Bulimia nervosa and anorexia nervosa are potentially devastating disorders. Bulimia is characterized by episodic intake of large amounts of food (binges) followed by ritualistic purging through emesis, the use of laxatives, or other methods. Medical complications of the purging, such as hypokalemia, are common and dangerous. Anorexia is a disorder in which reduced food intake results in a loss of weight of 15% or more of ideal body weight, and the person has a morbid fear of gaining weight and a highly distorted body image. Anorexia is often chronic and may be fatal in 10% or more of cases.
Antidepressants appear to be helpful in the treatment of bulimia but not anorexia. Fluoxetine was approved for the treatment of bulimia in 1996, and other antidepressants have shown benefit in reducing the binge-purge cycle. The primary treatment for anorexia at this time is refeeding, family therapy, and cognitive behavioral therapy.
Bupropion may have some benefits in treating obesity. Non-depressed, obese patients treated with bupropion were able to lose somewhat more weight and maintain the loss relative to a similar population treated with placebo. However, the weight loss was not robust, and there appear to be more effective options for weight loss.
G. Other Uses for Antidepressants
Antidepressants are used for many other onand off-label applications. Enuresis in children is an older labeled use for some TCAs, but they are less commonly used now because of their side effects. The SNRI duloxetine is approved in Europe for the treatment of urinary stress incontinence. Many of the serotonergic antidepressants appear to be helpful for treating vasomotor symptoms in perimenopause. Desvenlafaxine is under consideration for FDA approval for the treatment of these vasomotor symptoms, and studies have suggested that SSRIs, venlafaxine, and nefazodone may also provide benefit. Although serotonergic antidepressants are commonly associated with inducing sexual adverse effects, some of these effects might prove useful for some sexual disorders. For example, SSRIs are known to delay orgasm in some patients. For this reason, SSRIs are sometimes used to treat premature ejaculation. In addition, bupropion has been used to treat sexual adverse effects associated with SSRI use, although its efficacy for this use has not been consistently demonstrated in controlled trials.
The choice of an antidepressant depends first on the indication. Not all conditions are equally responsive to all antidepressants. However, in the treatment of MDD, it is difficult to demonstrate that one antidepressant is consistently more effective than another. Thus, the choice of an antidepressant for the treatment of depression rests primarily on practical considerations such as cost, availability, adverse effects, potential drug interactions, the patient’s history of response or lack thereof, and patient preference. Other factors such as the patient’s age, gender, and medical status may also guide antidepressant selection. For example, older patients are particularly sensitive to the anticholinergic effects of the TCAs. On the other hand, the CYP3A4-inhibiting effects of the SSRI fluvoxamine may make this a problematic choice in some older patients because fluvoxamine may interact with many other medications that an older patient may require. There is some suggestion that female patients may respond to and tolerate serotonergic better than noradrenergic or TCA antidepressants, but the data supporting this gender difference have not been consistent. Patients with narrow-angle glaucoma may have an exacerbation with noradrenergic antidepressants, whereas bupropion and other antidepressants are known to lower the seizure threshold in epilepsy patients.