Extralabel use of penicillin in food animals.
Penicillin is one of the most commonly detected drug residues in tissues and milk, and is the antimicrobial for which information is most often sought through FARAD.
Animals↗
Biomedical subjects
Arthur Craigmill
Publications and source records attributed to Arthur Craigmill.
Toxic potential of oleander derived compost and vegetables grown with oleander soil amendments.
California recycles 50% of previously disposed trash. Increased use of yardwastes and composts has raised concern about toxic materials in these products. Oleander is a toxic shrub common to CA landscapes and is frequently clipped and disposed of in greenwaste containers, resulting in concerns about the toxicity of oleander-contaminated yardwastes and composts from these wastes. Information about breakdown of oleandrin (one of the glycoside toxicants of oleander) during composting or the ability of plants to absorb this molecule has not been reported. In separate experiments, we documented the apparent first-order disappearance of oleandrin from composts of pure oleander, with a disappearance half-life of 15 d. Within 50 d, 90% of the oleandrin was removed during aerobic composting in a turned pile. In an amendment study with fresh uncomposted oleander, no oleandrin was detected in tomato and zuchinni fruit, snap beans, carrot tubers, or green lettuce. Oleandrin was found in red leaf lettuce growing in soils mulched with oleander, but oleandrin concentrations were near the detection limit of the assay. Soil from oleander mulched and amended plots contained low levels of oleandrin at the time of harvest.
California↗
Extrapolated withdrawal-interval estimator (EWE) algorithm: a quantitative approach to establishing extralabel withdrawal times.
The extralabel use of drugs can be defined as the use of drugs in a manner inconsistent with their FDA-approved labeling. The passage of the Animal Medicinal Drug Use Clarification Act (AMDUCA) in 1994 and its implementation by the FDA-Center for Veterinary Medicine in 1996 has allowed food animal veterinarians to use drugs legally in an extralabel manner, as long as an appropriate withdrawal period is established. The present study introduces and validates with simulated and experimental data the Extrapolated Withdrawal-Period Estimator (EWE) Algorithm, a procedure aimed at predicting extralabel withdrawal intervals (WDIs) based on the label and pharmacokinetic literature data contained in the Food Animal Residue Avoidance Databank (FARAD). This is the initial and first attempt at consistently obtaining WDI estimates that encompass a reasonable degree of statistical soundness. Data on the determination of withdrawal times after the extralabel use of the antibiotic oxytetracycline were obtained both with simulated disposition data and from the literature. A withdrawal interval was computed using the EWE Algorithm for an extralabel dose of 25 mg/kg (simulation study) and for a dose of 40 mg/kg (literature data). These estimates were compared with the withdrawal times computed with the simulated data and with the literature data, respectively. The EWE estimates of WDP for a simulated extralabel dose of 25 mg/kg was 39 days. The withdrawal time (WDT) obtained for this dose on a tissue depletion study was 39 days. The EWE estimate of WDP for an extralabel intramuscular dose of 40 mg/kg in cattle, based on the kinetic data contained in the FARAD database, was 48 days. The withdrawal time experimentally obtained for similar use of this drug was 49 days. The EWE Algorithm can obtain WDI estimates that encompass the same degree of statistical soundness as the WDT estimates, provided that the assumptions of the approved dosage regimen hold for the extralabel dosage regimen. Population models could be fitted to fragmentary data to predict residue concentrations in tissues, validate the EWE estimates, and obtain WDI estimates.
Algorithms↗