Biochemical changes induced by two new prophylactic regimens for cyanide antagonism.

Clinical efficacy of two pretreatment regimens, sodium nitrite (SN) + hydroxylamine (HA) and SN + 4-dimethylaminophenol (DMAP) were evaluated in rats by studying various biochemical variables at different time intervals. Animals given single subcutaneous (s.c.) co-administration of SN+HA or SN+DMAP showed significantly elevated levels of blood bilirubin indicating hemolytic anemia. Increased levels of blood creatine phosphokinase (CPK), lactate dehydrogenase (LDH) and glutamic oxaloacetic transaminase (GOT) were indicative of aseptic necrosis at the injection site. On account of low methemoglobin reductase activity in human erythrocytes, a reduced sub-clinical dose of HA or DMAP is envisaged in humans.