Pharmacokinetics of oxytetracycline in the red pacu (Colossoma brachypomum) following different routes of administration

Abstract

Oxytetracycline (OTC) pharmacokinetics were studied in the red pacu (Colossoma brachypomum) following intravenous (i.v.) and intramuscular (i.m.) administration at a dose of 5 mg/kg body weight. OTC plasma concentrations were determined by high-performance-liquid-chromatography (HPLC). A non-compartmental model was used to describe plasma drug disposition after OTC administration. Following i.m. administration, the elimination half-life (t1/2) was 62.65 +/- 1.25 h and the bioavailability was 49.80 +/- 0.01%. After i.v. administration the t1/2 was 50.97 +/- 2.99 h, the Vd was 534.11 +/- 38.58 mL/kg, and CI(b) was 0.121 +/- 0.003 mL/min x kg. The 5 mg/kg i.v. dose used in this experiment resulted in up to 48 h plasma concentrations of OTC above the reported MIC values for some strains of fish pathogens such as Aeromonas hydrophila, A. liquefaciens, A. salmonicida, Cytophaga columnaris, Edwardsiella ictaluri, Vibrio anguillarium, V. ordalii, V. salmonicida and Yeersinia ruckeri. These MIC values are below the susceptible range (4 microg/mL) listed by the National Committee for Clinical Laboratory Standards (NCCLS) as determined by the NCCLS susceptibility interpretive criteria.

Determination of oxytetracycline levels in rainbow trout serum on a biphenyl column using high-performance liquid chromatography

“…We calculated these values as the average background signal plus 3× the standard deviation (LOD) or plus 10× the standard deviation (LOQ) in analyses of rainbow trout control serum. Calculated LOD and LOQ values were lower than those reported in previous OTC pharmacokinetics studies where serum was analyzed on a C8 column (LOD = 0.05 g/mL) [16] and plasma was analyzed on a C18 column (LOQ = 0.1 g/mL) [17]. In addition, the mean percent recovery for all samples in this study (102 ± 8.34%) was greater than the same parameter measured previously by Doi et al (76.16 ± 0.14%) [16] and Haug and Hals (83.0 ± 8.9%) [17].…”

The in‐vitro antibacterial effects of organic salts, chemical disinfectants and antibiotics against pathogens of black disease in fairy shrimp of Thailand

“…OTC is used worldwide, in aquaculture and in the ornamental fish industry because of its broad spectrum of activity, low toxicity and low cost. It is licensed in the UK (Alderman & Hastings 1998) and is approved by the Food and Drug Administration (FDA) for fish production in the USA (Doi, Stoskopf & Lewbart 1998;Shao 2001;Taylor 2003). The action of this antibiotic is to bind to the 30S subunit of the microbial 70S ribosomes, which leads to the inhibition of protein synthesis by preventing the attachment of aminoacyl-tRNA units (Roberts 1996;Chopra & Roberts 2001;Miranda & Zemelman 2002).…”

Pharmacokinetics of florfenicol following intramuscular and intravenous administration in olive flounder (Paralichthys olivaceus)

“…These differences among and within species could be explained in part by environmental factors such as acclimatization temperature and salinity, which is known to play an important role in drug absorption, elimination, and metabolism in fish (Jacobsen, 1989; Luzzana et al. , 1994; Doi et al. , 1998).…”

“…In addition, the V ss of florfenicol in olive flounder was estimated to be 0.82 L ⁄ kg and it is relatively smaller than the V ss of florfenicol in Korean catfish (1.09 L ⁄ kg, Park et al, 2006), Atlantic salmon (1.12 L ⁄ kg; Horsberg et al, 1996), and cod (1.11 L ⁄ kg, Samuelsen et al, 2003). These differences among and within species could be explained in part by environmental factors such as acclimatization temperature and salinity, which is known to play an important role in drug absorption, elimination, and metabolism in fish (Jacobsen, 1989;Luzzana et al, 1994;Doi et al, 1998). Otherwise, it could be accounted for extremely low rates of active and standard metabolism of flatfish including olive flounder such as extremely limited gill surface area, small ventricular masses, and relatively low arterial blood pressure compared to other fish species (Joaquim et al, 2004).…”