Ingestion of more than 10 mg of digoxin in previously healthy adults or 4 mg of digoxin in previously healthy children, or ingestion causing steady-state serum concentrations greater than 10 ng/mL, often results in cardiac arrest. However, the electrophysiologic effects of some agents span more than one class, and some have ancillary properties unrelated to their antiarrhythmic effects. Adverse reactions: Severe hypotension; bradycardia; ventricular standstill in digitalized patients; asystole; respiratory failure. A reduction of the resting heart rate due to the beta-blocking effect of sotalol is observed at daily doses >/=90 mg/m2 in children. The maintenance infusion of up to 0.5 mg/min can be cautiously continued for 2 to 3 weeks regardless of the patient's age, renal function, or Left-ventricular function. Betapace/Betapace AF, sotalol oral solution, and sotalol injection are also contraindicated in sick sinus syndrome unless a functioning pacemaker is present, hypokalemia (serum potassium less than 4 mEq/L), and/or a baseline QT interval more than 450 msec; for Betapace/Betapace AF, this contraindication only applies if used for the treatment of atrial fibrillation or atrial flutter. Oral dosage of sotalol should be adjusted gradually allowing 2-3 days between dosing increments in order to attain steady-state, and to allow monitoring of QT intervals. Follow
The initial infusion rate should not exceed 30 mg/min. >50 kg: 150 mg every 6 hours or 300 mg every 12 hours (controlled release); if no response, may increase to 200 mg every 6 hours; maximum dose required for patients with severe refractory ventricular tachycardia is 400 mg every 6 hours. The two drugs in this class commonly used in veterinary medicine are The predominant electrophysiologic effect of class IV antiarrhythmic drugs is blockade of the slow calcium channels in cardiac cells and vascular smooth muscle. View All News >
Many antiarrhythmics have never been used with any frequency in veterinary medicine (and are not covered here). Genetic Implication.
Asystole: 1 mg IV - repeat in 3-5 minutes if asystole persists; total dose of 0.04 mg/kg. It is supplied as a white, capsule-shaped tablet for oral administration. The net effect is to shift the equilibrium away from binding of digoxin to its receptors in the body, thereby reversing its effects. concentrations greater than 2 mg/ml should be administered via a central venous catheter). In cats, the dosage of the standard oral formulation is 7.5 mg/cat, PO, tid, and of the sustained-release formulation 30–60 mg/cat, PO, once to twice daily. Second-degree atrioventricular (AV) block, or second-degree heart block, is a disorder characterized by disturbance, delay, or interruption of atrial impulse conduction to the ventricles through the atrioventricular node (AVN). The trusted provider of veterinary information since 1955
Dogs and cats without CHF and with normal systolic function can tolerate higher initial and target dosages. Follow
In addition, many of these agents (in particular the class I medications) have fallen out of favor for treatment of arrhythmias in people, and as a consequence their availability and costs are becoming problematic.Class I agents comprise the group of agents generally known as "membrane-stabilizing drugs" such as Class IA drugs used in veterinary medicine include Toxicities include hypotension and AV block (IV administration only), proarrhythmia (longterm administration), alteration in coat color (longterm administration), and GI disturbances with the oral formulations.Class IB drugs used in veterinary medicine include Examples of drugs in this class include encainide, Class II antiarrhythmic drugs are the β-adrenergic receptor blocking agents. CAPITALS indicate life-threatening, underlines indicate most frequent. 2.1 General Safety Measures for Initiation of Oral Sotalol Therapy . Decrease dose by 30-50% in hepatic insufficiency. ( 267 mg of quinidine gluconate = 275 mg of quinidine polygalacturonate = 200 mg of quinidine sulfate. )