Cloperastine (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

) or cloperastin, in the forms of cloperastine hydrochloride ( JAN) (brand names Hustazol, Nitossil, Seki) and cloperastine fendizoate (or hybenzoate), 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 ...

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 provid ...

that is marketed as a cough suppressant in Japan,

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China (abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delta i ...

, and in some

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

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

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

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 interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targ ...

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 ( 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 elec ...

of the σ₁ receptor (K_i = 20 nM) (likely an agonist), 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 neurotransmitter called acetylcholine (ACh) at synapses in the central and peripheral nervous system. These agents inhibit the parasympathetic nervous sys ...

. It is thought that the latter two properties contribute to

side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s, such as sedation 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 asleep ...

, 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 tetrachloromethane, also recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound with the chemica ...

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

Antitussives Chlorobenzenes Ethers H1 receptor antagonists Muscarinic antagonists 1-Piperidinyl compounds Potassium channel blockers Sigma receptor ligands {{respiratory-system-drug-stub

Side effects

Pharmacology

Synthesis

See also

References