Monograph Details
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Cardiovascular System
> CHF and arrhythmias
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RYTHMOL SR |
| Manufacturer |
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GlaxoSmithKline Pharmaceuticals |
| Legal Classification |
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Rx
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| Pharmacological Class |
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Class IC antiarrhythmic. |
| Generic Name |
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Propafenone HCl 225mg, 325mg, 425mg; ext-rel caps. |
| Also |
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• RYTHMOL
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| Indications |
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To prolong recurrence of symptomatic atrial fibrillation in patients without structural heart disease. |
| Children |
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Not recommended. |
| Adults |
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Individualize. Not interchangeable on a mg-to-mg basis with immediate-release form (see literature). Swallow whole. Initially 225mg every 12 hrs. May increase at 5-day intervals to 325mg every 12 hrs; max 425mg every 12 hrs. When switching from 150mg three times daily of the immediate-release form, start Rhythmol SR at 325mg twice daily. QRS widening, 2nd or 3rd degree heart block, or hepatic impairment: reduce dose. |
| Contraindications |
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Uncontrolled CHF. Cardiogenic shock. SA, AV and intraventricular disorders of impulse generation +/or conduction (eg, sick sinus syndrome, AV block), unless paced. Bradycardia. Marked hypotension. Bronchospastic disorders. Electrolyte imbalance. |
| Precautions |
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Monitor ECG, pacemakers before and during therapy. Structural heart disease. Discontinue if CHF worsens; reduce dose if 2nd- or 3rd- degree AV block or QRS widening occurs. Monitor for agranulocytosis. Hepatic or renal dysfunction. Elderly. Labor & delivery. Pregnancy (Cat.C). Nursing mothers: not recommended. |
| Interactions |
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Local anesthetics may increase CNS effects. Avoid drugs that may prolong the QT interval (eg, antiarrhythmics, phenothiazines, cisapride, bepridil, tricyclic antidepressants, macrolides). Avoid concomitant quinidine, amiodarone. Potentiates β-blockers, warfarin, digoxin (consider reducing their doses when starting propafenone), desipramine, cyclosporine, theophylline. Antagonized by rifampin. Monitor and adjust dose with CYP2D6, CYP1A2, and CYP3A4 inhibitors. |
| Adverse Reactions |
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New or exacerbated arrhythmias, dysgeusia, GI upset, dizziness, headache, 1st degree AV block, constipation, conduction defects, palpitations, blurred vision, xerostomia, heart failure, bradycardia, elevated ANA titer, exacerbation of myasthenia gravis (immediate-release tabs), edema. |
| How Supplied |
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Tabs, caps—100 |
| Additional Resources |
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• Related Prescribing Note |
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