Each SSRI has a unique profile of multiple pharmacologic actions, which explains the differences in their efficacy and tolerabilitythe most potent serotonin reuptake blocker, but has a low selectivity for the serotonin reuptake muscarinic cholinergic receptors (most potent blocker of muscarinic receptors among the SSRIs) histamine H1 receptors nitric oxide synthase cytochrome P450 2D6 the second most potent inhibitor of serotonin reuptake and the second most selective blocker of serotonin over noradrenaline uptake dopamine reuptake (more potent dopamine uptake inhibitor than other SSRIs) All the SSRIs are licensed for major depressive disorder and are considered to be the first-line treatments of depression.
They are prescribed more often for elderly patients than any other psychotropics and are the antidepressant of choice for many practitioners.
All selective serotonin reuptake inhibitors have the same principal mechanism of action.
The first drug in the SSRI class was Prozac (Fluoxetine), which hit the United States market in 1987. Luvox (Fluvoxamine maleate) was the next SSRI FDA approved in December 05, 1994.
However, now its marketing status is "Discontinued".
Certain differences between SSRIs are clinically significant.
Also, SSRIs have very different molecular structures. Zoloft (Sertraline hydrochloride) was the second SSRI to come to market in the United States, and it was approved by the FDA in December 30, 1991. Paxil (Paroxetine hydrochloride) was the third SSRI to come to market in the United States and was approved by the FDA in December 29, 1992. Chemical structure of Paroxetine differs from other SSRIs by having a piperidine ring.
Celexa (Citalopram hydrobromide) was approved by the FDA in July 17, 1998.
Celexa is manufactured by Forest Pharmaceuticals, Inc.The strategy behind rational drug development is to design a new drug that is capable of affecting a specific neural site of action (e.g., uptake pumps, receptors) while avoiding effects on other site of actions.The goal in such development is to produce agents that are more efficacious, safer and better tolerated than older medications.All SSRIs are non-controlled prescription-only medications. Although all SSRI drugs have the same mechanism of action, each SSRI has slightly different pharmacological and pharmacokinetic characteristics.This leads to differences among the SSRIs in their half-lives, clinical activity, side effects, and drug interactions.Research suggests that abnormalities in neurotransmitter activity can affect mood and behavior.