methylene blue antidote cyanide poisoning

There is no evidence for administering doses of hydroxocobalamin higher than 150 mg/kg. For this reason, we propose a dose of 70 mg/kg hydroxocobalamin, to be repeated if persistent signs of toxicity exist. This monotherapy of hydroxocobalamin should be effective for severe cyanide toxicity, provided it is administered in sufficiently high doses. In our guidelines, we focus on the fast-acting hydrogen cyanide and advocate the use of hydroxocobalamin as a first-line antidote. The limitations to this study are the duration of the study model (limited to 60 min after the start of cyanide infusion) and the hemodynamic parameters as end points, instead of long-term sequelae 1,2,4 1,2,4 1,2,4. 4 have shown that sodium thiosulfate added to hydroxocobalamin shows no benefit for cyanide-induced shock in a swine model. The only limitation is that sodium thiosulfate and hydroxocobalamin may not be mixed in the same vial because this induces the formation of inefficient thiosulfatocobalamin 3.Īlthough there may be a theoretically synergistic action of sodium thiosulfate and hydroxocobalamin in cyanide toxicity, there is no evidence to support this at the moment, either in human data, or in animal data. Hydroxocobalamin and sodium thiosulfate can be combined safely. Therefore, theoretically, there is a synergistic action of sodium thiosulfate and hydroxocobalamin 1,2 1,2. Sodium thiosulfate acts as a sulfur donor to detoxify cyanide to thiocyanate by the enzyme rhodanese, whereas hydroxocobalamin binds cyanide and forms the nontoxic cyanocobalamin, which is renally excreted.

Its use as a single antidote for acute cyanide toxicity is no longer supported or indicated 1,2 1,2.īecause of its immediate diffusion into the different tissue compartments, intravenously administered hydroxocobalamin has a rapid onset of action. We wish to thank Bebarta for drawing our attention to the position of sodium thiosulfate in the treatment of cyanide toxicity and giving us the opportunity to clarify our statements.Īlthough sodium thiosulfate is considered an ineffective antidote for acute cyanide toxicity because of poor intracellular penetration, slow onset of effect, a short half-life, and limited distribution volume, it is often used in conjunction with other rapid-acting antidotes.

Methylene blue antidote cyanide poisoning