Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.
Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains three rings of atoms. Tetracyclic antidepressants (TeCAs), which contain four rings of atoms, are a closely related group of antidepressant compounds.
Escitalopram, sold under the brand names Lexapro and Cipralex, among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. Escitalopram is mainly used to treat major depressive disorder and generalized anxiety disorder. It is taken by mouth, available commercially as an oxalate salt exclusively.
Citalopram, sold under the brand name Celexa among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is used to treat major depressive disorder, obsessive compulsive disorder, panic disorder, and social phobia. The antidepressant effects may take one to four weeks to occur. It is typically taken orally. In some European countries, it is sometimes given intravenously to initiate treatment, before switching to the oral route of administration for continuation of treatment. It has also been used intravenously in other parts of the world in some other circumstances.
Serotonin–norepinephrine reuptake inhibitors (SNRIs) are a class of antidepressant medications used to treat major depressive disorder (MDD), anxiety disorders, social phobia, chronic neuropathic pain, fibromyalgia syndrome (FMS), and menopausal symptoms. Off-label uses include treatments for attention-deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder (OCD), and migraine prevention. SNRIs are monoamine reuptake inhibitors; specifically, they inhibit the reuptake of serotonin and norepinephrine. These neurotransmitters are thought to play an important role in mood regulation. SNRIs can be contrasted with the selective serotonin reuptake inhibitors (SSRIs) and norepinephrine reuptake inhibitors (NRIs), which act upon single neurotransmitters.
Antidepressant discontinuation syndrome, also called antidepressant withdrawal syndrome, is a condition that can occur following the interruption, reduction, or discontinuation of antidepressant medication following its continuous use of at least a month. The symptoms may include flu-like symptoms, trouble sleeping, nausea, poor balance, sensory changes, akathisia, intrusive thoughts, depersonalization and derealization, mania, anxiety, and depression. The problem usually begins within three days and may last for several weeks or months. Psychosis may rarely occur.
Fluoxetine, sold under the brand name Prozac, among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is used for the treatment of major depressive disorder, obsessive–compulsive disorder (OCD), anxiety, bulimia nervosa, panic disorder, and premenstrual dysphoric disorder. It is also approved for treatment of major depressive disorder in adolescents and children 8 years of age and over. It has also been used to treat premature ejaculation. Fluoxetine is taken by mouth.
A serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI), also known as a triple reuptake inhibitor (TRI), is a type of drug that acts as a combined reuptake inhibitor of the monoamine neurotransmitters serotonin, norepinephrine, and dopamine. It does this by concomitantly inhibiting the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT), respectively. Inhibition of the reuptake of these neurotransmitters increases their extracellular concentrations and, therefore, results in an increase in serotonergic, adrenergic, and dopaminergic neurotransmission. The naturally-occurring and potent SNDRI cocaine is widely used recreationally and often illegally for the euphoric effects it produces.
A serotonin reuptake inhibitor (SRI) is a type of drug which acts as a reuptake inhibitor of the neurotransmitter serotonin 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. It is a type of monoamine reuptake inhibitor (MRI); other types of MRIs include dopamine reuptake inhibitors and norepinephrine reuptake inhibitors.
Nisoxetine, originally synthesized in the Lilly research laboratories during the early 1970s, is a potent and selective inhibitor for the reuptake of norepinephrine (noradrenaline) into synapses. It currently has no clinical applications in humans, although it was originally researched as an antidepressant. Nisoxetine is now widely used in scientific research as a standard selective norepinephrine reuptake inhibitor. It has been used to research obesity and energy balance, and exerts some local analgesia effects.
Reuptake inhibitors (RIs) are a type of reuptake modulators. It is a drug that inhibits the plasmalemmal transporter-mediated reuptake of a neurotransmitter from the synapse into the pre-synaptic neuron. This leads to an increase in extracellular concentrations of the neurotransmitter and an increase in neurotransmission. Various drugs exert their psychological and physiological effects through reuptake inhibition, including many antidepressants and psychostimulants.
Desmethylcitalopram is an active metabolite of the antidepressant drugs citalopram (racemic) and escitalopram. Like citalopram and escitalopram, desmethylcitalopram functions as a selective serotonin reuptake inhibitor (SSRI), and is responsible for some of its parents' therapeutic benefits.
Desmethylsertraline (DMS), also known as norsertraline, is an active metabolite of the antidepressant drug sertraline. Like sertraline, desmethylsertraline acts as a monoamine reuptake inhibitor, and may be responsible for some of its parent's therapeutic benefits; however, the effects of DMS's main activity of increasing serotonin levels via binding to the serotonin transporter appears to be negligible as in vivo testing showed no measurable change in brain activity despite a nearly 20-fold increase in DMS blood levels compared to the EC50 (i.e. the amount required to achieve the desired effect in 50% of the population) of its parent drug sertraline. DMS is significantly less potent relative to sertraline as a serotonin reuptake inhibitor (Ki = 76 nM vs. 3 nM, respectively), but conversely, is more balanced as a monoamine reuptake inhibitor (5-HT (Ki) = 76 nM; NE (Ki) = 420 nM; DA (Ki) = 440 nM), which has the effective result of DMS contrarily behaving as a serotonin-norepinephrine-dopamine reuptake inhibitor (SNDRI), with about 5.5-fold preference for inhibiting serotonin reuptake relative to catecholamine reuptake.
Didesmethylcitalopram is an active metabolite of the antidepressant drug citalopram (racemic). Didesmethylescitalopram is an active metabolite of the antidepressant escitalopram, the S-enantiomer of citalopram. Like citalopram and escitalopram, didesmethyl(es)citalopram functions as a selective serotonin reuptake inhibitor (SSRI), and is responsible for some of its parents' therapeutic benefits.
Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions.
A monoamine reuptake inhibitor (MRI) is a drug that acts as a reuptake inhibitor of one or more of the three major monoamine neurotransmitters serotonin, norepinephrine, and dopamine by blocking the action of one or more of the respective monoamine transporters (MATs), which include the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT). This in turn results in an increase in the synaptic concentrations of one or more of these neurotransmitters and therefore an increase in monoaminergic neurotransmission.
Selective serotonin reuptake inhibitors, or serotonin-specific re-uptake inhibitor (SSRIs), are a class of chemical compounds that have application as antidepressants and in the treatment of depression and other psychiatric disorders. SSRIs are therapeutically useful in the treatment of panic disorder (PD), posttraumatic stress disorder (PTSD), social anxiety disorder, obsessive-compulsive disorder (OCD), premenstrual dysphoric disorder (PMDD), and anorexia. There is also clinical evidence of the value of SSRIs in the treatment of the symptoms of schizophrenia and their ability to prevent cardiovascular diseases.
PPPA, or 3-phenoxy-3-phenylpropan-1-amine, is a drug which is described as an antidepressant. It was derived by Eli Lilly from the antihistamine diphenhydramine, a diphenylmethane derivative with additional properties as a selective serotonin reuptake inhibitor (SSRI), and has been the basis for the subsequent discovery of a number of other antidepressant drugs.
A neurosteroidogenesis inhibitor is a drug that inhibits the production of endogenous neurosteroids. Neurosteroids include the excitatory neurosteroids pregnenolone sulfate, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEA-S), and the inhibitory neurosteroids allopregnanolone, tetrahydrodeoxycorticosterone (THDOC), and 3α-androstanediol, among others. By inhibiting the synthesis of endogenous neurosteroids, neurosteroidogenesis inhibitors have effects in the central nervous system.
Selective norepinephrine reuptake inhibitors (sNRIs) are a class of drugs that have been marketed as antidepressants and are used for various mental disorders, mainly depression and attention-deficit hyperactivity disorder (ADHD). The norepinephrine transporter (NET) serves as the fundamental mechanism for the inactivation of noradrenergic signaling because of the NET termination in the reuptake of norepinephrine (NE). The selectivity and mechanism of action for the NRI drugs remain mostly unresolved and, to date, only a limited number of NRI-selective inhibitors are available. The first commercially available selective NRI was the drug reboxetine (Edronax), developed as a first-line therapy for major depressive disorder. Atomoxetine (Strattera) is another potent and selective NRI which is also effective and well tolerated for the treatment of ADHD in adults; it may also be a new treatment option for adults with ADHD, particularly for those patients at risk of substance abuse.
