Allometric analysis of tylosin tartrate pharmacokinetics in growing male turkeys
- Author:
Błażej POŹNIAK
1
;
Marta TIKHOMIROV
;
Karolina MOTYKIEWICZ-PERS
;
Kamila BOBREK
;
Marcin ŚWITAŁA
Author Information
- Publication Type:Original Article
- From:Journal of Veterinary Science 2020;21(3):e35-
- CountryRepublic of Korea
- Language:English
-
Abstract:
Background:Despite common use of tylosin in turkeys, the pharmacokinetic (PK) data for this drug in turkeys is limited. Within a few months of growth, PK of drugs in turkeys undergoes changes that may decrease their efficacy due to variable internal exposure.
Objectives:The objective of this study was to investigate the influence of age on the PK of a single intravenous (i.v.) and oral administration of tylosin to turkeys at a dose of 10 and 50 mg/kg, respectively.
Methods:Plasma drug concentrations were measured using high-performance liquid chromatography with UV detection. The PK parameters were assessed by means of non-compartmental approach and were subjected to allometric analysis.
Results:During a 2.5-month-long period of growth from 1.4 to 14.7 kg, the median value for area under the concentration-time curve after i.v. administration increased from 2.61 to 7.15 mg × h/L and the body clearance decreased from a median of 3.81 to 1.42 L/h/kg. Over the same time, the median elimination half-life increased from 1.03 to 2.96 h. For the oral administration a similar trend was noted but the differences were less pronounced. Bioavailability was variable (5.76%–21.59%) and age-independent. For both routes, the plasma concentration of the major tylosin metabolite, tylosin D, was minimal. Protein binding was age-independent and did not exceed 50%. Allometric analysis indicated a relatively poor predictivity of clearance, volume of distribution and elimination half-life for tylosin in turkeys.
Conclusions:Age has a significant impact on tylosin PK in turkeys and dosage adjustment may be needed, particularly in young individuals.
