The effect of aging on the positive chronotropic response to amitriptyline

Amitriptyline (AT) increases sinus heart rate (SHR) due to inhibition of the reuptake of norepinephrine in combination with an antimuscarinic blockade of cardiac vagal inhibition. After 150 mg/day AT for 28 days, the change in SHR was negatively correlated with age in 42 depressed patients who were 18-85 years of age. This finding is consistent with observations that the tachycardic response to antimuscarinics and catecholamines decreases with aging.