Ciproxifan is an extremely potent

histamine Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in ...

H₃

inverse agonist In pharmacology, an inverse agonist is a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. A neutral antagonist has no activity in the absence of an agonist or inverse agon ...

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, riv ...

. The histamine H₃ receptor is an inhibitory autoreceptor located on histaminergic nerve terminals, and is believed to be involved in modulating the release of histamine in the brain. Histamine has an excitatory effect in the brain via H₁ receptors in the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...

, and so drugs such as ciproxifan which block the H₃ receptor and consequently allow more histamine to be released have an alertness-promoting effect. Ciproxifan produces wakefulness and attentiveness in animal studies, and produced cognitive enhancing effects without prominent stimulant effects at relatively low levels of receptor occupancy, and pronounced wakefulness at higher doses. It has therefore been proposed as a potential treatment for sleep disorders such as

narcolepsy Narcolepsy is a long-term neurological disorder that involves a decreased ability to regulate sleep–wake cycles. Symptoms often include periods of excessive daytime sleepiness and brief involuntary sleep episodes. About 70% of those affec ...

and to improve

vigilance Vigilance may refer to: * Alertness * Vigilance, a creature ability in the ''Magic: The Gathering'' collectible card game * ''Vigilance'' (album), by Threat Signal * Vigilance (behavioural ecology), the watchfulness of prey for nearby predator ...

in old age, particularly in the treatment of conditions such as

Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

. It also potentiated the effects of antipsychotic drugs, and has been suggested as an adjuvant treatment for schizophrenia.

References

Nootropics H3 receptor antagonists Imidazoles Piceol ethers Cyclopropanes {{nervous-system-drug-stub