Cloperastine ( INN) or cloperastin, in the forms of cloperastine hydrochloride ( JAN) (brand names Hustazol, Nitossil, Seki) and cloperastine fendizoate, is an

antitussive Cold medicines are a group of medications taken individually or in combination as a treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The term encompasses a broad array of drugs, including ana ...

and

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

that is marketed as a

cough suppressant Cold medicines are a group of medicinal, medications taken individually or in Combination drug, combination as a Symptomatic treatment, treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The ter ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Hong Kong Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

and in some

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

an countries. It was first introduced in 1972 in Japan, and then in

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

in 1981.

Side effects

Adverse effects may include sedation, drowsiness, heartburn, and thickening of bronchial secretions.

Pharmacology

The precise

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...

of cloperastine is not fully clear, but several different biological activities have been identified for the drug, of which include:

ligand In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...

of the σ₁ receptor (K_i = 20 nM) (likely an

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

), GIRK channel blocker (described as "potent"),

(K_i = 3.8 nM for the H₁ receptor), and

anticholinergic Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central nervous system, central and peripheral nervous system. These agents inhibit the parasympatheti ...

. It is thought that the latter two properties contribute to

side effect In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually use ...

s, such as

sedation Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, ...

and

somnolence Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling aslee ...

, while the former two may be involved in or responsible for the antitussive efficacy of cloperastine.

Synthesis

The halogenation of 4-Chlorobenzhydrol 19-56-2(1) with

phosphorus tribromide Phosphorus tribromide is a colourless liquid with the formula P Br3. The liquid fumes in moist air due to hydrolysis and has a penetrating odour. It is used in the laboratory for the conversion of alcohols to alkyl bromides. Preparation PBr3 ...

tetrachloromethane Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a n ...

gives 1-(Bromophenylmethyl)-4-chlorobenzene 48-54-9(2). Treatment with ethylenechlorohydrin (

2-Chloroethanol 2-Chloroethanol (also called ethylene chlorohydrin or glycol chlorohydrin) is an organic chemical compound with the chemical formula HOCH2CH2Cl and the ''simplest'' beta-halohydrin (chlorohydrin). This colorless liquid has a pleasant ether-like od ...

) 07-07-3(3) gives 1-(4-Chlorobenzhydryl)oxy-2-chloroethane 321-46-0(4). Reaction with

piperidine Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic amine consists of a six-membered ring containing five methylene bridges (–CH2–) and one amine bridge (–NH–). It is a colorless liquid with an odor de ...

(5) completes the synthesis of ''Cloperastine'' (6).

References

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Pharmacodynamics Pharmacodynamics (PD) is the study of the biochemistry, biochemical and physiology, physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or comb ...

, titlestyle = background:#ccccff , list1 = {{Histamine receptor modulators {{Ion channel modulators {{Muscarinic acetylcholine receptor modulators {{Sigma receptor modulators 1-Piperidinyl compounds 4-Chlorophenyl compounds Antitussives Ethanolamines Ethers H1 receptor antagonists M1 receptor antagonists M2 receptor antagonists M3 receptor antagonists M4 receptor antagonists M5 receptor antagonists Potassium channel blockers Sigma receptor modulators

Side effects

Pharmacology

Synthesis

See also

References