Effects of coadministration of corn oil and ponazuril

Who would have thought such a simple procedure would have such a large effect on the amount of ponazuril reaching the central nervous system which in turn is likely to more effectively treat the organism causing EPM.
DrO

J Vet Intern Med. 2020 Apr 17. doi: 10.1111/jvim.15765.
Effects of coadministration of corn oil and ponazuril on serum and cerebrospinal fluid concentrations of ponazuril in horses.
Furr M1, Kennedy T2.

Author information:
1. College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, United States.
2. Eleven Bravo LLC, Westport, Wisconson United States, United States.
Abstract
BACKGROUND:

Ponazuril is used for the treatment of equine protozoal myeloencephalitis (EPM). Coadministration of ponazuril with oil could result in higher serum and cerebrospinal fluid (CSF) concentrations of ponazuril.
HYPOTHESIS:

Coadministration of corn oil will result in higher serum and CSF concentrations of ponazuril than when ponazuril is administered alone.
ANIMALS:

Ten resident university-owned adult horses of either sex and >2 years of age.
METHODS:

Cohort study. Ponazuril oral paste (5 mg/kg BW; ponazuril treatment group (PON); n = 5), or ponazuril oral paste (5 mg/kg BW; ponazuril and oil treatment group (PONOIL; n = 5) coadministered with 2 oz of corn oil q24h for 21 days. Horses were treated once daily, for 21 days. Blood was collected on days 0, 7, 14, and 21 before dosing. In addition, CSF was collected on days 1, 7, 14, and 21. The concentration of ponazuril was determined in serum and CSF and results compared using repeated measures ANOVA.
RESULTS:

Coadministration of ponazuril with 2 oz of corn oil resulted in higher concentrations of ponazuril in serum (at steady state) than that found in horses given ponazuril alone (6.2 ± 0.9 mg/L versus 4.5 ± 1.0 mg/L; P = .004) (mean ± 1 SD). Cerebrospinal fluid concentrations of ponazuril were also greater in horses that received ponazuril and oil (0.213 mg/L ± 0.04 versus 0.162 ± 0.04 mg/L) (P = .03).
CONCLUSIONS AND CLINICAL IMPORTANCE:

Results suggest that coadministration of corn oil with ponazuril might enhance the effectiveness of treatment with ponazuril.