Comparison of an injectable toltrazuril–gleptoferron and an oral toltrazuril + injectable gleptoferron in piglets: Hematinic activities and pharmacokinetics

Abstract Iron deficiency anemia (IDA) and cystoisosporosis are the most common clinical conditions of fast‐growing piglets. Until now, IDA and cystoisosporosis have been managed by intramuscular injection of iron complexes (such as dextran or gleptoferron) and oral administration of toltrazuril. Recently, a new combination product containing toltrazuril and gleptoferron for intramuscular application (Forceris®) has been registered. The objective of this study was to compare the pharmacokinetic profiles of toltrazuril and its main metabolite, toltrazuril sulfone, following a single oral (Baycox®) or intramuscular (Forceris®, a toltrazuril‐iron combination product) administration at 20 mg/kg to young suckling piglets. The orally treated piglets were also supplemented with iron (Gleptosil®), and the hematinic activities were compared. Piglets in both groups received comparable doses. The peak concentration (C max ) of toltrazuril after intramuscular administration was 11% lower than that after oral administration ( p = .376). However, the exposure to toltrazuril (AUC) was significantly increased (40% higher) when toltrazuril was administered intramuscularly ( p = .036). The C max and AUC values of the active metabolite, toltrazuril sulfone were 39% and 34% higher, respectively, after intramuscular administration ( p = .007 and 0.008, respectively). Piglets in both groups were properly protected against IDA. In conclusion, a higher relative bioavailability of toltrazuril is observed when toltrazuril is administered intramuscularly.