Farmacocinética y eficacia clínica del trianfenicol en pollo de engorda

Abstract

PHARMACOKINETIC VARIABLES OF THIAMPHENICOL (TF) WERE STUDIED, AS WELL AS THE CLINICAL EFFICACY IN FIELD OUTBREAKS OF CHRONIC RESPIRATORY DISEASE (CRD) IN POULTRY. TO ESTIMATE THE PHARMACOKINETICS OF TF, 60 ARBOR ACRESS BROILERS WITH AN AVERAGE WEIGHT OF 500 G WERE USED. ANIMALS WERE DIVIDED IN 3 GROUPS: GROUP 1, RECEIVED IV A SINGLE BOLUS DOSE OF 20 MG/KG OF TF; GROUP 2, 20 MG/KG OF TF MIXED WITH FOOD; AND GROUP 3, 20 MG/KG OF TF DISSOLVED IN THE DRINKING WATER. ALL GROUPS WERE BLED AT DIFFERENT TIMES TO DETERMINE TF IN PLASMA ACCORDING WITH A STANDARDIZED AGAR DIFFUSION MICROBIOLOGICAL TEST. THE COMPARATIVE CLINICAL EFFICACY OF TF WAS EVALUATED IN FIELD OUTBREAKS OF CRD COMPLICATED WITH E. COLI VS THE STANDARD TREATMENT ADMINISTERED IN THE CORRESPONDING FARM. ALL 49,000 3 WEEK OLD BROILERS WERE TREATED EITHER WITH TF IN THE WATER OR WITH OTHER ANTIMICROBIALS. PRODUCTIVE PARAMETERS WERE RECORDED. PHARMACOKINETIC VALUES REVEALED BOTH HIGH BIOAVAILABITY (80%) AND APPARENT VOLUME OF DISTRIBUTION AREA UNDER CURVE (AUC) (2.8 1 KG). THIS LATTER FEATURE ENSURES HIGH TISSUE PENETRATION. CPMAX VALUES WERE: 2.8 mG/ML IN THE GROUP MEDICATED WITH TF IN WATER, AND 9.7 mG/ML IN THE GROUP MEDICATED WITH TF IN WATER, AND 9.7 mG/ML IN THE FEED-TREATED GROUP. TERMINAL HALF LIFE (T1/2 b= 1.7 H) SUGGESTS THAT A 24 HOUR DOSING INTERVAL COULD BE APPROPRIATE, AND THEREFORE, SUGGEST A MINIMUM OF 48 H OF A WITHDRAWAL PERIOD.