Pharmacokinetics and residue elimination of norfloxacin in rainbow trout (Oncorhynchus mykiss)

Abstract

We studied the metabolism and elimination of norfloxacin in rainbow trout (Oncorhynchus mykiss) following a single oral administration of 50 mg/kg at 15 ± 2°C.Norfloxacin was measured by high-performance liquid chromatography-tandem mass spectrometry in plasma, muscle, liver, kidney, skin and remainder tissues, and the concentrationtime curve was characterized by a double peak. The drug was absorbed rapidly; the first peak appeared within 4 h, and the second peak appeared within 24 h in all substrates tested. The maximal concentrations in plasma, muscle, liver and kidney were 0.468 mg/L, 14.146 mg/kg, 6.445 mg/kg and 0.977 mg/kg, respectively.The distribution half-life was 5.814, 9.026, 17.027 and 1.004 h, respectively. The elimination half-life was 41.205, 41.667, 44.896 and 54.908 h, respectively. Using the kidney as the reference tissue for norfloxacin monitoring in aquaculture and 2 μg/ kg as a maximum residue limit standard, it takes 555 temperature-day (°C days) for norfloxacin to be completely eliminated from rainbow trout.

Effect of flowing water on the pharmacokinetic properties of norfloxacin in channel catfish (Ictalurus punctatus) after single‐dose oral administration

“…This study evaluated the effects of flowing water on the pharmacokinetics and tissue distribution of NOR in channel catfish. In another study, the haemolymph concentration-time profile of NOR in the Pacific white shrimp (Litopenaeus vannamei) presented two peaks (Fang and Zheng 2006), whereas in the present study, the NOR concentration (μg/kg) in the liver of fish reared in the RAS presented three (Oncorhynchus mykiss) (Wang et al, 2022). These reports indicate that the pharmacokinetic characteristics of NOR vary by species, perhaps because of differences in anatomical volumes and the binding of drugs to plasma proteins and to tissues (Barron et al, 1988;Chen et al, 2011).…”

“…In another study, the haemolymph concentration–time profile of NOR in the Pacific white shrimp ( Litopenaeus vannamei ) presented two peaks (Fang and Zheng 2006 ), whereas in the present study, the NOR concentration (μg/kg) in the liver of fish reared in the RAS presented three peaks: 1894 μg/kg at 0.5 h, 56,624 μg/kg at 2 h and 2506 μg/kg at 24 h. The NOR concentration in the plasma of fish grown in the FAS peaked at 1, 24 and 96 h after treatment, corresponding to 5893.15, 148.92 and 8.95 μg/L, respectively, and NOR levels in the kidney of fish kept in the FAS peaked at 2 and 8 h, corresponding to 14,173.42 and 18,389.25 μg/kg, respectively. Meanwhile, the double peak phenomenon has also been reported in NOR in Songpu Mirror Carp( Cyprinus carpio specularis ) (Hao et al., 2017 ) and rainbow trout ( Oncorhynchus mykiss ) (Wang et al., 2022 ). These reports indicate that the pharmacokinetic characteristics of NOR vary by species, perhaps because of differences in anatomical volumes and the binding of drugs to plasma proteins and to tissues (Barron et al., 1988 ; Chen et al., 2011 ).…”

“…In the RAS, the values were 4 days longer than those in the FAS. In another study, the muscle of rainbow trout exhibited a withdrawal time of 8 days post-administration at a dose of 50 mg/kg (at 15 • C) (Wang et al, 2022). In addition, Wang et al (2008) reported a withdrawal time of 19 and 32 days for NOR in the muscle of Japanese sea perch and black sea bream following a treatment dose of 30 mg/kg per day for 5 days at 18 and 16 • C, respectively.…”

“…In the RAS, the values were 4 days longer than those in the FAS. In another study, the muscle of rainbow trout exhibited a withdrawal time of 8 days post‐administration at a dose of 50 mg/kg (at 15°C) (Wang et al., 2022 ). In addition, Wang et al.…”