Prozac Fluoxetine action

A breakthrough in the treatment of major depression was the discovery of fluoxetine, marketed as Prozac. Fluoxetine has a mechanism of action similar to that of imipramine with an important exception. It is a selective serotonin reuptake inhibitor, an SSRI. This strongly suggests that, in some sense, the symptoms of major depression result from a deficit in serotonin specifically. By inhibiting its reuptake from the synapse, the activity of serotonin is enhanced. Two other important drugs for major depression, sertraline (Zoloft) and paroxetine (Paxil), among several others,... 

The older generation of drags are less desirable than the new selective serotonin reuptake inhibitors, because they have many actions in the body other than their antidepressant effect. Prozac (fluoxetine hydrochloride) is among this group. Other trade names in this group are Celexa, Paxil, and Zoloft. 

The mechanism of action of most of the miscellaneous antidepressants is not clearly understood. Examples of this group of drugs include fluoxetine (Prozac) and bupropion (Wellbutrin). 

Tricyclic drugs have, as the name implies, a three-ring structure, and interfere with reuptake of norepinephrine and/or serotonin into axon terminals. Tricyclic drugs include imipramine (Tofranil), amitriptyline (Elavil), clomipramine (Anafranil), and nortriptyline (Pamelor, Aventil). Tricyclics have the occasional but unfortunate cardiovascular side effects of arrhythmia and postural hypotension. Newer, nontricyclic antidepressants have been developed that are collectively referred to as SSRIs. These have a potent and selective action on serotonin, and lack the cardiovascular side effects of the tricyclics. These include fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), and fluvoxamine (Luvox). A fifth SSRI, citalopram (Celexa) has been used in Europe and has recently been approved in the United States. Venlafaxine (Effexor) blocks reuptake of norepinephrine and serotonin, while bupropion (Wellbutrin) acts on both dopamine and norepinephrine. 

A growing number of drugs are used that affect the many neurotransmitters in the brain benzodiazepines and others act on GABAergic transmission antidepressants, such as monoamine oxidase inhibitors and tricyclic antidepressants, are thought to increase the concentration of transmitter amines in the brain and so elevate mood—these will also act at peripheral nerve terminals, so interactions with them are a combination of peripheral and central actions. Levodopa (L-dopa) increases central as well as peripheral dopamine, and the newer class of psychoactive drugs, the selective serotonin reuptake inhibitors (SSRIs) of which the ubiquitous fluoxetine (Prozac) is best known, act in a similar way on serotonergic pathways. 

The most widely known SSRIs are fluoxetine hydrochloride (4, Prozac , Lilly), sertraline hydrochloride (5, Zoloft , Pfizer) and paroxetine hydrochloride (6, Paxil , GSK). Fluoxetine (4, Prozac ) was the first SSRl approved and effected a revolutionary change in the treatment of depression. In 2000, it was the most widely prescribed antidepressant drug in the United States with worldwide sales of 2.58B. Sertraline (5, Zoloft ) has been available in the United States since 1992 and had worldwide sales of 2.14B in 2000. Compared to fluoxetine (4), it has a shorter duration of action and fewer CNS activating side-effects such as nervousness and anxiety. Paroxetine (6, Paxil ) generated worldwide sales of 2.35B in 2000 and has a relatively benign side-effect profile, which favors its use with elderly patients. 

Fluoxetine (Prozac /Lilly), paroxetine (Paxil /GlaxoSmithKilne), and sertraline (Zoloft /Pfizer) are selective serotonin reuptake inhibitors (SSRIs) and are useful in the treatment of depression. These agents potentiate the pharmacological actions of the neurotransmitter serotonin by preventing its reuptake at presynaptic neuronal membranes. In addition to its SSRI properties, venlafaxine (EfFexor /Wyeth-Ayerst) also appears to be a potent inhibitor of neuronal norepinephrine reuptake and a weak inhibitor of dopamine reuptake thereby enhancing the actions of these neurotransmitters as well. Venlafaxine is indicated for use in anxiety and depression. 

MR-visible fluorinated compounds that can be measured in the human brain comprise a large number of psychiatric medications including most of the serotonin-specific reuptake inhibitors (SSRIs) such as fluoxetine (Prozac ) [1, 28, 41], as well as pharmaceuticals with mechanisms of action outside the central nervous system such as dexfenfluramine (fen-phen, a serotoninergic anorectic drug) [1, 31]. A recent review [1] covers the impact of MR spectroscopy in psychiatry. 

A mechanism for altering synaptic availability of 5-HT is inhibition of presynaptic reaccumulation of neuronally released 5-HT. Selective serotonin reuptake inhibitors (SSRIs e.g., fluoxetine [PROZAC]) potentiate and prolong the action of 5-HT released by neuronal activity. Effects of 5-HT-active drugs, like the SSRIs, in anxiety and depressive disorders strongly suggest an effect of 5-HT in the neurochemical mediation of these disorders. SSRIs are the most widely used treatment for endogenous depression (see Chapter 17). 

The client with a major depressive disorder taking the selective serotonin reuptake inhibitor (SSRI) fluoxetine (Prozac) calls the psychiatric clinic and reports feeling confused and restless and having an elevated temperature. Which action should the... 

There are several SSRI inhibitors. Their chemical structures are different but they have similar modes of action, namely binding to the SERT. However, they have different pharmacokinetic parameters such as half-life, and differences in adverse effects and drug interactions [54]. Fluoxetine was the first drug of the class, approved in the U.S. in 1987. It is a chiral molecule and the racemic mixture is used as the hydrochloride salt (Prozac , Lilly). It has been approved and marketed in more than 90 countries and used by more than... 

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