FORMATION OF FERRIHAEMOGLOBIN WITH AMINOPHENOLS IN HUMAN FOR TREATMENT OF CYANIDE POISONING

Experiments with several aminophenols showed that 4-dimethylaminophenol and 4-methylaminophenol most rapidly produced controlled amounts of ferrihaemoglobin in the blood of various species in vitro and in vivo. The rapid reaction of 4-dimethylaminophenol and 4-methylaminophenol was also observed after intravenous injection in humans. Doses which oxidize 30 to 40% of the haemoglobin produce the half-maximal ferrihaemoglobin concentration in 1 and 2 min respectively without any immediate effect on the cardiovascular system. Sodium nitrite in doses of 4 mg/kg recommended for the treatment of cyanide poisoning was found to oxidize slowly about 7% of the haemoglobin, 10 min being taken for producing half the maximal amount of ferrihaemoglobin, i.e. 3.5% of the total haemoglobin. Nitrite caused a decrease in arterial blood pressure in all experiments and orthostatic collapse of several test persons. The rate of ferrihaemoglobin reduction in humans was determined. An amount of ferrihaemoglobin equal to about 8% of the total haemoglobin is reduced each hour, when the ferrihaemoglobin concentration amounts to more than 10% of the total haemoglobin. © 1969.