Cardiovascular effects of amitriptyline in the treatment of elderly depressed patients

Thirteen elderly depressed patients (age 60-82 years) were treated for 5 weeks with a fixed dose of amitriptyline 100 mg (sustained release preparation). In all patients the sum of concentrations of amitriptyline and nortriptyline exceeded 130 micrograms/l, which is the recommended plasma level. Cardiovascular side effects were recorded by monitoring heart rate, blood pressure, standard ECG and systolic time intervals. During treatment, a transient increase in the supine heart rate was observed without significant changes in the supine blood pressure. The orthostatic drop in blood pressure was markedly increased during treatment without a compensatory increase in heart rate, and these changes remained significant during the whole investigational period. PQ and QRS were significantly increased during treatment, and significant changes in the systolic time intervals were found indicating impairment of myocardial conduction and contractility. In three patients medication was discontinued due to cardiovascular side effects.