Ling C A, Crouch M A
Department of Pharmacy, Virginia Commonwealth University, Richmond 23298, USA.
Ann Pharmacother. 1998 Jul-Aug;32(7-8):837-9. doi: 10.1345/aph.17463.
The treatment of choice for chronic, symptomatic bradycardia is the placement of a cardiac pacemaker. Individuals who refuse or cannot tolerate pacemaker insertion usually require pharmacologic therapy. Hydralazine, prazosin, anticholinergics, and sympathomimetic agents have been administered for this indication, but adverse effects and limited data hinder routine, long-term use. Theophylline has emerged as a reasonable alternative strategy. For the medical management of bradycardia in the elderly, the literature supports theophylline dosages between 400 and 600 mg/d (approximately 8 mg/kg/d) administered in divided doses. This dosage range should result in a steady-state serum concentration between 5 and 15 mg/L. While some investigators recommend potentially higher initial doses (up to 12 mg/kg/d), lower dosages are more appropriate in the elderly due to decreased theophylline clearance. Initial dosage titration may be indicated and prolonged therapy is expected on the basis of the common etiologies of bradycardia in this patient group. Patient specifics such as altered theophylline metabolism (e.g., smoking), drug interactions (e.g., ciprofloxacin), and concomitant disease states (e.g., hepatic disease, heart failure) should always be considered in theophylline dosage recommendations. Clinicians should adjust the theophylline dose on the basis of patient response, including heart rate and clinical symptomatology, as well as measurement of occasional theophylline concentrations, if deemed appropriate. Theophylline should be avoided in the bradycardia-tachycardia manifestations of sick sinus syndrome or when ventricular ectopy is frequent. Additional investigation will further define the role of theophylline in elderly patients with chronic, symptomatic bradycardia.