Antiarrhythmic Drugs1

Jeffrey L. Segar, MD
Peer Review Status: Internally Peer Reviewed

Dosage Recommendations and Pharmacokinetics of the antiarrhythmic drugs1
Drug Initial Dose Effective Plasma Conc T 1/2 GI Absorption Protein Binding Metabolism Renal Excretion (% unchanged) Adverse Effects
Adenosine 50 mcg/kg IV push increasing by 50 mcg/kg q2 min until sinus rhythm. Max: 250 mcg/kg     10 sec         Flushing, dyspnea
Digoxin See page 135   1-2 ng/ml 15-72 hrs (range of means) 70% 20% Liver, GI tract 60% Heart block, arythmia
Lidocaine 1-5 mg/kgIV 10-50 mcg/kg/min IV 1-5 mcg/ml 15-30 min less than 30% 10-50% Liver less than 10% CNS, decreased myocardial contractility, arrhythmia
Phenytoin 2-5 mg/kg IV over 5-10 min, repeat up to 20 mg/kg 2-8 mg/kg q 8-12 hrs P.O. 5-18 mcg/ml 8-197 hrs (range of means) greater than 80% greater than 70% Liver less than 10% Lethargy
Procainamide 3-10 mg/kg IV over 10 min 20-80 mcg/kg/min IV 3-9 mg/kg q4 hrs P.O. 3-10 mcg/ml 2-4 hrs greater than 75% 15% Liver 50-60% Arrhythmia, p ercarditis, pneumonitis
Propranolol 10-20 mcg/kg IV over 10 min 0.05-2 mg/kg q 6 hrs P.O. 20-100 ng/ml 3-6 hrs greater than 90% (less than 30% bioavailable) 90% Liver 5% Bradycardia, hypotension
Quinidine Not recommended 5-15 mg/kg q 6 hrs P.O. 2-6 mcg/ml 6-7 hrs greater than 90% 70-80% Liver 20-50% Arrhythmia, hypotension

1Portions of this information were derived from adult patients

References: Gelband and Rosen, 1975; Guntheroth, 1978; Somogyi et al, 1981; Schreeweiss, 1990; Roberts, 1984