Sensitive radioimmunoassay for vancomycin

Abstract

A radioimmunoassay for vancomycin has been developed which uses rabbit antiserum induced by vancomycin-bovine serum albumin conjugates and vancomycin labeled with 3H or 125I. Using either isotope, the method is simple and reproducible and has a sensitivity of 4 or 0.04 ng/ml, depending on the tracer used. This is 200- to 20,000-fold improvement in sensitivity compared with the most sensitive bioassay. Drug levels in serum or urine samples from patients receiving vancomycin can be determined by this assay procedure without processing. The data obtained with 3H and 125I labels were in good agreement. Patients' plasma vancomycin concentrations determined by radioimmunoassay correlated well with those determined by bioassay when the drug was administered intravenously. However, after oral administration the drug could be detected only by radioimmunoassay. The antiserum was evaluated for cross-reactivity with a wide variety of antibiotics and cancer chemotherapeutic agents, and no significant interference was found.

Effects of hepatic function on vancomycin clinical pharmacology

“…Preparation of vancomycin-bovine serum albumin conjugates for rabbit antiserum production, iodination of the drug, and the assay for drug content in patient samples have been previously described (6). Patients receiving vancomycin alone for their infections had similar plasma concentrations when measured by radioimmunoassay or microbiological assay.…”

“…However, the microbiological assay could not be used in patients who had received other types of antibiotics which interfered in the vancomycin assay. The radioimmunoassay showed no cross-reactivity to other drugs administered to these patients (6). In brief, the radioimmunoassay mixture contained 0.1 ml each of 0.01 M phosphate-buffered saline, pH (17).…”

Determination of vancomycin in human serum by high-pressure liquid chromatography

“…We found our HPLC method to be specific. HPLC has been reported to be more specific than RIA in monitoring vancomycin (13). This lower specificity of RIA may in part explain the overestimation, as many samples used for the correlation study were known to contain high concentrations of many drugs, including betalactam antibiotics.…”

“…Radioimmunoassay (RIA) and fluorescent polarization immunoassay (FPIA) have been developed (1,13), and two chromnatographic procedures have also been described (19,26 (9,10, and 81%). Glacial acetic acid was added to adjust the pH to 5.4, and the entire mixture was then filtered through a 0.22-,um-pore-size filter.…”

Analytical methods for vancomycin determination in biological fluids and in pharmaceuticals

“…The RIA method [34][35][36][37] had also been employed. Despite the good quality of the analytical results, it is less efficient and more expensive than FPIA, and there is also the disadvantage of using radioactive substances 37 .…”