Niaprazine ( INN) (brand name Nopron) is a

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but ...

hypnotic Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia ...

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhala ...

of the

phenylpiperazine 1-Phenylpiperazine is a simple chemical compound featuring a phenyl group bound to a piperazine ring. The suffix ‘-piprazole’ is sometimes used in the names of drugs to indicate they belong to this class. List phenylpiperazine derivativesAlp ...

group. It has been used in the treatment of

sleep disturbance A sleep disorder, or somnipathy, is a medical disorder of an individual's sleep patterns. Some sleep disorders are severe enough to interfere with normal physical, mental, social and emotional functioning. Polysomnography and actigraphy are tests ...

s since the early 1970s in several

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 Continent#Subcontinents, subcontinent of Eurasia ...

an countries including

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

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 ...

, and

Luxembourg Luxembourg ( ; lb, Lëtzebuerg ; french: link=no, Luxembourg; german: link=no, Luxemburg), officially the Grand Duchy of Luxembourg, ; french: link=no, Grand-Duché de Luxembourg ; german: link=no, Großherzogtum Luxemburg is a small lan ...

. It is commonly used with children and adolescents on account of its favorable

safety Safety is the state of being "safe", the condition of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk. Meanings There are two slightly di ...

and tolerability profile and lack of abuse potential. Originally believed to act as an

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 provide ...

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 ...

, niaprazine was later discovered to have low or no binding affinity for the H₁ and mACh receptors (K_i = > 1 μM), and was instead found to act as a potent and selective 5-HT_2A and α₁-adrenergic receptor

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, ri ...

(K_i = 75 nM and 86 nM, respectively). It possesses low or no affinity for the 5-HT_1A, 5-HT_2B, D₂, and

β-adrenergic The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like bet ...

, as well as at SERT and VMAT (K_i = all > 1 μM), but it does have some affinity for the α₂-adrenergic receptor (K_i = 730 nM). Niaprazine has been shown to metabolize to the compound ''para''-fluorophenylpiperazine (''p''FPP) in a similar manner to how

trazodone Trazodone, sold under many brand names, is an antidepressant medication. It is used to treat major depressive disorder, anxiety disorders, and difficulties with sleep. The medication is taken orally. Common side-effects include dry mouth, f ...

and

nefazodone Nefazodone, sold formerly under the brand names Serzone, Dutonin, and Nefadar among others, is an atypical antidepressant which was first marketed by Bristol-Myers Squibb (BMS) in 1994 but has since largely been discontinued. BMS withdrew it from ...

metabolize to ''meta''-chlorophenylpiperazine (''m''CPP). It is unclear what role, if any, ''p''FPP plays in the clinical effects of niaprazine. However, from animal studies it is known that ''p''FPP, unlike niaprazine, does not produce sedative effects, and instead exerts a behavioral profile indicative of

serotonergic Serotonergic () or serotoninergic () means "pertaining to or affecting serotonin". Serotonin is a neurotransmitter. A synapse is serotonergic if it uses serotonin as its neurotransmitter. A serotonergic neuron ''produces'' serotonin. A substance is ...

activation.

References

{{Piperazines Alpha-1 blockers Alpha-2 blockers Fluoroarenes Hypnotics Nicotinamides Phenylpiperazines Sedatives