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Dexamethasone and flumethasone residues in milk of intramuscularly dosed cows
Author(s) -
REDING J.,
SAHIN A.,
SCHLATTER J.,
NAEGELI H.
Publication year - 1997
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1111/j.1365-2885.1997.tb00095.x
Subject(s) - dexamethasone , chemistry , urine , intramuscular injection , dexamethasone sodium phosphate , aqueous suspension , pharmacology , chromatography , endocrinology , medicine , biochemistry , aqueous solution
A field study was performed to assess the level of drug residues in milk after therapeutic application of highly potent synthetic glucocorticoids. Dexamethasone was tested either as a crystalline suspension or as a combination of sodium phosphate and phenylpropionate esters. Intramuscular injection of these preparations in lactating dairy cows (60 μg dexamethasone/kg body wt) yielded drug residues in milk of up to 8.4 ng/mL 12 h after treatment. These dexamethasone residues fell to below 1.0 ng/mL within 3 days after treatment. Intramuscular injection of an aqueous flumethasone preparation (13.5 μg/kg body wt) produced drug residues in milk in the range of 0.7‐1.2 ng/mL 12 h after treatment, whereas flumethasone was below the detection limit of 0.23 ng/mL 2 days after administration. These results indicate that toxicologically significant residues may arise transiently in the milk during the first 2‐3 days after intramuscular injection of synthetic glucocorticoids. Urine from the same animals contained 5‐ to 50‐fold higher glucocorticoid concentrations than the corresponding milk samples. Thus, urine analysis appears to be an effective method to monitor the use of synthetic glucocorticoids in food producing animals.