Selective norepinephrine reuptake inhibitors side effects

Side effects, mainly due to serotonin reuptake inhibition include G1 upset, nervousness, and sexual dysfunction. SSRls are associated with an increased risk of falls. Hyponatraemia due to SIADH is an uncommon, but important side effect in elderly patients. Selective serotonin and norepinephrine reuptake inhibitors (S SNRls) such as venlafaxine and duloxetine are also useful in older patients. Other heterocyclic antidepressants of importance in older patients because of relative safety include bupro-prion and mirtazepine. They are reserved for patients with resistance to or intolerance of SSRls. Currently, trazodone is used mostly for sleep disturbance in depression in doses of 50-100 mg at bedtime. The monoamine oxidase inhibitors phenelzine. 

This diverse collection has been grouped together mostly because they do not operate as selective serotonin reuptake inhibitors. Instead, each one interacts differently with neurotransmitters that are tied to depression serotonin, norepinephrine, or dopamine. For instance, one of the more popular non-SSRIs, Effexor (venlafaxine), selectively inhibits the uptake of serotonin and norepinephrine, acting on the same molecular machinery as tricyclic antidepressants (TCAs). But, in contrast to TCAs, Effexor shows no affinity for other neurotransmitter receptors and thus has far fewer side effects than the... 

The selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment of depression in the elderly. Compared with tricyciic antidepressants (TCAs), they are much safer in overdose and, for the most part, their side-effects are better tolerated. The antidepressants that have been shown, in controlled studies, to be effective in geriatric major depression are the SSRIs fluoxetine, paroxetine, and sertraline, the TCAs clomipramine and nortriptyline, and the serotonin and norepinephrine reuptake inhibitor (SNRi) venlafaxine. Given that most antidepressants are effective in the elderly, the choice of drug is based on its side-effect profile and its potential to interact with other medications. 

Tricyclics modify peripheral sympathetic effects in two ways through blockade of norepinephrine reuptake at neuroeffector junctions and through alpha adrenoceptor blockade. Sedation and atropine-like side effects are common with tricyclics, especially amitriptyline. In contrast to sedative-hypnotics, tricyclics lower the threshold to seizures. The answer is (B). Selective serotonin reuptake inhibitors cause sexual dysfunction in some patients, with changes in libido, erectile dysfunction, and anorgasmia. Tricyclic antidepressants may also decrease libido or prevent ejaculation. Of the heterocyclic antidepressants bupropion is the least likely to affect sexual performance. The drug is also used in withdrawal from nicotine dependence. The answer is (B). 

Serotonin-norepinephrine reuptake inhibitors (SNRIs) (e.g. duloxetine, venlafaxine and desvenlafax-ine) inhibit the reuptake of both serotonin and norepinephrine and are referred to as dual inhibitors or selective serotonin norepinephrine inhibitors . The SNRIs lack of anticholinergic side effects results in a distinct advantage over traditional TCAs [13,77,78]. For example, duloxetine is a potent, balanced inhibitor of serotonin and norepinephrine reuptake [79]. Venlafaxine inhibits serotonin reuptake at lower dosages and inhibits both serotonin and norepinephrine reuptake at higher dosages [70,80]. 

Many inhibitors of the amine transporters for norepinephrine, dopamine, and serotonin are used clinically. Although specificity is not absolute, some are highly selective for one of the transporters. Many antidepressants, particularly the older tricyclic antidepressants can inhibit norepinephrine and serotonin reuptake to different degrees. This may lead to orthostatic tachycardia as a side effect. Some antidepressants of this class, particularly imipramine, can induce orthostatic hypotension presumably by their clonidine-like effect or by blocking 04 receptors, but the mechanism remains unclear. 

Reboxetine. Reboxetine (21) is a norepinephrine-selective reuptake inhibitor that lacks affinity for most of the monoamine receptors. It thus does not exhibit the typical side-effect profile of the tricyclics. Nevertheless, side effects include increased sweating, postural hypotension (leading to dizziness), dry mouth, constipation, blurred vision, impotence, and dysuria. Tachycardia and urinary retention have also been reported (59). There is no evidence of cardiotoxicity and sexual dysfunction seems to be rare. In contrast to some of the earlier tricyclics that are sedative, reboxetine is nonsedating and can cause insomnia (60,61).. 

D. Selective norepinephrine and serotonin reuptake inhibitors. Both Venlafaxine and Duloxetine have shown significant higher effect than placebo in the treatment of pain in diabetic patients and both compounds are being used with increasing frequency in these patients. Duloxetine is a more potent inhibitor than Venlafaxine and seems from clinical studies to be more efficacious. Doses tested in trials are 60 and 120 mg/day and side effects include nausea, somnolence, dizziness, dry mouth and decreased appetite. 

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