This leads to differences among the SSRIs in their half-lives, clinical activity, side effects, and drug interactions.
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, SSRIs differ in their potency and selectivity in inhibiting serotonin reuptake and many of them have important effects on other transporters and receptors.
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.
SSRIs are called selective because they seem to affect serotonin significantly more than other neurotransmitters.
Thus, the medications work by allowing the body to make the best use of the reduced amounts of serotonin that it has at the time.