The authors treated 44 outpatients 55 years old or older who were
suffering from major depression with either nortriptyline, phenelzine, or
placebo for 7 weeks. Plasma levels of nortriptyline were kept between 50
and 170 ng/ml, and platelet monoamine oxidase (MAO) inhibition in
phenelzine-treated patients was kept between 70% and 80%. ECGs were
compared before and after treatment. Nortriptyline produced statistically
significant increases in both the heart rate and the PR interval, although
none was outside the normal range. Phenelzine produced a significant
decrease in the QT interval. None of the patients had pathological ECG
changes under the closely monitored treatment conditions of this study.Abstract Teaser