Weight gain tricyclic antidepressant

Common side effects of the SSRIs are somnolence, nausea, ejaculation disorders, decreased libido, dry mouth, insomnia, and fatigue. Tricyclic antidepressants (TCAs) commonly cause sedation, orthostatic hypotension, anticholinergic effects, and weight gain. TCAs are very toxic on overdose. 

Antidepressants. There are numerous reasons to expect that antidepressants may be helpful in the treatment of AN. First, depressed mood and other symptoms of depression such as anhedonia, decreased energy, poor concentration, and psychomotor retardation are common in cases of starvation from any cause. Second, AN patients and their family members have high rates of comorbid MDD and OCD, illnesses best treated with antidepressant medications. Finally, weight gain is a well-documented side effect of many antidepressants including the tricyclic antidepressants (TCAs) and mirtazapine. 

Tricyclic Antidepressants (TCAs). The TCAs have been nsed to treat ADHD for 30 or more years. Most often used are imipramine (Tofranil) and desipramine (Norpramin), mainly becanse they are the TCAs that most specihcally increase norepinephrine activity. Remember, boosting norepinephrine activity in the brain shonld improve attention. Other TCAs, namely, amitriptyline (Elavil, Endep) and nortriptyline (Pamelor), have been used, though they also increase norepinephrine activity. TCAs do offer a modest benefit for both the inattention and the hyperactivity of ADHD. In addition, they are often effective at doses mnch lower than those required to treat depression. However, their effectiveness nsnally falls short of the stimulant medications. In addition, TCAs have considerable side effects including dry mouth, constipation, drowsiness, weight gain, and adverse cardiac effects. 

Equal efficacy as tricyclic antidepressants advantages include minimal anticholinergic effects, lack of orthostatic hypotension, no cardiac conduction problems, absence of weight gain, no sedation... 

Long-term efficacy and tolerability is of considerable clinical importance for any medication proposed for the treatment of panic disorder. Tricyclic antidepressants, in particular, are associated with side effects such a weight gain and anticholinergic effects, which may make them difficult for patients to tolerate long-term. 

Like some other antidepressants and lithium, the MAOIs can also cause weight gain. Because they do not affect cholinergic receptors, they produce less constipation, dry mouth, and blurred vision, typically associated with the tricyclics. MAOIs do produce some similar adverse effects, particularly urinary hesitancy, possibly because... 

FIGURE 6-30. Side effects of the tricyclic antidepressants—part 1. In this diagram, the icon of the TCA is shown with its antihistamine (HI) portion inserted into histamine receptors, causing the side effects of weight gain and drowsiness. 

Fluoxetine causes weight loss, in contrast to tricyclic antidepressants (417). In one study there was a mean fall in weight of 3.88 pounds over 6 weeks compared with a gain of 4.6 pounds with amitriptyline (418). 

Trimipramine is a sedating tricyclic antidepressant that has been used as a hypnotic (1) it shares this activity with other drugs of its class, notably amitriptyline, dosulepin, doxepin, and trazodone, and with the tetracyclics mianserin and mirtazapine. Trimipramine may be preferred for this purpose, since it has less effect on sleep architecture, including REM sleep (2), and has only a modest propensity to produce rebound insomnia in a subset of patients (3). Sedative antidepressants may be particularly appropriate for individuals at risk of benzodiazepine abuse and patients with chronic pain (4). The usual pattern of tricyclic adverse effects, especially antimuscarinic and hypotensive effects and weight gain, can be expected. Some authors, enthusiastic about GABA enhancers, contend that antidepressants are not useful hypnotic alternatives (5). 

Since tricyclic and tetracyclic antidepressants are frequently associated with weight gain, before starting treatment, weigh all patients and determine it the patient is already overweight (BMI 25.0-29.9) or obese (BMI >30)... 

Although very strict dietary and concomitant drug restrictions must be observed to prevent hypertensive crises and serotonin syndrome, the most common side effects of MAOl and tricyclic/tetracyclic antidepressant combinations may be weight gain and orthostatic hypotension... 

Lithium augmentation of antidepressants is a well-established treatment for resistant depression and is usually well tolerated with all classes of antidepressants, although there have been a few reports of the serotonin syndrome with SSRIs (474). It is possible that shared adverse effects could be magnified by combining lithium with various antidepressants (for example tremor, weight gain, gastrointestinal upset). Hyponatremia secondary to the SIADH has been linked to SSRIs and tricyclic antidepressants, especially in elderly patients, and could predispose to lithium toxicity. 

Of the antidepressants, the most likely to cause weight gain are the tricyclics amitriptyline, imipramine and clomipramine, plus mirtazepine. The SSRI, with the possible exception of paroxetine, are unlikely to do so (Zimmermann et al. 2003). 

Answer C. Orthostatic hypotension occurs with both tricyclic antidepressants and phe-nothiazines because both types of drug can block alpha adrenergic receptors in venous beds. Their ability to block M receptors leads to xerostomia (not salivation) and mydriasis (not miosis). THcyclics and phenothiazines also share a common tendency to decrease seizure threshold and cause weight gain (not loss). 

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