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G E Sloskey

Publications and source records attributed to G E Sloskey.

5 recordsLinked to original sources
PubMed1987

Encainide hydrochloride and flecainide acetate: two class 1c antiarrhythmic agents.

The chemistry, electrophysiology, pharmacokinetics, clinical use and efficacy, adverse effects, drug interactions, and dosage of encainide hydrochloride and flecainide acetate are reviewed. Encainide and flecainide are class 1c antiarrhythmic agents that slow myocardial conduction and mildly prolong the duration of repolarization. Both agents block anterograde conduction over accessory pathways and prolong the effective refractory period of the accessory pathway. Bioavailability of encainide ranges from 7% to 82%, whereas that of flecainide is 90% to 95%. Encainide is metabolized by the liver to two major active metabolites that are slowly eliminated in the urine. About 23% of flecainide's total body clearance is dependent on renal elimination, and drug excretion is slowed in patients with renal dysfunction, requiring dosage adjustments. Both agents are effective in the suppression and prevention of ventricular arrhythmias, including premature ventricular contractions and sustained and nonsustained ventricular tachycardia. These agents may also be valuable in controlling supraventricular arrhythmias. The most common adverse effects of both agents involve the central nervous system and include dizziness, blurred vision, and headache. The potential for proarrhythmic effects is a concern with these agents. The risk is greater in patients with more severe arrhythmias, poor ventricular function, or high serum concentrations of drug. The usual initial oral dosage of encainide hydrochloride is 25 mg three times a day, with a usual dosage range of 100-200 mg/day. Flecainide acetate should be initiated at 100 mg every 12 hours and may be increased up to 400 mg/day. Encainide and flecainide could become useful therapeutic options in the treatment of a variety of arrhythmias.

Anilides↗
PubMedDate not supplied

Amiodarone: a unique antiarrhythmic agent.

The chemistry, pharmacology, pharmacokinetics, clinical use and efficacy, adverse effects, and dosage of amiodarone, an investigational antiarrhythmic agent, are reviewed. Amiodarone hydrochloride (L3428, Cordarone; Labaz Laboratories) is a benzofuran derivative and contains iodine. Amiodarone is a noncompetitive antagonist of alpha- and beta-adrenergic receptors. It is a type III antiarrhythmic agent and causes prolongation of the action potential of atrial and ventricular tissue. The drug is incompletely and variably absorbed following oral administration; bioavailability ranges from 22 to 86%. Peak serum concentrations occur 2-10 hours after an oral dose. Amiodarone has a large volume of distribution and is widely distributed in body tissues. It is metabolized by the liver; half-life following a single dose is 5-20 hours, but terminal half-lives of 14-58 days have been found following discontinuation of long-term therapy. Amiodarone has been effective in treating supraventricular tachycardias in patients with Wolff-Parkinson-White syndrome whose arrhythmias are refractory to other drugs. Preliminary data suggest a potential use for amiodarone in treating atrial fibrillation/flutter and bradycardia-tachycardia syndrome. The drug has also been tested in patients with ventricular arrhythmias with promising results. Amiodarone has many side effects, some of them serious. The cardiovascular, pulmonary, neurologic, and hepatic systems may be affected; the drug also has deleterious effects on the eyes, thyroid gland, and skin. The usual oral adult dose of amiodarone hydrochloride is 600 mg daily for seven days followed by maintenance doses of 200-400 mg daily during initial therapy. Intravenous initial doses of amiodarone hydrochloride 5 or 10 mg/kg via a central line have been used; these are often followed by infusions of 10 mg/kg/day for three to five days. Amiodarone is an effective antiarrhythmic agent whose use is limited by numerous and sometimes serious side effects. Until more clinical data are available, its use should be restricted to treatment of serious arrhythmias refractory to other agents.

Amiodarone↗