The effect of level of feed intake on the pharmacokinetic disposition of oxfendazole in sheep

Plasma pharmacokinetics, faecal excretion and efficacy of pyrantel pamoate paste and granule formulations following per os administration in donkeys naturally infected with intestinal strongylidae

“…The gastrointestinal passage rate of digesta is affected by alteration in the quality and quantity of the feed consumed and this could confer variable absorption time and therefore bioavailability of drugs administered orally. It was indicated that variations in the quality (McKellar et al, 1993b;Knox and Steel, 1997;Oukessou and Souhaili, 1998;Gokbulut et al, 2007) and quantity (Ali and Hennessy, 1995;Lifschitz et al, 1997;McKellar et al, 2002;Gokbulut et al, 2010) could affect the bioavailability of anthelmintics in different animal species. Differences among the studies may be associated with diet type in donkeys compared with horses.…”

Effect of concentrate supplementation at pasture and inclusion of condensed tannins (Quebracho) in concentrates on lamb performance and faecal egg and worm counts

“…This was attributed to the fact that ad libitum intake increases flow rates of digesta (Grovum and Hecker, 1973) which reduces the retention time of condensed tannins in the digestive tract and renders them less effective against parasites. Increased food intake has also been considered responsible for reduced efficacy of anthelmintic drugs in sheep due to increased digesta passage rate (Ali and Hennessy, 1995). Also to note in the current study, the highest level of Quebracho inclusion (100 g/kg fresh) would have resulted in a maximum intake of 50 g Quebracho/day which based on the studies of Athanasiadou et al (2000aAthanasiadou et al ( ,b, 2001a) may not have been adequate to affect worm burdens.…”

In vivo and ex vivo uptake of albendazole and its sulphoxide metabolite by cestode parasites: relationship with their kinetic behaviour in sheep

“…Although the parent drug and its metabolites may be adsorbed to abomasal particulate material, a lower degree of adsorption for ABZSO compared to ABZ, may account for its greater availability in the fluid phase of the abomasal content. Ali & Hennessy (1995) have demonstrated that gastric secreted oxfendazole associates less extensively with abomasal than with ruminal particulate material, which may suggest that the acidic pH of the abomasum may play a role on the adsorption phenomenon. If the same is applicable to ABZSO, its higher concentrations in abomasal fluid may reflect a lower degree of adsorption compared to the parent compound, which reaches the abomasum from the rumen bound to the particulate material.…”