Managing geriatric arrhythmias, II: Drug selection and use [published erratum appears in Geriatrics 1991 Jun;46(6):100] Age-related impairments in antiarrhythmic drug distribution, metabolism, and excretion may result in accumulation of these potent drugs, increasing the risk of adverse drug reactions and drug interactions in the elderly. These risks are minimized by using modest initial dosage with slow dosage titration. Therapeutic drug monitoring is a method which employs antiarrhythmic concentration data and a determination of drug clearance in order to develop an optimal dosing regimen. The pharmacology, indications for use, and adverse effects of currently available antiarrhythmics are reviewed. Dosing guidelines for the geriatric population are provided. 