Antidepressant drugs antidepressants maintenance therapy

Duration of antidepressant therapy is also an unsettled question. It may be possible in some patients to prevent depressive relapse with a mood-stabilizing drug without maintenance antidepressant therapy following acute treatment with an antidepressant. If so, the risk of a mood switch with continued antidepressant therapy would be reduced. 

Lithium is effective for acute mania, but it may require 6 to 8 weeks to show antidepressant efficacy. It may be more effective for elated mania and less effective for mania with psychotic features, mixed episodes, rapid cycling, and when alcohol and drug abuse is present. Maintenance therapy is more effective in patients with fewer episodes, good functioning between episodes, and when there is a family history of good response to lithium. It produces a prophylactic response in up to two-thirds of patients and reduces suicide risk by eight- to 10-fold. 

TABLE 18 4. Syndromes characterized by therapeutic decrement Progressive treatment resistance to successive antidepressant drug trials Progressive drug intolerance to successive antidepressant drug trials Antidepressant tachyphylaxis ( poop out ) or partial relapse during maintenance therapy... 

The role of benzodiazepines in the treatment of SAD is controversial. Some clinicians prescribe benzodiazepines in combination with an antidepressant in the initial acute management of SAD, then taper the benzodiazepine after 3 to 4 weeks. Others believe that these drugs can be used without risk during continuation and maintenance therapy. 

C. Clinical Use Lithium carbonate is used in the treatment of bipolar affective disorder (manic-depressive disease). Maintenance therapy with lithium decreases manic behavior and reduces both the frequency and the magnitude of mood swings. Drug therapy with neuroleptics or benzodiazepines may also be required at the initiation of lithium treatment. Antidepressant drugs may be required adjunctively during maintenance. Alternative drugs of value in bipolar affective disorder include carbamazepine, clonazepam, gabapentin, and valproic acid. 

An adequate trial of antidepressant medication is defined as treatment with therapeutic doses of a drug for a total of 4 weeks. After 4 weeks of antidepressant treatment, patients can be divided into three groups those who have achieved a full response, those who have achieved a partial response, and those who have not responded. In the case of patients who achieve full remission, treatment should continue for a minimum of 4-6 months, or longer if the patient has a history of recurrent depression (see Maintenance Treatment of Major Depression later in this chapter). If a partial response has been achieved by 4 weeks, a full response may be evident within an additional 2 weeks without further intervention. If the symptoms do not respond at all, the dose should be increased, a different antidepressant should be used, or the therapy should be augmented with another medication (see Treatment-Resistant Depression later in this chapter). 

Furthermore, most psychiatric disorders are chronic, although some may go through intervals of apparent remission (e.g., major depressive disorder), whereas others are persistent but relatively asymptomatic (e.g., schizophrenia) with effective treatment. Flence, treatment with psychotropics is best considered in terms of months or years of continuous or intermittent therapy, rather than a few days or weeks. By contrast, the vast majority of the clinical trials involve short-term use. Thus, a typical database for the approval of a new antidepressant is usually based on experience with 2,000 to 8,000 patients (carefully selected as described earlier), with the majority exposed to the medication for less than 2 months. Often less than 25% will have received medication for more than 4 months, and less than 10% for more than 6 months. When a drug is marketed, most patients will be exposed to it for a minimum of 4 to 6 months. Yet, when treatment goes beyond 2 months, the database on the safety and continued efficacy of a medication is modest at best. Thus, although clinicians commonly use psychotropics for both maintenance and prophylactic purposes, an approved drug only has to be shown effective in the acute phase. 

---