Comparative cardiac effects of maprotiline and doxepin in elderly depressed patients

In a double-blind study, 49 elderly patients with primary major depression, with or without cardiovascular disease, were treated with maprotiline or doxepin. Holter monitors, 12-lead ECGs, and orthostatic blood pressure measurements were used. Maprotiline was associated with decreased PVCs in patients with a "high" baseline rate, while doxepin was associated with increased PVCs in this group. There were no significant differences in orthostatic blood pressure changes between treatment and nontreatment phases or between the two drugs. Small but significant increases in heart rate and prolonged PR interval were noted with both drugs. QRS interval was prolonged by maprotiline but decreased by doxepin. Neither drug produced untoward effects in patients with stable angina or an old myocardial infarction. Maprotiline may have an antiarrhythmic effect which could be beneficial in the treatment of depression with concomitant PVCs. Conversely, doxepin may be more appropriate for depressed patients with heart block or intracardiac conduction delays. Further research is necessary to confirm these suggestions.