Selective serotonin reuptake inhibitors escitalopram

Figure 5. The effect of the selective serotonin reuptake inhibitor, escitalopram, on firing activity of norepinephrine neurons. Norepinephrine neurons exhibit tonic-phasic firing activity of 1.5-3.0 Hz, with small (2-3/min) number of short burst ( ). Escitalopram inhibits the firing activity of norepinephrine...

Venlafaxine extended release, duloxetine, paroxetine, and escitalopram are FDA approved for treatment of GAD. Sertraline is also effective. Acute response and remission rates are approximately 65% and 30%, respectively. Imipramine may be used when patients fail to respond to selective serotonin reuptake inhibitors (SSRIs). In one trial, diazepam, trazodone, and imipramine had greater anxiolytic activity than placebo. 

The selective serotonin reuptake inhibitors (SSRIs) represent a chemically diverse class of agents that have as their primary action the inhibition of the serotonin transporter (SERT) (Figure 30-3). Fluoxetine was introduced in the United States in 1988 and quickly became one of the most commonly prescribed medications in medical practice. The development of fluoxetine emerged out of the search for chemicals that had high affinity for monoamine receptors but lacked the affinity for histamine, acetylcholine, and adrenoceptors that is seen with the tricyclic antidepressants (TCAs). There are currently six available SSRIs, and they are the most common antidepressants in clinical use. In addition to their use in major depression, SSRIs have indications in GAD, PTSD, OCD, panic disorder, PMDD, and bulimia. Fluoxetine, sertraline, and citalopram exist as isomers and are formulated in the racemic forms, whereas paroxetine and fluvoxamine are not optically active. Escitalopram is the S enantiomer of citalopram. As with all antidepressants,... 

These selective serotonin reuptake inhibitors (SSRIs) include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), fluvoxamine (Luvox), citalopram (Celexa), and, most recently, escitalopram (Lexapro see the appendix). These drugs block the removal of the neurotransmitter serotonin from the synaptic cleft. A number of other antidepressants are potent nonselective serotonin reuptake inhibitors (NSRIs). These include the atypical venlafaxine (Effexor) and the tricyclic clomipramine (Anafra-nil). Nefazodone (Serzone) has been withdrawn from the market due to liver damage. 

Selective serotonin reuptake inhibitors (SSRIs) Escitalopram (Lexapro) Eluoxetine (Prozac) Paroxetine (Paxil) Sertraline (Zoloft)... 

Escitalopram is a selective serotonin reuptake inhibitor that inhibits the CNS neuronal nptake of serotonin, potentiating serotonergic activity. It is indicated in the major depressive disorders and generalized anxiety. 

Selective serotonin reuptake inhibitors - citalopram/escitalopram... 

Fig. 22.21. Structures of the selective serotonin reuptake inhibitors (SSRIs) fluoxetine, fluvoxamine, paroxetine, sertraline, and escitalopram.

Several selective serotonin reuptake inhibitors (SSRIs), including escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline (Fig. 22.21), are effective as first-line treatment cf seme anxiety disorders, with the purported advantage that they lack the addictive preperties cf benzediazepines (135). Specifically, the SSRIs have been shown to be effective in obsessive-ccmpulsive diserder (139), panic disorder (140), and social phobia (141). The mechanism of action of these agents in anxiety may differ with their role in the treatment of depression however,... 

Another example of a chiral drug is escitalopram, which is an antidepressant acting as a selective serotonin reuptake inhibitor. It is optically active, having the S-configuration shown in stmcture 10.30. It is a follow-up to the marketed racemic mixture of the same stmcture known as citalopram, and is more active than the racemic mixture. 

SSRIs (Selective serotonin reuptake inhibitors) Citalopram, Escitalopram, Femoxetine, Fluoxetine, Fluvoxamine, Paroxetine, Sertraline... 

In a study on the effects of maca for sexual dysfunction induced by selective serotonin reuptake inhibitors (SSRI), patients who were stable on an SSRI (patients were taking escitalopram, citalopram, sertraline, venlafexine, fluoxetine, paroxetine, duloxetine, or fluvoxamine) were orally administered 1.5 or 3 g of maca daily for 12 weeks. No adverse effects of maca, including effects on SSRI efficacy, were reported, and patients in the high dose group had a modest improvement in depression (Dording et al. 2008). 

Yang EIM, Lee WK, Chang SW, Chiu NM, Huang JH. Escitalopram-induced word finding difficulty. Gen Hosp Psychiatry 2013 35(1) 103 e5-6. Rohrs S, Geiser F, Conrad R. Citalopram-induced subacute cutaneous lupus erythematosus - first case and review concerning photosensitivity in selective serotonin reuptake inhibitors. Gen Hosp Psychiatry 2012 34(5) 541-5. 

Citalopram is a racemic bicyclic phthalane derivative and is a highly selective serotonin re-uptake inhibitor with minimal effects on noradrenaline and dopamine neuronal reuptake. Inhibition of 5-HT re-uptake by citalopram is primarily due to escitalopram, the active S-enantiomer of citalopram (1). One would expect escitalopram to be twice as potent as citalopram but otherwise not to differ significantly from the racemic mixture. However, escitalopram is marketed as being more efficacious than citalopram because, it is argued, the inactive R-isomer present in the racemate actually inhibits binding of the S-enantiomer to its site of action, the serotonin transporter. In some, but not all, clinical trials escitalopram has been statistically superior to citalopram in terms of speed of onset of therapeutic action and improvement on depression rating scales. The clinical significance of these differences is debatable (2). 

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