Antidotal administration of 4—dimethylaminophenol in cyanide intoxication and acute hemorrhage in dogs

Thirty-two mongrel dogs were divided into 4 groups.24 dogs of the 3 therapeutic groupswere inflicted with mild,medium,and severe hemorrhage through right femoral artery bleeding untilthe arterial systolic pressure dropped to 9.33,6.67 and 5.33 kPa,respectively,and then intoxicatedby intravenous NaCN 2.5mg/kg 3min after intoxication,intravenous 4-dimethylaminophenol(DMAP) 2 mg/kg was given.8 dogs of the control were inflicted with mild hemorrhage and similar-ly intoxicated,but no treatment was given.The changes of hemodynamics,blood gases andmethemoglobin were observed in the dogs.It was found that all the dogs of the control died with-in 5 min after administration of NaCN.DMAP could exert an excitatory effect on hemodynamicsand rescue the animals from death.The excitatory effect of DMAP became weaker whilehemorrhage became more severe.DMAP could further disturb the oxygen-caring capacity ofhemoglobin because of the formation of large amounts of methemoglobin when it was used as an anti-dote for cyanide intoxidation accompanied with acute hemorrhage.