Pharmacokinetic and tissue distribution study of oxytetracycline in rainbow trout following bolus intravenous administration

Abstract

Oxytetracycline pharmacokinetics and tissue distribution were studied in rainbow trout following bolus i.v. administration at 5 mg/kg. The mean serum (log) drug concentration data were plotted against time (linear). The decay curve was described by a three-component exponential decay function and a three-compartment model. The t1/2 of rapid distribution was 0.9 h, the t1/2 of the slow distribution was 5.9 h and the t1/2 elimination was 81.5 h. Clearance was 25.4 ml/kg/h and Vd(area) 2988 ml/kg. Regression analysis of the serum levels for the three intervals, 0.5-2.0 h, 6.0-18.0 h, and 24-96 h, indicated that the rates of decay for each interval were 0.6151 h-1, 0.0564 h-1 and 0.0088 h-1 respectively. Rates of equilibration between tissues and serum were determined. Kidney equilibrated the fastest with t1/2 to equilibration of 1.1 h for H (anterior) kidney and 1.98 h for P (posterior) kidney. The highest drug levels were found in the liver and the lowest were in the brain.

A comparative tissue distribution study of oxytetracycline in rainbow trout,Oncorhynchus mykiss(Walbaum), and chinook salmon,Oncorhynchus tshawytscha(Walbaum)

“…Previous studies have shown that OTC has a relatively large volume of distribution in the salmonids ( Grondel et al . 1989 ; Björklund & Bylund 1991; Black et al . 1991 ; Abedini et al .…”

Study of the Nervous Tissue Development in Rainbow Trout (Oncorhynchus mykiss) Embryos Treated with Oxytetracycline

“…Studies in rainbow trout have been conducted at numerous water temperatures, in fish of various sizes and via both enteral and parenteral routes. The highest organ drug concentrations were found in liver, gills, kidney and gonad (Black et al., 1991). Because OTC is bacteriostatic and not bactericidal, careful conditions regarding the prolonged administration of these tetracycline chemotherapeutic agents are essential, especially when the immune system of the fish may already be compromised by environmental conditions, husbandry techniques and infectious diseases (Grondel and Boesten, 1982).…”

Oxytetracycline depletion and withdrawal time estimation following intraperitoneal administration in three species from Chilean salmon farming

“…In general, the T½ estimations for all trials were between 12 and 19.8 days post injection, except for T‐1 and T‐3 of Rainbow trout under controlled conditions. From a review of previous studies, a great variation in T½ estimations was observed, ranging from 2 to 15 days (Black, Ferguson, Byrne & Claxton, ; Meinertz et al., ; Namdari, Abedini & Law, , ). It is important to note that most of the studies reviewed showed T½ values around 5 days, and only one work showed a T½ of 15 days (Namdari et al., ), being the later carried out for rainbow trout and Chinook salmon after the administration of intravenous OTC at doses of 50 and 5 mg/kg, respectively.…”