SSRls selective serotonin reuptake

Listing of antidepressants in traditional groupings. Abbreviations TCAs = tricyclic antidepressants MAOls = monoamine oxidase inhibitors SSRls = selective serotonin reuptake inhibitors. 

Conflicting results (i.e., evidence is equivocal) , not investigated sufficiently BZD, benzodiazepines CBT, cognitive-behavioral therapy SSRl, selective serotonin reuptake inhibitors TCA, tricyclic antidepressants. 

The traditional scheme is complicated by the fact that some antidepressants exhibit characteristics of more than one class. For example, clomipramine, a tricyclic antidepressant (TCA) with side effects and toxicity similar to other TCAs, works more like the selective serotonin reuptake inhibitors (SSRls). Similarly, venlafaxine and duloxetine, which are usually grouped with the atypical antidepressants, have a side effect and safety profile comparable to the SSRls. Although a classihcation system based on mechanism of action offers some advantage (see Table 3.7), even this scheme is limited by the fact that antidepressants that work in the same way may have widely divergent side effect and safety profiles. In the following discussion, the traditional classification system is adopted. Although fraught with problems and inconsistencies. 

Bouman WP Pinner G, Johnson H. Incidence of selective serotonin reuptake Inhibitor (SSRl) induced hyponatraemia due to the syndrome of inappropriate antidiuretic hormone (SIADH) secretion in the elderly. Int J Gerlatr Psychiatry 1998 13 12-15. 

Serotonin is removed from the synapse by a high-affinity serotonin uptake site [(4) in Fig. 2.6] that is capable of transporting serotonin in either direction, depending on its concentration. The serotonin transporter is blocked by selective serotonin reuptake inhibitors (SSRls) as well as by tricyclic antidepressants. 

Clear abnormalities of the dopamine system have not been identified in the periphery or the brain of OCD patients. Nevertheless, repetitive stereotypies and OCD-like behaviors can be produced in humans by the administration of exogenous D2 agonist or stimulants, which suggests that the dopaminergic system may be involved in some way in OCD. Conversely, antipsy-chotics can be used adjunctively in the treatment of selective serotonin reuptake inhibitor (SSRl)-resistant OCD patients with a definite benefit in a significant proportion of patients. 

A countrywide study based on the national medicinal preparations register in Denmark showed that in 1997, 0.3% of the group aged 0-19 years was under treatment with either antipsychotics, psychostimulants, or antidepressants (Sorensen, 1998). The largest use was found among those aged 16-18 years, for whom selective serotonin reuptake inhibitor (SSRl) preparations comprised 90% of the antidepressants. 

Virtually all studies on the monotherapy of PMD have employed TCAs. At this time, no data exist on the utility of the selective serotonin reuptake blockers [SSRls], serotonin type 2 antagonists [trazodone or nefazodone], or other newer agents such as venlafaxine in the monotherapy of PMD. 

The selective serotonin reuptake inhibitors (SSRls) have received increased attention in the treatment of anxiety disorders. With the recent Food and Drug Administration (FDA) approval of fluoxetine and fluvoxamine in the treatment of obsessive-compulsive disorder, it has been made clear that this... 

Hyttel J Pharmacological characterization of selective serotonin reuptake inhibitors (SSRls). Int Clin Psychopharmacol 9 (suppl l) 19-26, 1994 Hytell J, Larsen J-J Serotonin-selective antidepressants. Acta Pharmacol Toxicol 56 (suppl 1) 146-153, 1985... 

Other clinical uses Tricyclic drugs are also used in the treatment of bipolar affective disorders, acute panic attacks, phobic disorders (compare with alprazolam Chapter 22), enuresis, and chronic pain states. Clomipramine and the selective serotonin reuptake inhibitors, including fiuvoxamine, are effective in obsessive-compulsive disorders. SSRls are also effective in patients who suffer from panic attacks, social phobias, bulimia, and premenstrual syndrome (PMS) and may also be useful in the treatment of alcohol dependence. Bupropion is used for management of patients attempting to withdraw from nicotine dependence. 

A psychologically normal 55-year-old man had a large acoustic neuroma removed from his hrain. Following operation, he became so violently angry and aggressive that he was unahle to work, and, according to his wife, became impossible to live with. After six months of misery, he was begun on treatment with a selective serotonin reuptake inhibitor (SSRl) to increase the levels of the neurotransmitter, serotonin, in his brain. After two weeks of treatment, he was able to return to his normal preoperative mental state, and go back to work. 

Since their introduction in the 1980s, selective serotonin reuptake inhibitors (SSRls) such as paroxetine, fluoxetine, and citalopram have enjoyed tremendous clinical and commercial success due to their improved safety profile when compared with first-generation tricyclic antidepressants like imipramine. Nevertheless, they still display several side effects including gastrointestinal distress, anxiety, insomnia, weight gain, and sexual dysfunction. Like other current antidepressants. 

A study of maca in patients taking selective serotonin reuptake inhibitors (SSRl) indicated no changes in SSRI efficacy (Dording et i. 2008). 

As discussed above, the analgesic effect of codeine depends greatly on its abihty to be metabolized to morphine. In patients in whom large amounts of codeine have been administered without relief, the possibility of a polymorphism of the CYP2D6 enzyme must be considered. Medications that inhibit CYP2D6 may reduce or even completely block the conversion of codeine to morphine. These include selective serotonin reuptake inhibitors (SSRls), cimetidine, and antidepressants such as buproprion. On the other hand agents that induce CYP450 isozymes, such as rifampin and dexamethasone, increase the conversion rate and increase the risk of adverse events. 

Fig. 7.1 Some representatives of selective serotonin reuptake inhibitors (SSRls)...

Serotonin mediates many central and peripheral physiological functions, including contraction of smooth muscle, vasoconstriction, food intake, sleep, pain perception, and memory, a consequence of it acting on several distinct receptor types. Although 5-HT may be metabolized by monoamine oxidase, platelets and neurons possess a high-affinity mechanism for reuptake of 5-HT. This mechanism may be inhibited by the widely prescribed antidepressant drugs termed selective serotonin re-uptake inhibitors (SSRl), e.g. fluoxetine (Prozac ), thereby increasing levels of 5-HT in the central nervous system. 

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. 

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