Serotonin reuptake inhibitor

A serotonin reuptake inhibitor (SRI) is a type of drug that acts as a reuptake inhibitor for the neurotransmitter serotonin (5-hydroxytryptamine [5-HT]) by blocking the action of the serotonin transporter (SERT). This in turn leads to increased extracellular concentrations of serotonin and, therefore, an increase in serotonergic neurotransmission.

SRIs are not synonymous with selective serotonin reuptake inhibitors (SSRIs), as the latter term is usually used to describe the class of antidepressants of the same name, and, because SRIs, unlike SSRIs, can be either selective or nonselective in their action. For example, cocaine, which nonselectively inhibits the reuptake of serotonin, norepinephrine, and dopamine, can be called an SRI, but not an SSRI.

Indications

SRIs may be used in the clinical treatment of mood disorders such as major depressive disorder (MDD), dysthymia, and bipolar disorder (BD) as antidepressants, anxiety disorders such as generalized anxiety disorder (GAD), social phobia (SP) also known as social anxiety disorder (SAD), obsessive-compulsive disorder (OCD), and panic disorder (PD) as anxiolytics, post-traumatic stress disorder (PTSD), body dysmorphic disorder (BDD), eating disorders like anorexia nervosa and bulimia nervosa, and certain personality disorders such as borderline personality disorder (BPD), as well as chronic pain, neuralgia or neuropathic pain, and fibromyalgia as analgesics (see duloxetine, milnacipran, and bicifadine), irritable bowel syndrome (IBS) as gastroprokinetic agents, premature ejaculation (PE) (see dapoxetine), drug addiction as anticraving agents, and obesity for anorectic or weight loss purposes (see sibutramine).

Effects

General

SRIs can induce a wide range of psychological and physiological effects, including the following:

It should be noted, however, that many of these effects are dependent on whether the administration of the SRI is acute or chronic. As an example, acute ingestion typically does not result in a mood lift, and chronic administration usually does not result in any sort of psychedelia whatsoever. Additionally, many of these properties are also dependent on whether the SRI in question is capable of crossing the blood-brain-barrier (BBB). Those that do not will only produce peripheral effects.

Overdose

At very high doses characterized by overdose, serotonin syndrome may develop, resulting in symptoms including the following:

List of SRIs

See also

• Serotonergic
• Reuptake inhibitor
• Selective serotonin reuptake inhibitor (SSRI)
• Norepinephrine reuptake inhibitor (NRI)
• Serotonin-norepinephrine reuptake inhibitor (SNRI)
• Dopamine reuptake inhibitor (DRI)
• Norepinephrine-dopamine reuptake inhibitor (NDRI)
• Serotonin-norepinephrine-dopamine reuptake inhibitor (SNDRI)

References