Steemit Medicines: Anti depressants, How do they work? - Prozac & Seroxat

beesteem (58)in #science • 7 years ago (edited)

Depression is a common mental disorder. Globally, more than 300 million people of all ages suffer from depression.
There are effective treatments for depression.

The remedy?

Prozac is a medicine that is one of the most prescribed remedies for depression and anxiety disorder. Lot's of people use this medicine, or a similar one. Today, in Steemit Medicines, we study the medicinal chemistry and explain the mechanism of action.

Figure: The chemical structure of Prozac (Fluoxetine)

In the body the Prozac molecule is transformed to an active amine species Seproxetine.

Another well known medicine is Seroxat, which has the following structure:

Structural similarity = structural activity.

As discussed in previous post, medicinal chemists like to mimic molecular structures, because the body can recognize them in the same way. Still small substitutions can have positive effects on bio availability or on selectivity of the drug. That may minimize side effects!

Did you spot the similarity? Medicinal chemistry QUIZ ;-)

Look at the structure in the pictures above in the red dotted box:
If you look at the pictures above you may recognize that they "look alike". Thats true! Several reuptake inhibitors contain an aryloxypropanamine backbone. This structural group combination has potential for high affinity binding to serotonin receptors. More specifically, they target the serotonin re uptake transporters that depends on the specific substitution pattern of the aryloxy ring. Molecules that have a substitution group in the 4' position (like Prozac and Seroxat) are Selective Serotonin Reuptake inhibitors( SSRIs).

Mechanism of action in the brain

It is known that people who suffer low levels of serotonin in brain, may have depressive disorder. Prozac and Seroxat can increase serotine levels: In the brain, messages are passed from a nerve cell to another via a chemical synapse, a small gap between the cells.

In this picture you see depicted the neurons in our brain. The presynaptic cell sends the neurotransmitters including serotonin into that synaptic gap (1). The neurotransmitters are then recognized by receptors on the surface of the recipient postsynaptic cell (2), which upon this stimulation, in turn, relays the happy signal. There is a quite difficult system with neurotransmitter transporters (pumps) to regulate the concentrations. Normally, that works OK.
Depressive people mostly have too low serotonin levels. The above medicines work at step (3) and block the re-uptake of the serotonin, so that the concentration and stimulation of the receptors at (2) continues!

Summary

Anti depressants like Prozac work as inhibitor of the serotonin reuptake receptors in the synapse in brain. They are efficient in increasing the serotonin levels that are required for that happy feeling.