Common Mistakes Using Antidepressants in the Elderly
An excessive initial dose of antidepressant medication can cause intolerable sedation. An initial dose of 50mg per day of nortriptyline might lead the patient to discontinue treatment due to intense side effects. However, beginning with a dose of 10mg per day with 10mg increases every 3 to 7 days thereafter achieves the same final dose of 50mg/day and can result in an effective regimen and a patient adherent to the regimen. The adage, "start low and go slow" is a prudent guideline for the elderly when the goal is to maximize compliance and minimize rapid onset of side effects.
It is imperative to allow adequate time for pharmacotherapeutic trials before considering a particular regimen to be a failure. Many patients commonly describe receiving 4 different medication trials in 4 weeks. None of these drug trials is adequate to judge their potential efficacy. A minimum of 4-6 weeks is required to declare that a medication trial has failed.
TCAs such as nortriptyline show a linear dose/serum-level relationship. Nortriptyline has a therapeutic window of 50-150ng/mL, and a serum level of 80-120ng/mL is recommended. Declaring that a trial of nortriptyline has failed without a documented blood level is pure guesswork. In addition, as mentioned earlier, slow metabolizers may become toxic at low doses of nortriptyline, further justifying the use of serum drug levels.
Several SSRIs are effective at single daily doses that do not require much, if any, titration. This fact has improved the delivery of an adequate dose. Many patients who "failed" a drug trial and were referred to psychiatrists experienced in treating geriatric patients were often not given an adequate dosage. Dosage recommendations for some common antidepressants are summarized in Table IV.
To guard against the high recurrence rate of depression in the elderly, the clinician should avoid withdrawing antidepressant medication too soon. Antidepressant medication should be maintained at therapeutic doses for 6-9 months for the first episode of major depression. For a second lifetime episode, continue the medications for at least 1 year. After 3 or more lifetime episodes, consider lifetime maintenance pharmacotherapy. Frank and colleagues reported that in midlife patients, maintenance pharmacotherapy is clearly protective against future episodes in recurrent depression. Preliminary results for a similar study in elderly patients (Maintenance Therapies for Late-Life Recurrent Major Depression) are shown in Figure 3.
Medscape Psychiatry & Mental Health eJournal. 1997;2(2) © 1997 Medscape
Cite this: Recognizing and Treating Depression in the Elderly - Medscape - Mar 06, 1997.