Pharmacokinetics of voriconazole after oral administration of single and multiple doses in African grey parrots (Psittacus erithacus timneh)

Abstract

In African grey parrots, voriconazole has dose-dependent pharmacokinetics and may induce its own metabolism. Oral administration of 12 to 18 mg of voriconazole/kg twice daily is a rational starting dose for treatment of African grey parrots infected with Aspergillus or other fungal organisms that have a minimal inhibitory concentration for voriconazole < or = 0.4 microg/mL. Higher doses may be needed to maintain plasma voriconazole concentrations during long-term treatment. Safety and efficacy of various voriconazole treatment regimens in this species require investigation.

Voriconazole

“…25,26 The pharamacokinetics of vorioconazole have been evaluated in Mallard ducks Amazon parrots (Amazona ventralis). 27,28,29,30,31,32,33,34 Oral bioavailability has been established in Mallard ducks, chickens, and pigeons at 61, 16, and 44%, respectively 27,30,32 ; it is unclear why this level is so much lower than humans (>90%).…”

Aspergillosis in Birds: An Overview of Treatment Options and Regimens

“…Adverse effects during the treatment are slight and rare and usually present as depression, hepatopathy, and polyuria. 29,37,38 Despite good compatibility, voriconazole should generally be regarded as a potential hepatotoxin; therefore, this drug therapy should be carefully monitored whether the patient shows clinical signs associated with liver dysfunction or not. In cases where adverse clinical signs are noted the anti-mycotic treatment should be discontinued or dosage reduced.…”

“…In the latter, therapeutic blood levels could be achieved only after a oral administration of 18 mg/kg BW twice a day. 37 In gyr, saker, and peregrine falcons, the effectiveness of voriconazole could be demonstrated on the basis of plasma levels and clinical signs after oral administration twice a day. 23…”

“…29,38 In African grey parrots, voriconazole is characterized by its excellent compatibility compared to other azole derivatives. 37 When voriconazole was administered at therapeutic doses, the only clinical adverse effect was temporary polyuria. 29,37 Other authors detected an increase of AST and bile acids in a small number of the cockatiels and cockatoos in their investigations.…”

“…37 When voriconazole was administered at therapeutic doses, the only clinical adverse effect was temporary polyuria. 29,37 Other authors detected an increase of AST and bile acids in a small number of the cockatiels and cockatoos in their investigations. 29 After the oral application of voriconazole at 20 mg/kg BW over a period of 12 hours in pigeons, both macroscopic and microscopic liver alterations as well as adverse clinical sings in the form of vomiting and depression were observed.…”