An overview of tricyclic antidepressants use in the geriatric population

Despite the introduction of several new classes of antidepressants, tricyclic antidepressants )TCA( have remained as a prominent choice for management of depressive disorders in the geriatrics due to wealth of evidence in relevant literature and the feasibility of their therapeutic drug monitoring in clinical practice. TCAs with tertiary amine structure are associated with much more frequent and severe adverse reactions compared to those with secondary amine structure. Regarding its effectiveness against a wide range of late-life depressive disorders along with favorable safety profile and specified as well as defined therapeutic window, nortriptyline has been considered as a gold standard TCA in the elderly by most researchersand clinicians. Although the overall clinical efficacy of TCA in geriatrics is believed to be comparable to that observed in younger subjects, but their onset of response appear to be somewhat slower in the elderly compare to younger adults )9-12 versus 6 weeks, respectively(. Geriatrics is generally more vulnerable to adverse reactions of TCA due to age-related physiologic alterations in pharmacodynamics and pharmacokinetics. Therefore, the elderly in comparison to young adults usually need lower doses of TCAs to achieve favorable response and minimize adverse reactions. Treatment with TCAs in geriatrics should be initiated with the least tolerable dose and dose increments should be made gradually based on the patient tolerability. To avoid withdrawal syndrome, TCAs should be tapered by 10%-25% every 1-2 weeks. A comprehensive medical assessment such as the presence of cardiac diseases )especially conduction defects(, glaucoma, and prostate hypertrophy is crucial before starting TCAs in geriatrics. During the TCA treatment, the elderlyshould be closely monitored regarding orthostatic blood pressure, electrocardiogram, electrolytes, serum creatinine, liver function tests, and its blood level after any dose change or adding a new medication with potential pharmacokinetics interactions. Due to the plausible aggravation of their co-morbid diseases, administration of TCAs is considered contraindicated in geriatric patients with Alzheimer’s disease, ischemic heart disease, cardiac conduction abnormality, congestive heart failure, and angle-closure glaucoma.