Objective—To determine the pharmacokinetics of
fluconazole in horses.
Animals—6 clinically normal adult horses.
Procedure—Fluconazole (10 mg/kg of body weight)
was administered intravenously or orally with 2
weeks between treatments. Plasma fluconazole concentrations
were determined prior to and 10, 20, 30,
40, and 60 minutes and 2, 4, 6, 8, 10, 12, 24, 36, 48,
60, and 72 hours after administration. A long-term oral
dosing regimen was designed in which all horses
received a loading dose of fluconazole (14 mg/kg) followed
by 5 mg/kg every 24 hours for 10 days.
Fluconazole concentrations were determined in aqueous
humor, plasma, CSF, synovial fluid, and urine after
administration of the final dose.
Results—Mean (± SD) apparent volume of distribution
of fluconazole at steady state was 1.21 ± 0.01
L/kg. Systemic availability and time to maximum plasma
concentration following oral administration were
101.24 ± 27.50% and 1.97 ± 1.68 hours, respectively.
Maximum plasma concentrations and terminal halflives
after IV and oral administration were similar.
Plasma, CSF, synovial fluid, aqueous humor, and urine
concentrations of fluconazole after long-term oral
administration of fluconazole were 30.50 ± 23.88,
14.99 ± 1.86, 14.19 ± 5.07, 11.39 ± 2.83, and 56.99 ±
32.87 µg/ml, respectively.
Conclusion and Clinical Relevance—Bioavailability
of fluconazole was high after oral administration to
horses. Long-term oral administration maintained plasma
and body fluid concentrations of fluconazole above
the mean inhibitory concentration (8.0 mg/ml) reported
for fungal pathogens in horses. Fluconazole may be
an appropriate agent for treatment of fungal infections
in horses. (Am J Vet Res 2001;62:1606–1611).
Objective—To determine clinical findings and outcome in horses treated by means of a balloon constant rate infusion system.
Design—Retrospective case series.
Procedures—Medical records of horses examined at The Ohio State University veterinary teaching hospital from 2002 to 2005 that had septic arthritis, septic tenosynovitis, or penetration of a synovial structure and in which treatment involved a balloon constant rate infusion system were searched. Information pertaining to signalment, history, physical examination findings, clinicopathologic data, treatment, and duration of hospitalization was recorded.
Results—Mean ± SD duration of hospitalization was 11.5 ± 5.26 days. No correlation between duration of clinical signs and duration of hospitalization or duration of infusion pump use was detected, but correlations between WBC count and duration of hospitalization and WBC and duration of infusion-pump use were observed. All horses survived to discharge. Follow-up information was obtained on 17 horses, 16 of which were alive at the time of follow-up. Twelve of 13 horses for which followup information was available for at least 5 months were alive 5 months or longer after discharge. Thirteen of the 16 horses alive at follow-up were reported by owners as not lame, whereas the remaining 3 were mildly lame or intermittently moderately lame or had developed angular limb deformity in the contralateral limb.
Conclusions and Clinical Relevance—Balloon constant rate infusion systems may be used effectively in treatment of septic arthritis, septic tenosynovitis, and contaminated synovial wounds. Clinical response and long-term outcome appeared to be comparable to results obtained with other techniques.
Objective—To determine the pharmacokinetics of voriconazole following IV and PO administration and assess the distribution of voriconazole into body fluids following repeated PO administration in horses.
Animals—6 clinically normal adult horses.
Procedures—All horses received voriconazole (10 mg/kg) IV and PO (2-week interval between treatments). Plasma voriconazole concentrations were determined prior to and at intervals following administration. Subsequently, voriconazole was administered PO (3 mg/kg) twice daily for 10 days to all horses; plasma, synovial fluid, CSF, urine, and preocular tear film concentrations of voriconazole were then assessed.
Results—Mean ± SD volume of distribution at steady state was 1,604.9 ± 406.4 mL/kg. Systemic bioavailability of voriconazole following PO administration was 95 ± 19%; the highest plasma concentration of 6.1 ± 1.4 μg/mL was attained at 0.6 to 2.3 hours. Mean peak plasma concentration was 2.57 μg/mL, and mean trough plasma concentration was 1.32 μg/mL. Mean plasma, CSF, synovial fluid, urine, and preocular tear film concentrations of voriconazole after long-term PO administration were 5.163 ± 1.594 μg/mL, 2.508 ± 1.616 μg/mL, 3.073 ± 2.093 μg/mL, 4.422 ± 0.8095 μg/mL, and 3.376 ± 1.297 μg/mL, respectively.
Conclusions and Clinical Relevance—Results indicated that voriconazole distributed quickly and widely in the body; following a single IV dose, initial plasma concentrations were high with a steady and early decrease in plasma concentration. Absorption of voriconazole after PO administration was excellent, compared with absorption after IV administration. Voriconazole appears to be another option for the treatment of fungal infections in horses.