Effect of heparin on radioimmunoassay of gentamicin

Analytical accuracy of determinations of aminoglycoside concentrations by enzyme multiplied immunoassay, fluorescence polarization immunoassay, and radioimmunoassay in the presence of heparin

“…The fact that we did not find inhibition with the TDx or RIA supports this conclusion. The lack of alteration in gentamicin, netilmicin, and tobramycin determinations by TDx and RIA in the presence of heparin confirms the previous observations of Schmelter et al (12) and the suggestion of Jolley et al (3) that plasma samples can be utilized for the determination of aminoglycoside concentrations by these two assay techniques.…”

“…The determination of aminoglycoside concentrations in heparinized plasma has been evaluated for some bioassays (5, 10, 11,16), radioimmunoasays (RIAs) (5,12), and the enzyme multiplied immunoassay technique (4,5,9,10,14). Gentamicin concentrations determined by bioassay have been reported to be 11.4% lower when measured in the presence of as little as 2 USP units of heparin per ml (11).…”

“…Gentamicin concentrations determined by bioassay have been reported to be 11.4% lower when measured in the presence of as little as 2 USP units of heparin per ml (11). Aminoglycoside concentration determinations by RIA, however, have not been altered by the presence of heparin (5,12). Krogstad et al (5) observed a 10% decrease in tobramycin and gentamicin concentrations when determined by the enzyme multiplied immunoassay technique with more than 10 and 100 USP units of heparin per ml, respectively.…”