Effect of procaine penicillin G and flunixin meglumine on serum amyloid A

SAA has become an important tool for identifying acute inflammation and response to treatment. In interpreting SAA values it is important to know how commonly used treatments effect the values independent of any therapeutic effects. Both penicillin and flunixin do not typically cause a rise in SAA out of reference range.
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Effect of procaine penicillin G and flunixin meglumine on serum amyloid A response in healthy adult horses
J Equine Vet Sci. 2023 Jul 12;104876. doi: 10.1016/j.jevs.2023.104876. Online ahead of print.
Authors
Jurica Trsan 1 , Bridget F Nottle 2 , Nicola Pusterla 3
Affiliations

1 William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA. Electronic address: jtrsan@ucdavis.edu.
2 William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA; Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, 80523, USA.
3 William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.

PMID: 37451522
DOI: 10.1016/j.jevs.2023.104876

Abstract

This study was designed to determine the effect of PPG and/or flunixin meglumine on SAA response when used at clinical dosing regimens in healthy adult horses. Six healthy adult horses were enrolled in a crossover study design including one control and three treatment groups: no treatment (control); PPG alone (intramuscularly q12h for 72h); flunixin meglumine alone (intravenously q24h for 72h); and PPG (intramuscularly q12h for 72h) and flunixin meglumine (intravenously q24h for 72h). Whole blood was collected at 0, 24, 48, 72, 96 and 120 hours post-initial drug administration to measure SAA using a commercial lateral-flow immunoassay. The washout period was 30 days. Individual SAA values were within the reference range (≤ 20 µg/mL) for almost all horses in the control group. One control horse displayed a SAA value of 28 µg/mL at 72 hours. All horses from the PPG group showed normal SAA values throughout the study. Apart from one horse (SAA of 24 µg/mL at 96 hours) from the flunixin meglumine group, all horses showed normal SAA values. For the PPG and flunixin meglumine group, 5 horses had SAA values within reference range. One horse displayed increased SAA values (32-45 µg/mL) between 48 to 96 hours post-drug administration. There was no difference in area under the SAA time curve amongst control and treatment groups (P > 0.05). The administration of intramuscular PPG and/or intravenous flunixin meglumine does not trigger an inflammatory response that induces a SAA value above reference range in most adult healthy horses.

Keywords: Banamine; Equine; PPG; SAA; inflammatory response.