Antidepressants classes

The TCAs are the only antidepressant class in which effectiveness is dependent on serum level. Attainment of the minimal therapeutic level is typically required for effectiveness. Exceeding the maximum treatment level usually provides no additional benefit and risks toxicity. Unique in this regard is nortriptyline, which is the only TCA with a therapeutic window. This means that beyond the maximum therapeutic level of 150ng/mL nortriptyline not only risks toxicity but is actually less effective at treating depression. Please refer to Table 3.9 for a summary of dosing guidelines and therapeutic levels. 

Other Antidepressants. Antidepressant refinements for the next 30 years primarily consisted of the development of new TCAs. However, in 1988, a novel antidepressant class, the selective serotonin reuptake inhibitors (SSRIs), was introduced in the United States. The chief innovation of the SSRIs was that they afforded the comparable effectiveness of the TCAs with fewer side effects and minimal toxicity. The debut of the SSRIs coincided with the reworking of the nosology of the anxiety disorders in DSM-III and DSM-IV. As a result, the SSRIs have been studied extensively in each of the respective anxiety disorders and in many cases have obtained FDA approval for the treatment of one or more of these anxiety syndromes. The SSRIs currently available in the United States include citalopram (Celexa), escitalo-pram (Lexapro), fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil), and sertraline (Zoloft). 

Reboxetine was first introduced to the European market in 1997 for the treatment of depression it is not yet available in the United States. Reboxetine represents a novel antidepressant class, the selective noradrenaline reuptake inhibitors (NRIs). 

For patients who do not respond to a specific antidepressant medication or who do not tolerate its side effects, other antidepressants of the same class or different classes (e.g., venlafaxine for a patient treated with a SSRI) can be tried. The few adult studies published thus far suggest that it is more efficacious to switch antidepressant classes than to stay within the same class, because of the probable heterogeneity in underlying depression mechanisms. Also, it has been suggested that severe depressions appear to respond better to antidepressants with both serotonergic and adrenergic properties (e.g., venlafaxine) (Poirier and Boyer, 1999). 

The commonly used classes of antidepressants are discussed in the following sections, and information about doses and half-lives is summarized in Table 2-1. The antidepressant classes are based on similarity of receptor effects and side effects. All are effective against depression when administered in therapeutic doses. The choice of antidepressant medication is based on the patient s psychiatric symptoms, his or her history of treatment response, family members history of response, medication side-effect profiles, and comorbid disorders (Tables 2-2 and 2-3). In general, SSRIs and the other newer antidepressants are better tolerated and safer than TCAs and MAOIs, although many patients benefit from treatment with these older drugs. In the following sections, clinically relevant information is presented for the antidepressant medication classes individually, and the pharmacological treatment of depression is also discussed. The use of antidepressants to treat anxiety disorders is addressed in Chapter 3. 

Particular care must be exercised when switching from an MAOI to other antidepressant classes. In patients who have completed an MAOI trial without achieving a therapeutic response, treatment with other antidepressants should not be started until 14 days after discontinuation of the original MAOI. Equal care is required when switching from most other antidepressants to an MAOI. An interval equal to five times the half-life of the drug, including active metabolites, is required between stopping treatment with other antide-... 

MAOIs have the most serious pharmacodynamic interactions of any antidepressant class. As discussed earlier, they can cause a hypertensive crisis and the serotonin syndrome. They potentiate the hypertensive effects of most sympathomimetic amines, as well as tyramine, which is the reason for the avoidance of over-the-counter preparations containing such agents, in addition to the tyramine-free diet ( 508, 509). The serotonin syndrome occurs most often when MAOIs are used in combination with SSRIs and venlafaxine but it can also occur when MAOIs are used with tryptophan, 5-hydroxytryptophan, and some narcotic analgesics. In addition, MAOIs can also significantly potentiate the sedative and respiratory depressant effects of narcotic analgesics. 

The use of antidepressants outside the treatment of MDD tends to require specific agents. For example, the TCAs and SNRIs appear to be useful in the treatment of pain conditions, but other antidepressant classes appear to be far less effective. SSRIs and the highly serotonergic TCA, clomipramine, are effective in the treatment of OCD, but noradrenergic antidepressants have not proved to be as helpful for this condition. Bupropion and nortriptyline have usefulness in the treatment of smoking cessation, but SSRIs have not been proven useful. Thus, outside the treatment of depression, the choice of antidepressant is primarily dependent on the known benefit of a particular antidepressant or class for a particular indication. 

SVT supraventricular tachycardia Sx symptom synd syndrome Sz seizure tab/tabs tablet/tablets tach tachycardia TB tuberculosis TBI traumatic brain injury TCA tricyclic antidepressant (class of drugs commonly used to treat depression, e.g., amitriptyline) TCP transcutaneous pacing TD transdermal TFT thyroid function test TIA transient ischemic attack tid three times a day (Latin ter in die ) tine tincture TMP trimethoprim (type of antibiotic)... 

DU 23000 MK 264 Feverin and many other names) is a compound unrelated to the tricyclics or monoamine oxidase inhibitor ANTIDEPRESSANT classes it is a SSRI, a selective serotonin (re-) UPTAKE INHIBITOR. It is extensively used orally to treat depressive illness, and has the advantage over some other antidepressants in that it has relatively less sedative and anticholinergic side-effects, fluvoxamine maleate fluvoxamine. 

Recommendations for sodium bicarbonate vary (from class 1 to class in) depending on the clinical situation. Sodium bicarbonate use is acceptable for patients with known, preexisting hyperkalemia (class 1), preexisting bicarbonate-responsive acidosis (class 11a), overdoses of tricychc antidepressants (class 11a), and to aUcalinize the urine in aspirin and other drug overdoses (class 11a). In addition, sodium bicarbonate may be of benefit in intubated and ventilated patients with along arrest interval (class 11b). Sodium bicarbonate may be harmful in hypercarbic acidosis, and patients with this condition should not receive it (class IH). 

Selective serotonin reuptake inhibitors (SSRIs) are first-line agents when medications are indicated for BN, because of improved tolerability and safety, but they do not have superior efficacy compared with other antidepressant classes. The dose of fluoxetine in BN is higher (60 mg/day) than the dose usually used in depression. 

In summary, the combination of pharmacologic and nonpharmacologic measures appears to produce the best chance for a positive outcome for patients with BN. Antidepressants are the class of choice in patients with BN, while other medications such as mood stabilizers are reserved for patients with comorbid psychiatric conditions. Only in unusual circumstances should patients be treated with antidepressants alone, as the chances for success are not high. SSRIs are the antidepressant class of choice for managing BN patients. Evidence suggests the greatest benefit in the acute phase of treatment, whereas data are more mixed for their role in the prevention of relapse. 

Although the pathophysiology of major depression remains elusive, the clinician can now select from multiple drug therapies with different mechanisms of action. Failure to respond to one antidepressant class or one antidepressant drug within a class does not predict a failed response to another drug class or another drug within the class. 

The antidepressant class of drugs are well-known and widely used today not only for the treatment of mood disorders, such as depression and bipolar disorders, but also for the treatment of neuropathic pain, smoking cessation, and obsessive-compulsive disorders, among others. The application of medicinal chemistry in the development of newer antidepressants, such as selective serotonin uptake inhibitors... 

Table 21.1. Antidepressant Classes with Examples of Generic and Trade Names Drug Classes AbbreviationPrug Examples Trade Names...

Trazodone is a phenylpiperazine-triazolopyridine antidepressant that is structurally unrelated to most of the other antidepressant classes (Fig. 21.22). 

Psychiatric The US Food and Drug Administration s black box advisory warning of the potential for antidepressants to increase the risk of suicidahty in children and adolescents continues to divide opinion. An important contribution to the growing body of evidence on this is a 9-year cohort study of 20906 young new antidepressant users (aged 10-18 years), which reported no differences in the rates of suicidahty between several widely used antidepressant classes selective serotonin re-uptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and serotonin and noradrenahne re-uptake inhibitors (SNRIs). While the rate of attempted or completed suicide was 4.3 cases per 1000 persons—five times that of the general population in this age group— this is likely to have been due to depression and associated psychiatric illnesses [1. ... 

Endocrine A raised prolactin concentration occurs not uncommonly as an adverse effect of antipsychotic drugs but is less often associated with antidepressants. In a comprehensive review of case reports and prospective and retrospective studies, it was documented that all antidepressant classes, except mirtazapine, have been reported to cause hyperprolactinemia [2 ]. However, the findings were mostly derived from case reports and were inconsistent for individual agents within each antidepressant class. 

Are there differences among the antidepressant classes with respect to pain control ... 

In summary, these recent trials illustrate that enhancing depression care has important impacts on pain control, independently of the antidepressant class. Interference with function, related to pain, appears to be a major determinant of depression response. There is a tight intertwining of response to both pain and depression, based on improving both simultaneously. 

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