Gefapixant

{{Short description|Chemical compound}}

{{Use American English|date=October 2023}}

{{Use dmy dates|date=October 2023}}

{{cs1 config |name-list-style=vanc |display-authors=6}}

{{Drugbox

| image = Gefapixant structure.svg

| tradename = Lyfnua

| ATC_prefix = R05

| ATC_suffix = DB29

| legal_US =

| legal_EU = Rx-only

| legal_EU_comment = {{cite web | title=Lyfnua EPAR | website=European Medicines Agency | date=29 September 2023 | url=https://www.ema.europa.eu/en/medicines/human/EPAR/lyfnua | access-date=5 October 2023}}

| legal_status =

| bioavailability =

| metabolism =

| elimination_half-life =

| excretion =

| CAS_number = 1015787-98-0

| PubChem = 24764487

| UNII = 6K6L7E3F1L

| ChemSpiderID = 58828660

| DrugBank = DB15097

| KEGG = D11349

| ChEMBL = 3716057

| synonyms = MK-7264

| IUPAC_name = 5-(2,4-diaminopyrimidin-5-yl)oxy-2-methoxy-4-propan-2-ylbenzenesulfonamide

| C=14 | H=19 | N=5 | O=4 | S=1

| SMILES = CC(C)C1=CC(=C(C=C1OC2=CN=C(N=C2N)N)S(=O)(=O)N)OC

| StdInChI=1S/C14H19N5O4S/c1-7(2)8-4-10(22-3)12(24(17,20)21)5-9(8)23-11-6-18-14(16)19-13(11)15/h4-7H,1-3H3,(H2,17,20,21)(H4,15,16,18,19)

| StdInChIKey = HLWURFKMDLAKOD-UHFFFAOYSA-N

}}

Gefapixant, sold under the brand name Lyfnua, is a medication used to treat chronic (long-term) cough. It acts as an antagonist of the P2RX3 receptor.{{cite journal | vauthors = Muccino D, Green S | title = Update on the clinical development of gefapixant, a P2X3 receptor antagonist for the treatment of refractory chronic cough | journal = Pulmonary Pharmacology & Therapeutics | volume = 56 | pages = 75–78 | date = June 2019 | pmid = 30880151 | doi = 10.1016/j.pupt.2019.03.006 | s2cid = 81982653 | doi-access = free }}{{cite journal | vauthors = Richards D, Gever JR, Ford AP, Fountain SJ | title = Action of MK-7264 (gefapixant) at human P2X3 and P2X2/3 receptors and in vivo efficacy in models of sensitisation | journal = British Journal of Pharmacology | volume = 176 | issue = 13 | pages = 2279–2291 | date = July 2019 | pmid = 30927255 | doi = 10.1111/bph.14677 | pmc = 6555852 }}{{cite journal | vauthors = Marucci G, Dal Ben D, Buccioni M, Martí Navia A, Spinaci A, Volpini R, Lambertucci C | title = Update on novel purinergic P2X3 and P2X2/3 receptor antagonists and their potential therapeutic applications | journal = Expert Opinion on Therapeutic Patents | volume = 29 | issue = 12 | pages = 943–963 | date = December 2019 | pmid = 31726893 | doi = 10.1080/13543776.2019.1693542 | s2cid = 208037373 | hdl = 11581/435751 | hdl-access = free }}

It was authorized for medical use in the European Union in September 2023.