Can diarrhea affect the pharmacokinetics of racecadotril in neonatal calves?

This study was aimed to determine the pharmacokinetics of antisecretory-acting racecadotril, used in the treatment of diarrhea in humans and dogs, following oral administration in both neonatal calves with healthy and neonatal calves with infectious diarrhea. The study was carried out on a total of 24 Holstein calves (2-20 days), of which 6 were healthy and 18 were infectious diarrhea. Calves with infectious diarrhea were divided into 3 groups according to the infectious agent (Escherichia coli, Cryptosporidium parvum, and rotavirus/coronavirus). Racecadotril was administered orally at 2.5 mg/kg dose to calves. The plasma concentrations of racecadotril and its main active metabolite (thiorphan) were determined using HPLC-UV. The pharmacokinetic parameters were analyzed using the non-compartmental method. In healthy calves, the t1/2ʎz , Cmax , Tmax, and AUC0-12 of racecadotril were determined 4.70 h, 377 ng/ml, 0.75 h, and 1674 h × ng/ml, respectively. In the plasma of calves with infectious diarrhea, racecadotril and thiorphan were only detected at the sampling time from 0.25 to 1.5 h. As in calves with infectious diarrhea, thiorphan in plasma was only detected in healthy calves from 0.25 to 1.5 h. Racecadotril showed a large distribution volume, rapid elimination, and low metabolism to thiorphan in healthy calves.

Use of intestine-related biomarkers for detecting intestinal epithelial damage in neonatal calves with diarrhea.

OBJECTIVE: To evaluate the usefulness of intestinal biomarkers in determining the presence of intestinal epithelial damage in neonatal calves with diarrhea caused by 4 etiologic agents. ANIMALS: 40 neonatal calves that were healthy (n = 10) or had diarrhea (30). PROCEDURES: The study was a cross-sectional study. Results of hematologic analyses and serum concentrations of intestinal fatty acid-binding protein (I-FABP), liver fatty acid-binding protein (L-FABP), trefoil factor 3 (TFF-3), Claudin-3 (CLDN-3), γ-enteric smooth muscle actin (ACTG2), intestinal alkaline phosphatase (IAP), interleukin-8 (IL-8), platelet-activating factor (PAF), and leptin (LP) were compared among calves grouped according to whether they were healthy (control group; G-1) or had diarrhea caused by K99 Escherichia coli (G-2; n = 10), bovine rota- or coronavirus (G-3; 5 each), or Cryptosporidium spp (G-4; 10). RESULTS: Across the 3 time points at which blood samples were obtained and evaluated, the groups of calves with diarrhea generally had markedly higher mean serum concentrations of L-FABP, TFF-3, IAP, IL-8, and LP, compared with the control group. In addition, G-2 also consistently had markedly higher mean serum concentrations of I-FAB and ACTG2 and lower mean serum concentrations of CLDN-3, compared with the control group. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that degree of intestinal epithelial damage differed among calves grouped by the etiologic agent of diarrhea and that such damage might have been more severe in calves with diarrhea caused by K99 E coli. Additionally, our results indicated that serum concentrations of I-FABP, L-FABP, TFF-3, IAP, IL-8, ACTG2, LP, and CLDN-3 were useful biomarkers of intestinal epithelial damage in calves of the present study.