Classes
DEA Class; Rx
Common Brand Names; Norpace, Norpace CR
- Antidysrhythmics, Ia
Description
Oral class IA antiarrhythmic; similar pharmacology to procainamide and quinidine
Used only for life-threatening ventricular arrhythmia
Significant proarrhythmic, anticholinergic, and negative inotropic properties limit its use
Indications
Contraindications
Hypersensitivity
Cardiogenic shock, preexisting second or third degree heart block, congenital QT syndrome, sick sinus syndrome
Adverse Effects
- Xerostomia (32%)
- Urinary hesitancy (23%)
- Constipation (11%)
- Impotence
- Urinary urgency
- Urinary retention
- Dry throat
- Weight gain
- Abdominal distension
- Flatulence
- Anorexia
- Vomiting
- Nausea
- Dermatoses
- Pruritus
- Generalized rash
- Increased triglycerides and cholesterol
- Hypokalemia
- Muscle weakness
- Muscular pain
- Dyspnea
- Blurred vision
- Dry eyes
- Fatigue
- Malaise
- Headache
- Dizziness
- Nervousness
- Syncope
- Hypotension
- Chest pain
- Edema
Warnings
CHF, ECG abnormalities, electrolyte abnormalities (hypo/hyper K), glaucoma, hypoglycemia, myasthenia gravis, sick sinus syndrome, BPH/urinary retention, need normal potassium prior to use, hypotension, cardiac myopathies, heart failure, prostatic enlargement, Wolff-Parkinson-White syndrome, bundle branch block, hepatic/renal impairment
Hypotension may occur
May cause QTc prolongation and subsequent torsade de pointes
Can both precipitate and exacerbate HF due to marked myocardial depressant effects in HF
Pregnancy and Lactation
Pregnancy Category: C
Lactation: crosses into breast milk, discontinue drug or do not nurse
Maximum Dosage
800 mg/day PO; however, up to 1600 mg/day PO has been used in the hospital setting to treat severe refractory ventricular tachycardia.
800 mg/day PO; however, up to 1600 mg/day PO has been used in the hospital setting to treat severe refractory ventricular tachycardia.
15 mg/kg/day PO.
5—12 years: 15 mg/kg/day PO.
1—4 years: 20 mg/kg/day PO.
30 mg/kg/day PO.
How supplied
Disopyramide phosphate
capsule
- 100mg
- 150mg
capsule, controlled-release
- 100mg
- 150mg
