{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T01:10:21Z","timestamp":1788311421057,"version":"build-2803163510"},"reference-count":33,"publisher":"American Veterinary Medical Association (AVMA)","issue":"3","license":[{"start":{"date-parts":[[2024,3,1]],"date-time":"2024-03-01T00:00:00Z","timestamp":1709251200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ajvr"],"published-print":{"date-parts":[[2024,3,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:sec id=\"sc_a1\">\n<jats:title>OBJECTIVE<\/jats:title>\n<jats:p>Feline infectious peritonitis is fatal, and due to lack of approved treatments, unregulated antiviral drugs are used to treat this disease. This study set out to determine the purity of various batches of these drugs from several companies, characterize them, and note any impurities or other unusual characteristics. We also developed a method to qualitatively assess the primary components before administration.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sc_a2\">\n<jats:title>SAMPLES<\/jats:title>\n<jats:p>We tested 30 vials from 17 brands of GS-441524 and 5 vials from 1 brand of GC376. We compared the GS-441524 to a control standard from Ambeed and the GC376 to a standard from Cayman Chemical.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sc_a3\">\n<jats:title>METHODS<\/jats:title>\n<jats:p>We recorded physical appearance, pH, absorbance, HPLC retention times, and thin-layer chromatography retention factors for all of the samples. Some samples were used for nuclear magnetic resonance and mass spectrometric analysis.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sc_a4\">\n<jats:title>RESULTS<\/jats:title>\n<jats:p>Some of the GS-441524 vials were 10% to 25% more concentrated than advertised, but most of the GS-441524 samples tested were similar in purity and composition, both between batches and between brands. We also tested 5 vials of GC376 and found that 1 of the 5 vials contained GS-441524 rather than GC376 and the other 4 vials contained molnupiravir.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sc_a5\">\n<jats:title>CLINICAL RELEVANCE<\/jats:title>\n<jats:p>While all of the GS-441524 vials contained GS-441524, none of the GC376 vials tested contained GC376. GC376 is used in cats that are unresponsive to GS-441524, and use of the wrong antiviral can cause serious side effects. We provide suggested methods for distinguishing one drug from the other in new batches.<\/jats:p>\n<\/jats:sec>","DOI":"10.2460\/ajvr.23.10.0221","type":"journal-article","created":{"date-parts":[[2024,1,25]],"date-time":"2024-01-25T13:44:06Z","timestamp":1706190246000},"source":"Crossref","is-referenced-by-count":11,"title":["Quality assessment and characterization of unregulated antiviral drugs for feline infectious peritonitis: implications for treatment, safety, and efficacy"],"prefix":"10.2460","volume":"85","author":[{"given":"Aidan J.","family":"Mulligan","sequence":"first","affiliation":[{"name":"Juan Diego Catholic High School, Draper, UT"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Megan E.","family":"Browning","sequence":"additional","affiliation":[{"name":"Department of Medicinal Chemistry, School of Pharmacy, University of Utah, Salt Lake City, UT"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1272","reference":[{"key":"B1","series-title":"Vet Microbiol","first-page":"108777","article-title":"Coronaviruses in cats and other companion animals: where does SARS-CoV-2\/COVID-19 fit?","volume":"247","author":"Stout AE","year":"2020","unstructured":"Stout AE, Andr\u00e9 NM, Jaimes JA, Millet JK, Whittaker GR. Coronaviruses in cats and other companion animals: where does SARS-CoV-2\/COVID-19 fit? Vet Microbiol. 2020;247:108777. doi:10.1016\/j.vetmic.2020.108777"},{"issue":"14","key":"B2","series-title":"J Virol","first-page":"7577","article-title":"A human coronavirus responsible for the common cold massively kills dendritic cells but not monocytes","volume":"86","author":"Mesel-Lemoine M","year":"2012","unstructured":"Mesel-Lemoine M, Millet J, Vidalain PO, et al. A human coronavirus responsible for the common cold massively kills dendritic cells but not monocytes. J Virol. 2012;86(14):7577\u20137587. doi:10.1128\/JVI.00269-12"},{"issue":"3","key":"B3","series-title":"J Infect Dis","first-page":"344","article-title":"Alpha to omicron: disease severity and clinical outcomes of major SARS-CoV-2 variants","volume":"227","author":"Esper FP","year":"2023","unstructured":"Esper FP, Adhikari TM, Tu ZJ, et al. Alpha to omicron: disease severity and clinical outcomes of major SARS-CoV-2 variants. 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Serological survey of retrovirus and coronavirus infections, including SARS-CoV-2, in rural stray cats in The Netherlands, 2020\u20132022. Viruses. 2023;15(7):1531. doi:10.3390\/v15071531"},{"issue":"14","key":"B6","series-title":"Animals (Basel)","first-page":"1864","article-title":"Molecular detection of feline coronavirus in captive non-domestic felids from zoological facilities","volume":"12","author":"Ratti G","year":"2022","unstructured":"Ratti G, Stranieri A, Giordano A, et al. Molecular detection of feline coronavirus in captive non-domestic felids from zoological facilities. Animals (Basel). 2022;12(14):1864. doi:10.3390\/ani12141864"},{"issue":"2","key":"B7","series-title":"J Wildl Dis","first-page":"408","article-title":"Feline infectious peritonitis in a mountain lion (Puma concolor), California, USA","volume":"49","author":"Stephenson N","year":"2013","unstructured":"Stephenson N, Swift P, Moeller RB, Worth SJ, Foley J. 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Unlicensed molnupiravir is an effective rescue treatment following failure of unlicensed GS-441524-like therapy for cats with suspected feline infectious peritonitis. Pathogens. 2022;11(10):1209. doi:10.3390\/pathogens11101209"},{"key":"B21","series-title":"Front Vet Sci","first-page":"1002488","article-title":"Effect of GS-441524 in combination with the 3C-like protease inhibitor GC376 on the treatment of naturally transmitted feline infectious peritonitis","volume":"9","author":"Lv J","year":"2022","unstructured":"Lv J, Bai Y, Wang Y, Yang L, Jin Y, Dong J. Effect of GS-441524 in combination with the 3C-like protease inhibitor GC376 on the treatment of naturally transmitted feline infectious peritonitis. Front Vet Sci. 2022;9:1002488. doi:10.3389\/fvets.2022.1002488"},{"issue":"1","key":"B22","series-title":"Acta Pharmacol Sin","first-page":"255","article-title":"Structure basis for inhibition of SARS-CoV-2 by the feline drug GC376","volume":"44","author":"Luan XD","year":"2023","unstructured":"Luan XD, Chen BX, Shang WJ, et al. Structure basis for inhibition of SARS-CoV-2 by the feline drug GC376. Acta Pharmacol Sin. 2023;44(1):255\u2013257. doi:10.1038\/s41401-022-00929-z"},{"key":"B23","series-title":"Front Chem","first-page":"852210","article-title":"Crystallization of feline coronavirus Mpro with GC376 reveals mechanism of inhibition","volume":"10","author":"Lu J","year":"2022","unstructured":"Lu J, Chen SA, Khan MB, et al. Crystallization of feline coronavirus Mpro with GC376 reveals mechanism of inhibition. Front Chem. 2022;10:852210. doi:10.3389\/fchem.2022.852210"},{"issue":"29","key":"B24","series-title":"Proc Natl Acad Sci USA","first-page":"e2101555118","article-title":"Postinfection treatment with a protease inhibitor increases survival of mice with a fatal SARS-CoV-2 infection","volume":"118","author":"Dampalla CS","year":"2021","unstructured":"Dampalla CS, Zheng J, Perera KD, et al. Postinfection treatment with a protease inhibitor increases survival of mice with a fatal SARS-CoV-2 infection. Proc Natl Acad Sci USA. 2021;118(29):e2101555118. doi:10.1073\/pnas.2101555118"},{"issue":"5","key":"B25","series-title":"J Vet Intern Med","first-page":"1772","article-title":"Outcomes of treatment of cats with feline infectious peritonitis using parenterally administered remdesivir, with or without transition to orally administered GS-441524","volume":"37","author":"Coggins SJ","year":"2023","unstructured":"Coggins SJ, Norris JM, Malik R, et al. Outcomes of treatment of cats with feline infectious peritonitis using parenterally administered remdesivir, with or without transition to orally administered GS-441524. J Vet Intern Med. 2023;37(5):1772\u20131783. doi:10.1111\/jvim.16803"},{"key":"B26","article-title":"The ins and outs of extra-label drug use in animals: a resource for veterinarians","unstructured":"The ins and outs of extra-label drug use in animals: a resource for veterinarians. FDA. June 2, 2023. Accessed November 21, 2023. https:\/\/www.fda.gov\/animal-veterinary\/resources-you\/ins-and-outs-extra-label-drug-use-animals-resource-veterinarians"},{"issue":"8","key":"B27","series-title":"Animals","first-page":"2257","article-title":"Unlicensed GS-441524-like antiviral therapy can be effective for at-home treatment of feline infectious peritonitis","volume":"11","author":"Jones S","year":"2021","unstructured":"Jones S, Novicoff W, Nadeau J, Evans S. 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