The N-methyl-D-aspartatereceptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA and kainate receptors. Depending on its subunit composition, its ligands are glutamate and glycine (or D-serine). However, the binding of the ligands is typically not sufficient to open the channel as it may be blocked by Mg2+ ions which are only removed when the neuron is sufficiently depolarized. Thus, the channel acts as a “coincidence detector” and only once both of these conditions are met, the channel opens and it allows positively charged ions (cations) to flow through the cell membrane. The NMDA receptor is thought to be very important for controlling synaptic plasticity and mediating learning and memory functions.
Ampakines or AMPAkines are a subgroup of AMPA receptor positive allosteric modulators with a benzamide or closely related chemical structure. They are also known as "CX compounds". Ampakines take their name from the AMPA receptor (AMPAR), a type of ionotropic glutamate receptor with which the ampakines interact and act as positive allosteric modulators (PAMs) of. Although all ampakines are AMPAR PAMs, not all AMPAR PAMs are ampakines.
Methylnaltrexone, used in form of methylnaltrexone bromide, is a medication that acts as a peripherally acting μ-opioid receptor antagonist that acts to reverse some of the side effects of opioid drugs such as constipation without significantly affecting pain relief or precipitating withdrawals. Because MNTX is a quaternary ammonium cation, it cannot cross the blood–brain barrier, and so has antagonist effects throughout the body, counteracting effects such as itching and constipation, but without affecting opioid effects in the brain such as pain relief. However, since a significant fraction of opioid analgesia can be mediated by opioid receptors on peripheral sensory neurons, particularly in inflammatory conditions such as arthritis, traumatic or surgical pain, MNTX may increase pain under such circumstances.
LY-503430 is an AMPA receptor positive allosteric modulator developed by Eli Lilly.
Cyclothiazide, sometimes abbreviated CTZ, is a benzothiadiazide (thiazide) diuretic and antihypertensive that was originally introduced in the United States in 1963 by Eli Lilly and was subsequently also marketed in Europe and Japan. Related drugs include diazoxide, hydrochlorothiazide, and chlorothiazide.
LY-404187 is an AMPA receptor positive allosteric modulator which was developed by Eli Lilly and Company. It is a member of the biarylpropylsulfonamide class of AMPA receptor potentiators.
Eliprodil is an NMDA antagonist drug candidate which selectively inhibits the NR2B (GLUN2B) subtype NMDA receptor at submicromolar concentrations. Eliprodil failed a Phase III clinical trial for the treatment of acute ischemic stroke in 1996, sponsored by Synthélabo Recherche.
Afatinib, sold under the brand name Gilotrif among others, is a medication which is used to treat non-small cell lung carcinoma (NSCLC). It belongs to the tyrosine kinase inhibitor family of medications. It is taken by mouth.
Perampanel, sold under the brand name Fycompa, is an anti-epileptic medication developed by Eisai Co. that is used in addition to other drugs to treat partial seizures and generalized tonic-clonic seizures for people older than twelve years. It was first approved in 2012, and as of 2016, its optimal role in the treatment of epilepsy relative to other drugs was not clear. It was the first antiepileptic drug in the class of selective non-competitive antagonist of AMPA receptors.
Talampanel is a drug which has been investigated for the treatment of epilepsy, malignant gliomas, and amyotrophic lateral sclerosis (ALS).
Repinotan (BAYx3702), an aminomethylchroman derivative, is a selective 5-HT1A receptor full agonist with high potency and efficacy. It has neuroprotective effects in animal studies, and was trialed in humans for reducing brain injury following head trauma. It was subsequently trialed up to phase II for treatment of stroke, but while side effects were mild and consisted mainly of nausea, repinotan failed to demonstrate sufficient efficacy to justify further clinical trials. However, repinotan continues to be investigated for other applications, and was found to be effective at counteracting the respiratory depression produced by morphine, though with slight reduction in analgesic effects.
Traxoprodil is a drug developed by Pfizer which acts as an NMDA antagonist, selective for the NR2B subunit. It has neuroprotective, analgesic, and anti-Parkinsonian effects in animal studies. Traxoprodil has been researched in humans as a potential treatment to lessen the damage to the brain after stroke, but results from clinical trials showed only modest benefit. The drug was found to cause EKG abnormalities and its clinical development was stopped. More recent animal studies have suggested traxoprodil may exhibit rapid-acting antidepressant effects similar to those of ketamine, although there is some evidence for similar psychoactive side effects and abuse potential at higher doses, which might limit clinical acceptance of traxoprodil for this application.
Nintedanib, sold under the brand names Ofev and Vargatef, is an oral medication used for the treatment of idiopathic pulmonary fibrosis and along with other medications for some types of non-small-cell lung cancer.
An orexin receptor antagonist, or orexin antagonist, is a drug that inhibits the effect of orexin by acting as a receptor antagonist of one (selective orexin receptor antagonist or SORA) or both (dual orexin receptor antagonis or DORA) of the orexin receptors, OX1 and OX2. Medical applications include treatment of sleep disorders such as insomnia.
Becampanel (INN) (code name AMP397) is a quinoxalinedione derivative drug which acts as a competitive antagonist of the AMPA receptor (IC50 = 11 nM). It was investigated as an anticonvulsant for the treatment of epilepsy by Novartis, and was also looked at as a potential treatment for neuropathic pain and cerebral ischemia, but never completed clinical trials.
Selurampanel is a drug closely related to the quinoxalinedione series which acts as a competitive antagonist of the AMPA and kainate receptors and, as of 2015, is being investigated in clinical trials by Novartis for the treatment of epilepsy. It has also been studied in the acute treatment of migraine, and was found to produce some pain relief, but with a relatively high rate of side effects.
Fanapanel, also known as MPQX, is a quinoxalinedione derivative drug which acts as a competitive antagonist of the AMPA receptor. It was under development by Schering AG for the treatment of cerebral ischemia associated with stroke and trauma, but clinical trials were halted for safety reasons related to possible glial cell toxicity and due to intolerable side effects such as excessive sedation, reduction in consciousness, and transient neurological deterioration. The drug was also observed to produce visual alteration and impairment, including blurred vision, strongly impaired color perception, and reduced visual acuity and dark vision, side effects thought to be caused by blockade of AMPA receptors in the retina.
Afoxolaner (INN) is an insecticide and acaricide that belongs to the isoxazoline chemical compound group.
Willardiine (correctly spelled with two successive i's) or (S)-1-(2-amino-2-carboxyethyl)pyrimidine-2,4-dione is a chemical compound that occurs naturally in the seeds of Mariosousa willardiana and Acacia sensu lato. The seedlings of these plants contain enzymes capable of complex chemical substitutions that result in the formation of free amino acids (See: #Synthesis). Willardiine is frequently studied for its function in higher level plants. Additionally, many derivates of willardiine are researched for their potential in pharmaceutical development. Willardiine was first discovered in 1959 by R. Gmelin, when he isolated several free, non-protein amino acids from Acacia willardiana (another name for Mariosousa willardiana) when he was studying how these families of plants synthesize uracilyalanines. A related compound, Isowillardiine, was concurrently isolated by a different group, and it was discovered that the two compounds had different structural and functional properties. Subsequent research on willardiine has focused on the functional significance of different substitutions at the nitrogen group and the development of analogs of willardiine with different pharmacokinetic properties. In general, Willardiine is the one of the first compounds studied in which slight changes to molecular structure result in compounds with significantly different pharmacokinetic properties.
