Eszopiclone is a nonbenzodiazepine hypnotic, pyrrolopyrazine derivative of the cyclopyrrolone class and is indicated for the short-term treatment of insomnia. While Eszopiclone is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties, it interacts with the gamma-aminobutyric acid-benzodiazepine (GABABZ) receptor complex. Subunit modulation of the GABABZ receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in animal models. Eszopiclone binds selectively to the brain alpha subunit of the GABA A omega-1 receptor. The mechanism of action of Eszopiclone is not completely understood. It is thought that Eszopiclone acts on the benzodiazepine receptors as an agonist and interacts with GABA-receptor complexes. Used for the treatment of insomnia.

Pregabalin, marketed under the brand name Lyrica among others. LYRICA is indicated for: Neuropathic pain associated with diabetic peripheral neuropathy (DPN) Postherpetic neuralgia (PHN); Adjunctive therapy for adult patients with partial onset seizures; Fibromyalgia; Neuropathic pain associated with spinal cord injury. It has been shown the clinical effects of pregabalin are likely due to direct and selective interactions with α(2)δ-1 and α(2)δ-2 subunits of voltage-gated calcium channels. While pregabalin is a structural derivative of the inhibitory neurotransmitter gamma aminobutyric acid (GABA), it does not bind directly to GABAA, GABAB, or benzodiazepine receptors, does not augment GABAA responses in cultured neurons, does not alter rat brain GABA concentration or have acute effects on GABA uptake or degradation. However, in cultured neurons prolonged application of pregabalin increases the density of GABA transporter protein and increases the rate of functional GABA transport. Pregabalin does not block sodium channels, is not active at opiate receptors, and does not alter cyclooxygenase enzyme activity. It is inactive at serotonin and dopamine receptors and does not inhibit dopamine, serotonin, or noradrenaline reuptake.

NAMENDA (marketed under the brands Namenda among others) is an N-methyl-D-aspartate (NMDA) receptor antagonist indicated for the treatment of moderate to severe dementia of the Alzheimer’s type. Persistent activation of central nervous system N-methyl-D-aspartate (NMDA) receptors by the excitatory amino acid glutamate has been hypothesized to contribute to the symptomatology of Alzheimer’s disease. Memantine is postulated to exert its therapeutic effect through its action as a low to moderate affinity uncompetitive (open-channel) NMDA receptor antagonist which binds preferentially to the NMDA receptor-operated cation channels. There is no evidence that memantine prevents or slows neurodegeneration in patients with Alzheimer’s disease. Memantine showed low to negligible affinity for GABA, benzodiazepine, dopamine, adrenergic, histamine and glycine receptors and for voltage-dependent Ca2+, Na+ or K+ channels. Memantine also showed antagonistic effects at the 5HT3 receptor with a potency similar to that for the NMDA receptor and blocked nicotinic acetylcholine receptors with one-sixth to one-tenth the potency. In vitro studies have shown that memantine does not affect the reversible inhibition of acetylcholinesterase by donepezil, galantamine, or tacrine.

Atomoxetine is indicated for the treatment of Attention-Deficit/Hyperactivity Disorder. The precise mechanism by which atomoxetine produces its therapeutic effects in Attention-Deficit/Hyperactivity Disorder (ADHD) is unknown, but is thought to be related to selective inhibition of the pre-synaptic norepinephrine transporter. Most common adverse reactions are: nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence, constipation, dry mouth, dizziness, erectile dysfunction, and urinary hesitation. Atomoxetine is a substrate for CYP2D6 and hence concurrent treatment with CYP2D6 inhibitors such as bupropion (Wellbutrin) or fluoxetine (Prozac) is not recommended, as this can lead to significant elevations of plasma atomoxetine levels.

Aripiprazole is the first next-generation atypical antipsychotic. The unique actions of aripiprazole in humans are likely a combination of "functionally selective" activation of D(2) (and possibly D(3))-dopamine receptors and serotonin 5-HT(1A) receptors, coupled with inhibition of 5-HT(2A) receptors. Aripiprazole was approved by FDA (Abilify trade name) for the treatment of schizophrenia; manic and mixed episodes associated with bipolar I disorder; major depressive disorder; irritability associated with autistic disorder; Tourette’s disorder and agitation associated with schizophrenia or bipolar mania.

Eletriptan (eletriptan hydrobromide, trade name Relpax) is a selective 5-hydroxytryptamine (5-HT1B/1D) serotonin receptor agonist (triptan) indicated for the acute treatment of migraine with or without aura in adults. Eletriptan binds with high affinity to 5-HT1B, 5-HT1D and 5-HT1F receptors, and has modest affinity for 5-HT1A, 5-HT1E, 5-HT2B and 5-HT7 receptors. The therapeutic activity of eletriptan for the treatment of migraine headache is thought to be due to the agonist effects at the 5-HT1B/1D receptors on intracranial blood vessels (including the arterio-venous anastomoses) and sensory nerves of the trigeminal system which result in cranial vessel constriction and inhibition of pro-inflammatory neuropeptide release. Eletriptan (Relpax) has been approved for use in the acute treatment of migraine in 51 countries and has been introduced in 17 countries including Mexico, Italy, France and Japan.

Escitalopram is one of a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). Escitalopram, also known by the brand names Lexapro and Cipralex among others, is an antidepressant. The mechanism of antidepressant action of escitalopram, the S-enantiomer of racemic citalopram, is presumed to be linked to potentiation of serotonergic activity in the central nervous system (CNS) resulting from its inhibition of CNS neuronal reuptake of serotonin (5-HT). In vitro and in vivo studies in animals suggest that escitalopram is a highly selective serotonin reuptake inhibitor (SSRI) with minimal effects on norepinephrine and dopamine neuronal reuptake. Escitalopram is at least 100-fold more potent than the R-enantiomer with respect to inhibition of 5-HT reuptake and inhibition of 5-HT neuronal firing rate. LEXAPRO (escitalopram) is indicated for the treatment of major depressive disorder and generalized anxiety disorder .

Ziprasidone is atypical antipsychotic, approved by the U.S. Food and Drug Administration for the treatment of schizophrenia, and acute mania and mixed states associated with bipolar disorder. Intramuscilar injections of Ziprasidone are indicated for rapid control of the agitation in schizophrenic patients. Ziprasidone is used off-label for treatment of major depressive disorder, anxiety, obsessive compulsive disorder, borderline personality disorder. Ziprasidone functions as an antagonist at the D2, 5HT2A, and 5HT1D receptors, and as an agonist at the 5HT1A receptor.

Galantamine (RAZADYNE®, galantamine hydrobromide) is a benzazepine derived from norbelladine. It is found in Galanthus and other Amaryllidaceae. It is a reversible, competitive acetylcholinesterase inhibitor that is used for the treatment of mild to moderate dementia of the Alzheimer’s type. Although the etiology of cognitive impairment in Alzheimer’s disease is not fully understood, it has been reported that acetylcholine-producing neurons degenerate in the brains of patients with Alzheimer’s disease. The degree of this cholinergic loss has been correlated with degree of cognitive impairment and density of amyloid plaques (a neuropathological hallmark of Alzheimer’s disease). While the precise mechanism of galantamine’s (RAZADYNE®, galantamine hydrobromide) action is unknown, it is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by acetylcholinesterase. If this mechanism is correct, galantamine’s (RAZADYNE®, galantamine hydrobromide) effect may lessen as the disease process advances and fewer cholinergic neurons remain functionally intact. There is no evidence that galantamine (RAZADYNE®, galantamine hydrobromide) alters the course of the underlying dementing process.

Frovatriptan succinate (trade name Frova) is a selective 5-hydroxytryptamine1 (5-HT1B/1D) receptor subtype agonist, and is used for the treatment of migraine attacks with or without aura in adults. Frovatriptan has no significant effects on GABAA mediated channel activity and has no significant affinity for benzodiazepine binding sites. Frovatriptan is believed to act on extracerebral, intracranial arteries and to inhibit excessive dilation of these vessels in migraine. Serious but rare cardiac events have been reported in patients with risk factors predictive of coronary artery disease (CAD). These include coronary artery vasospasm, transient myocardial ischemia, myocardial infarction, ventricular tachycardia and ventricular fibrillation.