Pharmacokinetics of a Single Oral Dose of Ponazuril in the Indian Peafowl (Pavo Cristatus)

The Pharmacokinetics and Pharmacodynamics of Oral Ponazuril in the Treatment of Systemic Isosporosis in Passerine Birds

“…Absorption half-life (28.4 h for gavage group and 26.2 h for top-dressed feed group) was significantly longer than elimination half-life (0.87 h for the gavage group and 3.41 for the top-dressed feed group) in these starlings. 5,13,24,33,41,42 This phenomenon, referred to as the flip-flop effect, means the shape of the elimination curves shown in the figures from this study is affected more by the slow absorption rate than by the elimination rate, but IV administration was not performed, which is needed to confirm the suspected flip-flop effect. 40 Multidose ponazuril pharmacokinetic studies have not been performed in avian species previously but have been performed in the domestic horse (Equus ferus) at a daily oral dose of 5 mg/kg for 28 d. 15 After 5 d of treatment, serum ponazuril concentrations in the horses had reached 4.33 lg/ ml, lower than the concentrations achieved in the European starlings in the top-dressed feed group (9.13 lg/ml).…”

“…5,13,24,33,41,42 The elimination half-life of ponazuril in the plasma of European starlings (5.84 h) was significantly shorter than that observed in Indian peafowl (18.4242 lg/ml), cattle (58 h), goats (129 h), llamas (135 h), and pigs (135 h). 5,13,24,33,41,42 The reason for these differences is undetermined.…”

“…The single-dose pharmacokinetics of ponazuril has been described in a variety of species, including cattle ( Bos taurus ), goats ( Capra hircus ), llamas ( Lama glama ), pigs ( Sus domesticus ), red-footed tortoises ( Chelonoidis carbonarius ), and Indian peafowl ( Pavo cristatus ). 5,13,24,33,41,42 Dosages used in these studies have ranged from 5 to 40 mg/kg of ponazuril for oral administration. The T max for European starlings (4.51 h) was significantly shorter compared with Indian peafowl (22 h), goats (36 h), pigs (42 h), cattle (48 h), llamas (84 h), and red-footed tortoises (144 h).…”

“…The T max for European starlings (4.51 h) was significantly shorter compared with Indian peafowl (22 h), goats (36 h), pigs (42 h), cattle (48 h), llamas (84 h), and red-footed tortoises (144 h). 5,13,24,33,41,42 Peak plasma ponazuril concentrations in the starlings (5.84 µg/ml for gavage and 9.13 µg/ml for top-dressed feed) were lower than those reported in Indian peafowl (18.42 µg/ml) and llamas (23.6 µ/ml) but similar to those measured in red-footed tortoises (3.21 µg/ml), cattle (4.821 µg/ml), goats (9 µg/ml), and pigs (5.83 µg/ml). 5,13,24,33,41,42 The elimination half-life of ponazuril in the plasma of European starlings (5.84 h) was significantly shorter than that observed in Indian peafowl (18.4242 µg/ml), cattle (58 h), goats (129 h), llamas (135 h), and pigs (135 h).…”

Pharmacokinetics, bioavailability, and excretion of ponazuril in piglets

“…Zec et al reported that ponazuril in peafowl was absorbed orally with C max of 11.82 μg/mL and 18.42 μg/mL for 20 and 40 mg/kg doses, respectively. But the increase in plasma concentration and AUC were not proportional to a doubling of the dose, indicating potential nonlinear absorption in these birds ( 37 ). From the present study in piglets, ponazuril peaked at about 48 h after a single oral dose of 20 mg/kg bw with a mean concentration of 18 μg/mL.…”