Israpafant (Y-24180) is a drug which acts as a selective antagonist for the platelet-activating factor receptor, and was originally developed for the treatment of

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

. Its chemical structure is a

thienotriazolodiazepine A thienotriazolodiazepine is a heterocyclic compound containing a diazepine ring fused to thiophene and triazole rings. Thienotriazolodiazepine forms the central core of several pharmaceutical drugs including: * Brotizolam * Ciclotizolam * De ...

, closely related to the sedative

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...

derivative

etizolam Etizolam (marketed under many brand names) is a thienodiazepine derivative which is a benzodiazepine analog. The etizolam molecule differs from a benzodiazepine in that the benzene ring has been replaced by a thiophene ring and triazole ring ha ...

. However israpafant binds far more tightly to the platelet-activating factor receptor, with an IC₅₀ of 0.84nM for inhibiting PAF-induced human platelet aggregation (compared to etizolam's IC₅₀ of 998nM at this target), while it binds only weakly to benzodiazepine receptors, with a Ki of 3680nM. Israpafant has been found to inhibit the activation of

eosinophil Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells (WBCs) and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. A ...

cells, and consequently delays the development of immune responses. It has also been shown to have anti-

nephrotoxic Nephrotoxicity is toxicity in the kidneys. It is a poisonous effect of some substances, both toxic chemicals and medications, on kidney function. There are various forms, and some drugs may affect kidney function in more than one way. Nephrotoxins ...

properties, and to mobilize calcium transport.

References

Thienotriazolodiazepines {{drug-stub

See also

References