Two cases of fatal methemoglobinemia caused by self-poisoning with sodium nitrite

Abstract

Rationale:Sodium nitrite intoxication reportedly causes severe methemoglobinemia. Recent studies reported that most clinically significant cases resulted from intentional exposure in suicidal attempts. We describe 2 cases of severe methemoglobinemia secondary to intentional sodium nitrite intoxication in suicidal attempts.Patients concerns:A 26-year-old man and 20-year-old woman attempted suicide by taking sodium nitrite, and were brought to the emergency department.Diagnosis:The male patient collapsed at the scene. He ingested approximately 18 g of sodium nitrate, and his methemoglobin level was 90.3%. The female patient was conscious, but was cyanotic. She ingested approximately 12.5 g of sodium nitrite, and her methemoglobin level was 54.6%.Interventions:The male patient received advanced cardiac life support in the emergency department. Methylene blue was immediately administered for the female patient.Outcomes:The male patient died despite aggressive resuscitation. The female patient's cyanosis resolved, and her methemoglobin level decreased to 1.2% 3 hours later.Lessons:The immediate administration of methylene blue in severe methemoglobinemia patients prevented fatal consequences. The public should be informed about the accessibility and toxicity of sodium nitrite.

Causes of acquired methemoglobinemia – A retrospective study at a large academic hospital

“…The 6 patients with intentional nitrite use all received methylene blue therapy. Increases in suicide attempts with sodium nitrite have been reported to be increasing, in part due to online information on its toxic effects coupled with availability of this compound through internet sources [37] , [53] , [54] , [55] . A set of twin infants had life-threatening methemoglobinemia from food contaminated with nitrates in a case investigated by public health authorities; both infants were treated with methylene blue [46] .…”

“…However, in clinical practice, methemoglobinemia is more commonly the result of exposure to one or more exogenous substances [1] , [10] . Many causal substances have been identified, including benzocaine and other topical anesthetics [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , dapsone (anti-infective used for treatment of leprosy, dermatitis herpetiformis, and Pneumocystis jirovecii ) [10] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , antimalarial agents (e.g., chloroquine) [1] , [24] , nitric oxide [30] , [31] , and nitrites [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] ( Table 1 ). Dietary nitrates and nitrites in food and drinking water is a major cause of methemoglobinemia in some parts of the world [10] , [33] , [40] , [41] .…”

Suicide of an adolescent girl with sodium nitrite ordered on the internet

“…Fatal cases of voluntary intoxication via the use of suicide kits have recently been reported in the literature [1, 3–11].…”

Sodium nitrite suicide and social media influence

“…9 Case reports from the US, Japan, and Korea have also confirmed that sodium nitrite is being ingested as a means of suicide. [19][20][21][22][23][24][25] In 2022, researchers surveyed this literature for cases of sodium nitrite ingestion. 11 Their review identified 132 cases, 53 of which were for suicidal purposes.…”