Pharmacokinetic Profiles of Oxytetracycline in Yellow Perch (Perca flavescens) as Determined by Plasma Concentration Following Different Routes of Adm

Type of Document Master's Thesis
Author Bowden, Brent Christopher
Author's Email Address brbowden@vt.edu
URN etd-04182001-020709
Title Pharmacokinetic Profiles of Oxytetracycline in Yellow Perch (Perca flavescens) as Determined by Plasma Concentration Following Different Routes of Administration
Degree Master of Science
Department Veterinary Medical Sciences
Advisory Committee
Advisor Name Title
Stephen A. Smith Committee Chair
John L. Robertson Committee Member
Peter Eyre Committee Member
Keywords

* high-pressure-liquid-chromatography (HPLC)
* oxytetracycline (OTC)
* pharmacokinetic profiles
* Fish
* yellow perch

Date of Defense 2001-04-13
Availability unrestricted
Abstract

Oxytetracycline (OTC) is one of two antibiotics currently available and approved by

the U.S. Food and Drug Administration for use as a chemotherapeutic agent in food fish

and is widely used in the aquaculture industry. Previous pharmacokinetic studies of OTC

have been conducted in cold water and warm water species of fish. However, no

pharmacokinetic studies have been conducted on a cool water species such as yellow

perch (Perca flavescens). The yellow perch is a cool water game and commercial species

with high aquaculture potential. The pharmacokinetic profiles of oxytetracycline (OTC)

was determined by measuring plasma concentrations in yellow perch following

intraperitoneal (i.p.), intramuscular (i.m.), per os (p.o.), and intracardiac (i.c.)

administration at a single dose of 50 mg/kg body weight. Using a modification of a high-

performance-liquid-chromatographic (HPLC) technique, the plasma OTC concentrations

were determined for each of the four routes of administration. Plasma concentrations

were also evaluated in yellow perch exposed to a static 48-hour OTC water bath (100

mg/l). The terminal half-lives (t1/2) of OTC in yellow perch for i.p., i.m., p.o., and i.c.

administrations were 112, 124, 50, and 28 h, respectively. The t1/2 for the i.m. route of

administration was significantly longer than in any of the published i.m. OTC fish studies

to date. However, the times of maximum OTC concentration (tmax) for the i.p., i.m. and

p.o. administrations (2, 4, and 15 h, respectively) occurred relatively early in the plasma

concentration-time curves. This suggests, that in yellow perch, OTC is initially absorbed

very rapidly. The area under the plasma concentration-time curves (AUC) for the i.p.,

i.m., p.o., and i.c. routes of administration were 1718, 2659, 383, and 134 mcg·h/ml,

respectively. No OTC was detected in the plasma of yellow perch following the water

bath route of exposure. Finally, in yellow perch, effective therapy (plasma OTC

concentrations above MIC values for most bacteria pathogenic to fish – 4 mcg/ml) would

be achieved for up to 168 hours following a single i.p. or i.m. injection of 50 mg/kg and

for up to 15 hours following a single p.o dose of 50 mg/kg.

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