Remacemide is a

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

which acts as a low-affinity

NMDA antagonist NMDA receptor antagonists are a class of drugs that work to antagonize, or inhibit the action of, the ''N''-Methyl-D-aspartate receptor ( NMDAR). They are commonly used as anesthetics for humans and animals; the state of anesthesia they ind ...

with

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

channel blocking properties. It has been studied for the treatment of acute

ischemic stroke Stroke is a medical condition in which poor blood flow to a part of the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop ...

epilepsy Epilepsy is a group of Non-communicable disease, non-communicable Neurological disorder, neurological disorders characterized by a tendency for recurrent, unprovoked Seizure, seizures. A seizure is a sudden burst of abnormal electrical activit ...

Huntington's disease Huntington's disease (HD), also known as Huntington's chorea, is an incurable neurodegenerative disease that is mostly Genetic disorder#Autosomal dominant, inherited. It typically presents as a triad of progressive psychiatric, cognitive, and ...

, and

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...

. Because remacemide has only a modest effect on seizure frequency and causes

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a ...

, it is no longer believed that remacemide will be an effective treatment for epilepsy. Although no such statement has been made about remacemide's potential for treating stroke, Huntington's, or Parkinson's, remacemide is no longer being developed for these conditions. Remacemide is also known as remacemide hydrochloride, (±)-2-amino-''N''-(1-methyl-1,2-diphenylethyl)-acetamide hydrochloride, or FPL 12924AA.

Adverse effects

*dizziness *nausea

Lack of adverse effects

Unlike many other treatments for epilepsy, remacemide does not appear to impair cognitive performance or driving performance in humans, although the evidence for effects on cognitive performance in animals has been mixed. Remacemide is not a sedative.

Toxicity

The median toxic dose of remacemide for neural impairment tests in mice is 5.6 mg/kg. Its estimated

median lethal dose In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a given substance. The value of LD50 for a substance is the dose re ...

is about 927.3 mg/kg in mice. It has a favorable

therapeutic index The therapeutic index (TI; also referred to as therapeutic ratio) is a quantitative measurement of the relative safety of a drug with regard to risk of overdose. It is a comparison of the amount of a therapeutic agent that causes toxicity to the ...

of 28.1 in mice.

Drug interactions

Levodopa

Remacemide delays the absorption of

levodopa Levodopa, also known as L-DOPA and sold under many brand names, is a dopaminergic medication which is used in the treatment of Parkinson's disease (PD) and certain other conditions like dopamine-responsive dystonia and restless legs syndrome. ...

(300 mg of remacemide one hour before levodopa treatment delays mean time to peak levodopa plasma concentration by 20%) but not its total absorption (area-under-the-curve for levodopa plasma concentration was unchanged).

Sodium valproate

Remacemide does not interact with sodium valproate, a treatment for epilepsy.

Carbamazepine

Ramacemide does interact with

carbamazepine Carbamazepine, sold under the brand name Tegretol among others, is an anticonvulsant medication used in the treatment of epilepsy and neuropathic pain. It is used as an adjunctive treatment in schizophrenia along with other medications and as ...

. Remacemide inhibits the metabolism of carbamazepine, while carbamazepine induces the metabolism of remacemide and FPL 12495.

Alcohol

Combined consumption with alcohol can increase reaction time and lower alertness, while also hindering memory formation, which are typical side effects of alcohol.

Remacemide salts

Remacemide is most commonly synthesized as the

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

remacemide hydrochloride. However, there has been some investigation into other remacemide salts and their

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

s, as different remacemide salts might taste more pleasant or have a

solubility In chemistry, solubility is the ability of a chemical substance, substance, the solute, to form a solution (chemistry), solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form su ...

more suitable for a pediatric suspension

formulation Formulation is a term used in various senses in various applications, both the material and the abstract or formal. Its fundamental meaning is the putting together of components in appropriate relationships or structures, according to a formula ...

Mechanism of action

Remacemide binds weakly and noncompetitively to the ionic channel site of the NMDA receptor complex. Remacemide binds both allosterically and in the channel. However, because remacemide binds so weakly to NMDAR, much of remacemide's ''in vivo'' effect against

excitotoxicity In excitotoxicity, neuron, nerve cells suffer damage or death when the levels of otherwise necessary and safe neurotransmitters such as glutamic acid, glutamate become pathologically high, resulting in excessive stimulation of cell surface recept ...

is thought to be caused by its metabolic transformation to the more potent desglycine derivative FPL 12495. That is, remacemide may actually act as a

prodrug A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be ...

to deliver the active

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

FPL 12495 to the central nervous system.

Epilepsy

In a well validated and described genetic model of absence epilepsy, rats of the WAG/Rij strain, remacemide and its metabolite FPL 12495 were found to have a common for glutamate antagonist usual effect on the number of spike/wave discharges

EEG Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The bio signals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neoc ...

, the drugs decrease spike/wave discharges dose dependently. However, in contrast to most other glutamate antagonists, FPL 12495 increased the duration of the spike-wave discharges.

Pharmacokinetics

Blood–brain barrier

The brain uptake index (BUI), a measure of a drug's ability to pass the

blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...

that involves the injection of radiolabeled test and reference substances into the

common carotid artery In anatomy, the left and right common carotid arteries (carotids) () are artery, arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external carotid artery, external and internal carotid artery, inte ...

of anesthetized animals, for remacemide is 51 ± 0.9 SD.

Enantiomers

The (-)

stereoisomer In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...

of remacemide is of equal potency to the racemic mixture in preventing maximal electroshock seizures when administered orally to rats, while the (+)stereoisomer is less potent.

Metabolites

FPL 12495

Much of remacemide's effect ''in vivo'' is thought to be caused by the desglycine derivative FPL 12495 (±). FPL 12495 (±) binds specifically and non-competitively to NMDAR. Its effect on maximal electroconvulsive shock is more potent than remacemide. The S isomer (FPL 12859) is even more potent than the

racemic mixture In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...

, while the R isomer is less potent than the racemate. FPL 12495 is sometimes referred to as ARL 12495AA.

Other metabolites

FPL 15053

FPL 15053 is the ''N''- of remacemide, and exhibits modest binding to NMDAR and modest effects on convulsions and mortality in test mice and rats.

FPL 14331 and FPL 14465

FPL 14331 and FPL 14465 are the ''p''- of remacemide, and they exhibit some efficacy against maximal electroconvulsive shock after i.p. and i.v. dosing.

FPL 15455

FPL 15455 is an oxoacetate metabolite of remacemide, but has no demonstrated biological activity.

FPL 14991 and FPL 14981

FPL 14991 and FPL 14981 are both ''β''- of remacemide, and they display modest efficacy against maximal electroconvulsive shock in mice. However FPL 14981 and not FPL 14991 prevents NMDLA-induced convulsions and mortality in mice.

FPL 13592 and FPL 15112

The hydroxy-methyl derivative of remacemide (FPL 13592) and its (FPL 15112) prevents electric shock-induced convulsions only after i.v. administration; only the desglycine derivative binds to NMDAR.

FPL 14467

FPL 14467 (''p''-) is inactive ''in vivo'' and weak in binding NMDAR.

Pharmacodynamics

The values for 50% displacement of were 68 μM for remacemide and 0.48 μM for FPL 12495AA.

History

Current status

Remacemide is an

experimental drug An experimental drug is a medicinal product (a drug or vaccine) that has not yet received drug approval, approval from governmental regulatory agency, regulatory authorities for routine use in human medicine, human or veterinary medicine. A medicin ...

most recently being developed by the British multinational

pharmaceutical company The pharmaceutical industry is a Medicine, medical industry that discovers, develops, produces, and markets pharmaceutical goods such as medications and medical devices. Medications are then administered to (or Self-medicate, self-administered b ...

AstraZeneca AstraZeneca plc () (AZ) is a British-Swedish multinational pharmaceutical and biotechnology company with its headquarters at the Cambridge Biomedical Campus in Cambridge, UK. It has a portfolio of products for major diseases in areas includi ...

. However, there has been little news of its progress since 2000. A few sources indicate that its development has been discontinued.

Changing hands

Remacemide was one of the last drugs under development by the now-defunct English pharmaceutical company

Fisons Fisons plc was a British Multinational corporation, multinational pharmaceutical, scientific instruments and horticultural chemicals company headquartered in Ipswich, United Kingdom. It was listed on the London Stock Exchange and was once a cons ...

. In 1995, it was acquired along with most of Fisons'

research and development Research and development (R&D or R+D), known in some countries as OKB, experiment and design, is the set of innovative activities undertaken by corporations or governments in developing new services or products. R&D constitutes the first stage ...

operations by the Swedish pharmaceutical company Astra, which in 1999 merged with the British company

Zeneca Zeneca (officially Zeneca Group PLC) was a British multinational pharmaceutical company headquartered in London, United Kingdom. It was formed in June 1993 by the demerger of the pharmaceuticals and agrochemicals businesses of Imperial Chemi ...

to form

. In 2000, AstraZeneca considered possibly licensing out remacemide to some other pharmaceutical company, but there has been little news about remacemide since then. Remacemide's development may have been discontinued in July 2001.

Discovery and development under Fisons

In 1990, researchers at Fisons found that remacemide acted as an

anticonvulsant Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatme ...

in mice and rats . Because of remacemide's potential as a neuroprotective agent through preventing glutamate toxicity, it was soon also under investigation as a treatment for

and

Astra

By 1995, when Astra acquired remacemide, it was already in Phase IIb clinical development as an anti-epileptic drug and Phase I clinical development as a treatment for Huntington's .

AstraZeneca

By 1998, when Astra announced its merger with

, remacemide had progressed to Phase III trials for epilepsy and Phase II trials for Parkinson's disease, and Astra was also investigating its potential for treating

neuropathic pain Neuropathic pain is pain caused by a lesion or disease of the somatosensory nervous system. Neuropathic pain may be associated with abnormal sensations called dysesthesia or pain from normally non-painful stimuli (allodynia). It may have continuo ...

In 1999, after the merger, AstraZeneca reported that they were investigating remacemide for its neuroprotective effects, and that they planned regulatory submissions for

in 2001 and for

and

in 2003. Remacemide, under the trade name Ecovia, was designated an

orphan drug An orphan drug is a medication, pharmaceutical agent that is developed to treat certain rare medical conditions. An orphan drug would not be profitable to produce without government assistance, due to the small population of patients affected by th ...

for the treatment of

by the

FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

in March 2000. Remacemide was last mentioned in

's reports on its R&D pipeline in 2000, when it was in Phase III

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

s for remacemide in the treatment of

and Phase II for treatment of

. At that time, the submission of the New Drug Application (NDA) to the

and the Marketing Authorization Application to the CHMP was projected for Huntington's in 2001 and for Parkinson's after 2003, but there has been no news of such submission. In this report, it was also noted that remacemide was "under strategic review and a potential candidate for licensing activity" (see thi
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about drug

licensing A license (American English) or licence ( Commonwealth English) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another par ...

Current news

There are no clinical trials of remacemide in progress, according to the Huntington Study Group, and the Parkinson Study Group.

Availability