Psychotropic drugs and the heart: clinical implications

The cardiovascular effects of antidepressants

This monograph comprises a review of the cardiovascular effects of the various types of antidepressant drugs in clinical use. The frequency, severity and clinical importance of these effects are placed in perspective. Most antidepressants can cause changes in blood pressure. Both the tricyclic type (TCA) and the monoamine oxidase inhibitors (MAOIs) can produce postural hypotension which may be dose-limiting. In addition, the MAOIs may be associated with severe hypertension when amine-containing foods or medicines are ingested. It is unlikely that therapeutic doses of any available antidepressant drug could impair cardiac contractility. Typical TCAs can cause abnormalities of cardiac conduction and arrhythmias, but this affects less than 5% of patients, mostly to a clinically insignificant extent. Newer compounds such as lofepramine, mianserin, trazodone and viloxazine seem safer in this respect. Reports of an association between therapeutic use of TCAs and sudden death are far from convincing. Overdosage with the MAOIs, lithium and carbamazepine is dangerous but not common; overdose with a TCA is a major source of morbidity and mortality. Lofepramine, mianserin and trazodone are relatively safe in overdose. The use of various antidepressants in patients with hypertension, cardiac failure, angina pectoris, myocardial infarction, or cardiac arrhythmias is discussed and guidelines suggested for the selection and use of antidepressant medication.

Electrophysiological and haemodynamic changes with trazodone, amitriptyline and placebo in depressed out-patients

Fourteen out-patients with major depressive disorder completed a double-blind, randomized, parallel group study using trazodone (n = 6), amitriptyline (n = 5) and matching placebo (n = 3). The average daily doses used were 223 mg and 95.3 mg for trazodone and amitriptyline, respectively, over the 28-day treatment period. Cardiovascular function was monitored with high speed ECG and by determining systolic time intervals. No significant effects of either drug on supine or standing blood pressure were demonstrated. Trazodone increased QTc on Day 1 only, and reduced heart rate and increased the PR interval on Day 15; these effects had disappeared by Day 29. Amitriptyline markedly increased heart rate, PR interval and QTc, and reduced T wave amplitude on Days 15 and 29. Trazodone had no consistent effect on systolic time intervals except to increase the LVET index, whereas amitriptyline increased both PEP index and PEP/LVET ratio on Days 15 and 29. It is concluded that amitriptyline had a much more marked effect on cardiac function than did trazodone.