Possible Interaction: Hydroxocobalamin and Nitroprusside

“These data show that hydroxocobalamin prevents cyanide transfer from red cells and plasma to tissue after nitroprusside metabolism , and thereby prevents cyanide toxicity from large intravenous doses of the drug.”

“ Hydroxocobalamin , which has a relatively high binding affinity for cyanide, has been shown to reduce cyanide levels in nitroprusside-treated patients.”

“The … of HC (…), SNP produced a severe metabolic acidosis; three of ten animals died during the infusion, an additional six within 24 h. When the 1 ∶ 5 … still three of seven animals succumbed within 24 h. The highest dose (1 ∶ 8) prevented acidosis, however three of eight animals died.”

“The ability of SNP to induce HO-1 in L6.G8 cells was reduced by coincubation with hydroxocobalamin , a known nitric oxide (NO) scavenger, suggesting that NO itself may be involved in HO-1 gene stimulation.”

“In longitudinal strips of rat gastric fundus, hydroxocobalamin (30 microM) significantly reduced relaxations to sodium nitroprusside (100 nM), nitric oxide (NO; 5 microM) and S-nitrosocysteine (3 microM), whereas responses to non-adrenergic, non-cholinergic (NANC) nerve stimulation were only slightly reduced.”

“These effects of HOCb on the pharmacodynamics and pharmacokinetics of SNP are probably due to complex formation between the two compounds.”

“ Hydroxocobalamin (vitamin B12a) infused simultaneously with nitroprusside significantly lessened the increase in cyanide levels and eliminated the development of metabolic acidosis.”

“The ability of SNP to induce HO-1 in L6.G8 cells was reduced by coincubation with hydroxocobalamin , a known nitric oxide (NO) scavenger, suggesting that NO itself may be involved in HO-1 gene stimulation.”