Selective serotonin reuptake inhibitors (SSRIs) refer to medications that are originally developed to act as antidepressants; they treat depression by increasing levels of serotonin in the brain. Serotonin is one of the neurotransmitters that carry signals between brain nerve cells (neurons).
SRIs block the reabsorption (reuptake) of serotonin into the pre-synaptic neurons. This makes more serotonin available to improve the transmission of messages between neurons. Serotonin will also spend more time at the synaptic cleft before they get reabsorbed into the pre-synaptic neuron.
SSRIs are called selective because they mainly affect serotonin, not other neurotransmitters. The other neurotransmitters that are commonly implicated in depression include norepinephrine and dopamine.
It is interesting that SSRIs, apart from treating depression, can also be used to treat anxiety disorders, obsessive-compulsive disorder and impulse control disorders. The following SSRIs are available in Singapore:
- Escitalopram (Lexapro)
- Fluoxetine (Prozac)
- Paroxetine (Seroxat)
- Sertraline (Zoloft)
- Fluvoxamine (Faverin)
The main difference in the various SSRIs is their potencies at blocking serotonin reuptake and in how quickly your body metabolizes or gets rid of the drug. Many patients do not experience side effects from the medicines; they do tolerate them quite well. Others may report having these side effects:
- nausea or vomiting
- loose stools
- dry mouth
- disturbed sleep
- agitation or restlessness
- reduced sexual desire
- difficulty reaching orgasm or inability to maintain an erection (erectile dysfunction)
- changes in appetite, leading to weight loss or weight gain
If you do not tolerate one SSRI well, you may tolerate another one well. It may take a while before your doctor finds out which medication suits you the best.