SSRI Drugs: Classification, Types, and Uses

What is the classification of SSRI drug? 

SSRI is a class of antidepressants that work by blocking the reabsoprtion of serotonin in the body thereby causing high level of serotonin in the body. SSRIs are the most common antidepressants prescribed for treating mood disorders such as anxiety and depression ( Ciraulo, Shader, Greenblatt, 2011) . Unlike other class of antidepressants such as SSNRs thy affect other transmitters, SSRIs class of drugs affects only serotonin transporter. 

Give a brief history of how SSRIs were discovered? 

These drugs have contributed immensely to the advances of antidepressants by revolutionizing the treatment of depression among other mood disorders including panic disorders, obsessive compulsive disorder, post traumatic disorder, social anxiety disorder, anorexia and premenstrual dysphoric disorder. There was limited treatment for psychiatric disorders before the discovery of SSRIs drugs. Today, there are dozens of antidepressants drugs in the market for treating depression and other mood disorders. 

MAOIs and TCAs dates back to early 1950s; these were the first antidepressants developed to treat depression. The use of this drug was limited due to undesirable side effects due to their non selective pharmacological effects. This led to discovery of SSRIs with similar effectiveness, but with fewer side adverse effects. It was a significant medicinal discovery in past few decades and the first discovery to confirm that inhibiting the re-uptake of neurotransmitter is an important therapeutic principle. It also established the pathophysiological role for 5-HT in the spectrum of anxiety disorders and affective illness. 

The first SSRI drug to be marketed was zimedine, but it was withdrawn from the market in 1983 due associated cases of Guillain Barre Syndrome . As a result a number of non tricyclic SSRIs drugs were discovered including Fluoxetine which was approved by FDA in 1987 paving the way for development of a new generation of SSRIs drugs ( Perez-Caballero, Torres-Sanchez, Bravo, Mico & Berrocoso, 2014). 

How do they affect the body? 

They work by increasing the amount of serotonin in the brain by blocking the reuptake of serotonin in the brain. Serotonin is a type of neurotransmitters responsible for carrying signals between the cells of the brain. This class of drug is selective because they mainly affect serotonin and not other types of neurotransmitters. 

Important information to give to the patient 

Information on the safety of SSRIs drugs is necessary prior to using these antidepressants. Generally, SSRIs are safe for most people, but may also cause problems in some situation. For instance, high doses of citalopram can lead to risky abnormal heart rhythms. It is therefore advisable to avoid a dosage of more than 40mg per day and a maximum of 20mg is recommended for persons over 60 years ( Mayo Clinic, 2016) . 

Some SSRIs are not suitable for pregnant and breastfeeding women because they can harm the baby ( Hviid, Melbye & Pasternak, 2013) . People using these drugs should consult their doctor if they consider getting pregnant. Information on drug interaction is also critical before a person starts to use SSRIs drugs. It is important to discuss with the doctor about other medications, prescriptions, supplements and herbs being taken by the patient to avoid possible interactions. This is because some SSRIs can react dangerously with some medications or herbal supplements. 

There is also a possibility of causing serotonin syndrome especially when they are combined with other drugs such as headache or pain relievers or herbal supplements that raise the level of serotonin in the brain. However, it is rare for any single antidepressant to cause high level of accumulation of serotonin in the body. Serotonin syndrome is characterized by sweating, anxiety, agitation, tremors, confusion, and lack of coordination, restlessness and rapid heart rate. It is important to seek immediate medical attention when these symptoms are experienced. 

General side effects common with SSRIs drugs 

All SSRIs drugs work in similar manner and they generally have similar side effects on the patients. Even though most side effects diminish within a few weeks of treatment, some are intolerable in some people and could lead to the prescription of a different drug. However, some patient may not experience any side effects after using these drugs. Furthermore, if a patient cannot tolerate one type of SSRI, they can still tolerate a different type of SSRI drug because they have different chemical make up ( Mayo Clinic, 2016) . The following are general side effect of SSRIs drugs: 

Nausea 

Drowsiness 

Dry mouth 

Insomnia 

Dizziness 

Nervousness, restlessness or agitation 

Blurred vision 

Headache 

Sexual problems such as erectile dysfunction, difficult reaching organism and reduced sexual desire 

These drugs should be used with food to reduce the risk of side effects such as nausea and dizziness. It is also advisable to take SSRIs at bedtime to reduce the risk of dizziness, nausea, drowsiness and restlessness (Bet eta al, 2013). 

Dangers associated with SSRIs drugs 

The risk of committing suicide is the primary danger associated with the use of SSRIs drugs. Even though they are generally safe, these drugs are required by FDA to carry the strictest warnings for prescriptions. These drugs are known to increase the suicidal behavior and thoughts among some children, teenagers and young adults aged below 25 years particularly in the first few weeks of use or changing the dose ( Mayo Clinic, 2016) . Therefore, close monitoring is recommended to check for unusual behavior or increased depression in these groups of people. 

Five of the more common SSRIs Drugs 

The following common SSRIs drugs approved by FDA for treating depression and other types of mood disorders: 

Citalopram (Celexa) 

Fluoxetine (Prozac) 

Vilazodone (Viibryd) 

Sertraline (Zoloft) 

Escitalopram (Lexapro) 

References 

Ciraulo, D.A.; Shader, R.I.; Greenblatt, D.J. (2011). Clinical Pharmacology and Therapeutics of Antidepressants.   Pharmacotherapy of Depression, Second Edition : 33–124.    doi : 10.1007/978-1-60327-435-7_2 . ISBN    978-1-60327-434-0 . 

Hviid, A., Melbye, M., & Pasternak, B. (2013). Use of selective serotonin reuptake inhibitors during pregnancy and risk of autism.    New England Journal of Medicine , 369 (25), 2406-2415. 

Mayo Clinic. (2016). Selective serotonin reuptake inhibitors (SSRIs). Rertrieved from www.mayoclinic.org/diseases-conditions/depression/in-depth/ssris/art-20044825?pg=2 

Perez-Caballero, L., Torres-Sanchez, S., Bravo, L., Mico, J. A., & Berrocoso, E. (2014). Fluoxetine: a case history of its discovery and preclinical development.    Expert opinion on drug discovery ,    9 (5), 567-578.