Complete adverse effect profile including incidence rates and management
Important Safety Information
This is not a complete list of all possible side effects. Contact your healthcare provider if you experience any unexpected symptoms. For serious or life-threatening side effects, seek emergency medical attention immediately.
ADVERSE REACTIONS 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% to 9% of patients: Anticholinergic: blurred vision, dry nose/eyes/throat Genitourinary: urinary retention, urinary frequency and urgency Gastrointestinal: nausea, pain/bloating/gas General: dizziness, general fatigue/muscle weakness, headache, malaise, aches/pains The following reactions were reported in 1% to 3% of patients: Genitourinary: impotence Cardiovascular: hypotension with or without congestive heart failure, increased congestive heart failure (see WARNINGS ), cardiac conduction disturbances (see WARNINGS ), edema/weight gain, shortness of breath, syncope, chest pain Gastrointestinal: anorexia, diarrhea, vomiting Dermatologic: generalized rash/dermatoses, itching Central nervous system: nervousness Other: hypokalemia, elevated cholesterol/triglycerides The following reactions were reported in less than 1%: Depression, insomnia, dysuria, numbness/tingling, elevated liver enzymes, AV block, elevated BUN, elevated creatinine, decreased hemoglobin/hematocrit Hypoglycemia has been reported in association with disopyramide phosphate administration (see WARNINGS ).
Infrequent occurrences of reversible cholestatic jaundice, fever, and respiratory difficulty have been reported in association with disopyramide therapy, as have rare instances of thrombocytopenia, reversible agranulocytosis, and gynecomastia.
Some cases of LE (lupus erythematosus) symptoms have been reported;
most cases occurred in patients who had been switched to disopyramide from procainamide following the development of LE symptoms.
Rarely, acute psychosis has been reported following disopyramide phosphate therapy, with prompt return to normal mental status when therapy was stopped.
WARNINGS 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 (e.g., those without recent myocardial infarction) is uncertain.
Considering the known proarrhythmic properties of disopyramide phosphate and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of disopyramide phosphate as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmias.
Negative Inotropic Properties Heart Failure/Hypotension Disopyramide phosphate may cause or worsen congestive heart failure or produce severe hypotension as a consequence of its negative inotropic properties.
Like all medications, Disopyramide Phosphate can cause side effects. However, not everyone who takes this medication will experience them. Many side effects are dose-dependent and may improve as your body adjusts to the medication. Others may require dose adjustment or medical attention.
Contact your healthcare provider promptly if you experience:
Seek immediate emergency medical care if you experience signs of: