DISPOSITION KINETICS OF TYLOSIN TARTRATE ADMINISTERED INTRAVENOUSLY AND INTRAMUSCULARLY TO NORMAL AND WATER-DEPRIVED CAMELS

The disposition kinetics of tylosin tartrate administered intravenousl y (i.v.) at 10 mg/kg and intramuscularly (i.m.) at 20 mg/kg were studi ed in normal camels and in the same camels at the end of a 14 day wate r-deprivation period. After i.v. treatment, serum tylosin concentratio ns in the water-deprived camels were significantly higher, rate of dru g elimination was slower, the volume of distribution was significantly smaller, and total body clearance was significantly slower than in th e normal camels. On the other hand, serum drug concentrations were low er in the water deprived camels after i.m. dosing, the mean absorption time was significantly shorter and the i.m. availability was signific antly smaller than in the normal camels, Water-deprivation was thought to cause reduced rate of tylosin elimination by the liver, as was sho wn for antipyrine - a drug which is eliminated from the body exclusive ly by the liver. Redistribution of tylosin in tissues concomitant with a greater proportion of drug in blood and extracellular fluid of wate r-deprived camels was suggested as a partial explanation for the highe r serum drug levels seen after i.v. dosing. The low i.m. availability observed in the water-deprived camels implies that i.v. is the route o f choice for tylosin administration to ill, dehydrated camels.