"Estimates of the pharmacokinetics of famciclovir and its active metabo" by A. Paige Brock Dr., Ramiro Isaza et al.
 

Title

Estimates of the pharmacokinetics of famciclovir and its active metabolite penciclovir in young Asian elephants (Elephas maximus)

Abstract

Objective: To determine plasma pharmacokinetics of penciclovir following oral and rectal administration of famciclovir to young Asian elephants (Elephas maximus).

Animals: 6 healthy Asian elephants (5 females and 1 male), 4.5 to 9 years old and weighing 1,646 to 2,438 kg.

Procedures: Famciclovir was administered orally or rectally in accordance with an incomplete crossover design. Three treatment groups, each comprising 4 elephants, received single doses of famciclovir (5 mg/kg, PO, or 5 or 15 mg/kg, rectally); there was a minimum 12-week washout period between subsequent famciclovir administrations. Serial blood samples were collected after each administration. Samples were analyzed for famciclovir and penciclovir with a validated liquid chromatography-mass spectroscopy assay.

Results: Famciclovir was tolerated well for both routes of administration and underwent complete biotransformation to the active metabolite, penciclovir. Mean maximum plasma concentration of penciclovir was 1.3 μg/mL at 1.1 hours after oral administration of 5 mg/ kg. Similar results were detected after rectal administration of 5 mg/kg. Mean maximum plasma concentration was 3.6 μg/mL at 0.66 hours after rectal administration of 15 mg/ kg; this concentration was similar to results reported for humans receiving 7 mg/kg orally.

Conclusions and Clinical Relevance: Juvenile Asian elephants are susceptible to elephant endotheliotropic herpesvirus. Although most infections are fatal, case reports indicate administration of famciclovir has been associated with survival of 3 elephants. In Asian elephants, a dose of 8 to 15 mg of famciclovir/kg given orally or rectally at least every 8 hours may result in penciclovir concentrations that are considered therapeutic in humans.

Department(s)

Animal Science

Document Type

Article

DOI

https://doi.org/10.2460/ajvr.73.12.1996

Publication Date

12-1-2012

Journal Title

American Journal of Veterinary Research

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