EFFECT OF THE CYANIDE ANTIDOTE HYDROXOCOBALAMIN ON COMMONLY ORDERED SERUM CHEMISTRY STUDIES

Study hypothesis: Concentrated aqueous solutions of hydroxocobalamin ( OHCob) are given intravenously for the treatment of cyanide poisoning. Because OHCob solutions are intensely red and have peak light absorpt ions at 352 nm and 525 nm, we investigated whether the presence of OHC ob in serum would interfere with various automated, colorimetric chemi stry measurements. Design: Selected serum chemistry colorimetric measu rements were compared in seven patients, using their own serum as cont rol, with serum containing OHCob at the following concentrations: 100 mg/L, 500 mg/L, and 1,000 mg/L. These concentrations are in the range achieved with therapeutic doses of OHCob when given for cyanide poison ing. Measurements and main results: Statistically significant alterati ons in serum values for aspartate aminotransferase, total bilirubin, c reatinine, magnesium, and iron were seen in the presence of OHCob. Con clusion: The presence of OHCob in serum interferes with several chemis try methodologies, and such interference should be anticipated when th is antidote is used.