Pharmacokinetics of altrenogest after oral dosing in healthy nulliparous sows

Author: 
Gonzalo López Rincón., Elba M. Romero Tejeda., Eligio R. Moreno-Gómez., Leonel Avendaño Reyes and Guillermo Oregel Ramírez

Background: The Altrenogest has been widely used to induce estrus synchronization in gilts, but there are no data on the pharmacokinetics profile as a method for synchronization on commercial pig farms. The purpose of this study was to determine the pharmacokinetic profile after 18 oral doses of 20 mg Altrenogest/gilts/day at an interval of 24 h. Material and methods: Blood samples from each gilt were collected before (0 h) and after drug administration at 20 different time points between 1–504 h. Plasma samples were collected, and drug plasma concentrations were determined by a validated high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method. Non-compartmental pharmacokinetic analysis was performed using Kinetica® version 5.1 software. Results: After the first administration (D1), the pharmacokinetics parameters, including Cmax, AUCtot and AUClast, and Vss, were statistically significantly lower that after multiple doses in gilts D9 and D18 (p ≤ 0.05). Others parameters, Tmax and T1/2z, were similar to those observed after the final administration D18 (p ≥ 0.05). Conclusion: The results revealed that Altrenogest plasma concentretion show significant accumulations over the time of treatment. The fluctuation might be caused by Altrenogest liposolubility according to different physiological stages and body weigh especially in nulliparous sows. However, further research is required in this area in order to determine Altrenogest pharmacokinetic parameters according to synchronization protocol on commercial pig farms.

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DOI: 
http://dx.doi.org/10.24327/ijcar.2021.4879.24584
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