Comparative effects of fluoxetine and amitriptyline on cardiac function.

Abstract

1. The effects of fluoxetine and amitriptyline on the electrocardiogram (ECG) and systolic time intervals (STIs) were measured during a double‐ blind parallel‐group study in depressed patients. 2. ECGs and STIs were measured after a 1 week placebo run‐in, following 1 week's treatment with fluoxetine 40 mg daily or amitriptyline 100 mg daily, and then after 3 weeks' treatment with fluoxetine 60‐80 mg daily or amitriptyline 150‐200 mg daily. 3. Fluoxetine had no effect on the ECG or STIs at any dose. Amitriptyline 150‐200 mg daily shortened the sinus cycle length by a mean of 12%, prolonged the PR interval by 8% and the QRS duration by 10%. Amitriptyline did not significantly alter the STIs.