contractions should be avoided. Initiation of disopyramide phosphate treatment, as with other antiarrhythmic agents used to treat life-threatening arrhythmias, should be carried out in the hospital. Antiarrhythmic drugs have not been shown to enhance survival in patients with ventricular arrhythmias.
What should I know before taking it?
Disopyramide phosphate is 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.
What important warnings are listed?
Mortality In the National Heart, Lung and Blood Institute’s Cardiac Arrhythmia Suppression Trial (CAST), a long-term, multi-center, randomized, double-blind study in patients with asymptomatic non-life-threatening ventricular arrhythmias who had had a myocardial infarction more than 6 days but less than 2 years previously, an excessive mortality or non-fatal cardiac arrest rate (7.7%) was seen in patients treated with encainide or flecainide compared with that seen in patients assigned to carefully matched placebo-treated groups (3.0%). The average duration of treatment with encainide or flecainide in this study was 10 months. The applicability of the CAST results to other populations.
How is this medication usually taken?
The dosage of disopyramide phosphate capsules must be individualized for each patient on the basis of response and tolerance. The usual adult dosage of disopyramide phosphate capsules is 400 to 800 mg per day given in divided doses. The recommended dosage for most adults is 600 mg/day given in divided doses (150 mg every 6 hours). For patients whose body weight is less than 110 pounds (50 kg), the recommended dosage is 400 mg/day given in divided doses (100 mg every 6 hours). In the event of increased anticholinergic side effects, plasma levels of disopyramide should be monitored and the dose of the drug adjusted accordingly. A reduction of the dose by one third, from the recommended 600.
What side effects are listed?
The adverse reactions which were reported in disopyramide phosphate clinical trials encompass observations in 1,500 patients, including 90 patients studied for at least 4 years. The most serious adverse reactions are hypotension and congestive heart failure. The most common adverse reactions, which are dose dependent, are associated with the anticholinergic properties of the drug. These may be transitory, but may be persistent or can be severe. Urinary retention is the most serious anticholinergic effect. The following reactions were reported in 10% to 40% of patients: Anticholinergic: dry mouth (32%), urinary hesitancy (14%), constipation (11%) The following reactions were reported in 3%.
What interactions are listed?
If phenytoin or other hepatic enzyme inducers are taken concurrently with disopyramide phosphate, 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 (e.g., quinidine, procainamide, lidocaine, propranolol) have occasionally been used concurrently with disopyramide phosphate. Excessive widening of the QRS complex and/or prolongation of the Q-T interval may occur in these situations (see WARNINGS ). In healthy subjects, no significant drug-drug interaction was observed when disopyramide phosphate was coadministered with either propranolol or diazepam. Concomitant.
Where can I find the official prescribing information?
Review the full prescribing information on DailyMed: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=11a68e26-d2e4-48f6-ba0f-9bdd5778f25a
⚠️ Disclaimer
This summary is for educational purposes only and is not medical advice. Always consult your doctor, pharmacist, or other licensed healthcare professional before starting, stopping, or changing any medicine. Read full medical disclaimer.