Metahemoglobinemia y hemólisis intravascular aguda después de una intoxicación por naftaleno en un paciente pediátrico / Methemoglobinemia and acute intravascular hemolysis after naphthalene poisoning in a pediatric patient

La intoxicación por naftaleno es poco frecuente en los niños. Es causada por la ingesta, la inhalación o el contacto con la piel de sustancias que contienen naftaleno. Los pacientes suelen tener orina de color marrón oscuro, diarrea acuosa y vómito bilioso. Los signos incluyen fiebre, taquicardia, hipotensión y valores bajos en la oximetría de pulso, incluso con oxigenoterapia. Los análisis de sangre detectan anemia hemolítica, metahemoglobinemia, insuficiencia renal e hiperbilirrubinemia. Además del tratamiento sintomático, se hacen transfusiones de eritrocitos y se les administran ácido ascórbico, azul de metileno y N-acetilcisteína. En este artículo, presentamos el caso de un paciente masculino de 23 meses de edad con metahemoglobinemia y hemólisis intravascular aguda que recibió atención en la unidad de cuidados intensivos durante cinco días por intoxicación por naftaleno. Si bien la intoxicación por naftaleno es muy poco frecuente, tiene consecuencias mortales y se debe ejercer precaución con su uso y venta.

Poisoning by naphthalene is uncommon in children. It is a type of poisoning brought on by ingesting, inhaling, or coming into touch with naphthalene-containing substances on the skin. Patients typically present with an initial onset of dark brown urine, watery diarrhea, and bile vomit. The signs include fever, tachycardia, hypotension, and low pulse oximetry readings even with oxygen support. Hemolytic anemia, methemoglobinemia, renal failure, and hyperbilirubinemia are all detected in blood tests. Erythrocyte transfusion, ascorbic acid, methylene blue, and N-acetylcysteine (NAC) therapies are provided to inpatients in addition to symptomatic treatment. We present a 23-month-old male patient who developed methemoglobinemia and acute intravascular hemolysis, who was followed up in the intensive care unit for five days due to naphthalene intoxication. Although naphthalene poisoning is very rare, it should be known that it has fatal consequences, and more care should be taken in its use and sale.

Causa inusual de cianosis en el recién nacido: hemoglobina M / Unusual cause of cyanosis in the newborn: hemoglobin M

Resumen La hemoglobina M es un desorden hereditario infrecuente, causante de metahemoglobinemia y, por ende, cianosis. Las manifestaciones clínicas de esta enfermedad son amplias y variadas, por lo que se debe considerar como diagnóstico diferencial en un recién nacido con cianosis sin otra causa aparente. A continuación, se presenta el caso de un recién nacido de 5 horas de vida con cianosis generalizada desde el nacimiento y con saturaciones de oxígeno de entre 60-70%, en el que se descartaron patologías como hipoxia perinatal, patología pulmonar o cardíaca y sepsis y se documentó un nivel de metahemoglobina elevado, reportado en 21,6%, con lo cual se estableció el diagnóstico de metahemoglobinemia. El tratamiento administrado fueron dos dosis de azul de metileno, pero no hubo respuesta clínica. Por este motivo, se realizó electroforesis de hemoglobina, la cual fue compatible con hemoglobina M (Iwate o Kankakee), lo que se confirma su causa congénita de metahemoglobinemia.

Abstract Hemoglobin M is a rare hereditary disorder that causes ethemoglobinemia and therefore cyanosis. The clinical manifestations of this condition differs considerably, so it should be considered as a differential diagnosis in a newborn with cyanosis, with no other apparent cause. The case of a 5 hours old newborn is presented below, with generalized cyanosis from birth with oxygen saturations between 60-70%, in whom, upon ruling out pathologies such as perinatal hypoxia, pulmonary disease, heart disease and sepsis, a high level of methemoglobin is documented, reported in 21,6%; the diagnosis of methemoglobinemia was established. The treatment administered was two doses of methylene blue with no response. For this reason, hemoglobin electrophoresis was performed, which was compatible with Hemoglobin M (Iwate or Kankakee), confirming its congenital cause.

Sulfohemoglobinemia secundaria a zopiclona. Casos clínicos / Sulfhemoglobinemia secondary to the use of zopiclone. Report of two cases

Sulfhemoglobin (SulfHb) is formed by hemoglobin (Hb) oxidation by sulfur compounds. Sulfhemoglobinemia is mainly associated with drugs or intestinal bacterial overgrowth. Patients present with central cyanosis, an abnormal pulse oximetry and normal arterial oxygen partial pressure. These features are shared with methemoglobinemia (MetHb) whose diagnosis requires an arterial co-oximetry. Depending on the device used, SulfHb may produce interference with this technique. We report two females aged 31 and 43 years, consulting at the emergency room with cyanosis. Both had a history of acute and chronic, high dose zopiclone ingestion. Pulse oximetry showed desaturation but with normal arterial oxygen partial pressure. Cardiac and pulmonary diseases were ruled out. Co-oximetry in two different analyzers showed interference or normal MetHb percentages. No other complications ensued, and cyanosis decreased over days. Since MetHb was discarded among other causes of cyanosis in a compatible clinical context, the diagnosis of sulfhemoglobinemia was made. The confirmatory method is not available in Chile. The presence of SulfHb is difficult to diagnose, confirmatory tests are not readily available, and it frequently interferes with arterial co-oximetry. This is attributed to a similar absorbance peak of both pigments in arterial blood. Venous co-oximetry can be useful in this context. SulfHb is a self-limited condition in most cases, however it must be differentiated from methemoglobinemia to avoid inappropriate treatments like methylene blue.

Metahemoglobinemia, una entidad de diagnóstico complejo. Reporte de un caso

Methemoglobinemia is a rare condition with serious consequences if not diagnosed. We report the case of a 64-year-old woman with a history of allergy to sulfa drugs and a recent diagnosis of a small vessel vasculitis (ANCA-p) who started induction therapy with corticosteroids and rituximab. Due to the need for infectious prophylaxis, and considering her history, dapsone was administered instead of cotrimoxazole after ruling out glucose-6-phosphate dehydrogenase deficiency. During the admission to the hospital for her second dose of rituximab, and while being asymptomatic, she persistently presented a pulse oximetry ≪ 90% despite the administration of O2. Therefore, the infusion was postponed to study the patient. The arterial gasometric study by direct potentiometry revealed an O2 saturation of 98%, with a saturation gap > 5%. Considering the use of dapsone, a methemoglobinemia was suspected and confirmed by co-oximetry (methemoglobinemia 9%). Dapsone was suspended and one week later, her methemoglobinemia was absent.

Metahemoglobinemia secundaria a inhalación de "poppers": caso clínico y revisión de la literatura / Methemoglobinemia secondary to amyl nitrite inhalation. A case report and literature review

El nitrito de amilo, conocida como "poppers", se ha masificado como droga recreacional en parte por sus efectos con objetivos sexuales. Su consumo se asocia a complicaciones psiquiátricas y médicas. Reportamos el caso de un paciente que se presenta con metahemog-lobinemia moderada secundaria a la inhalación de nitrito de amilo asociado a alcohol. Al ingreso presenta cianosis peribucal y en extremidades, disociación entre oximetría de pulso y presión parcial de oxígeno en gases arteriales, además de metahemoglobinemia 29,9%. Se descartan otras intoxicaciones y causas primarias de metahemoglobinemia. Se maneja con oxigenoterapia, hidratación y ácido ascórbico, presentando una evolución favorable. Presentamos el primer caso en Chile de metahemoglobinemia secundaria al consumo de nitrito de amilo con fines recreativos.

Amyl nitrite, known as "poppers", has become popular as a recreational drug for sexual purposes. Its consumption is associated with psychiatric and medical complications. We report the case of a patient presenting with moderate methemoglobinemia secondary to amyl nitrite inhalation associated with alcohol. At admission, perioral and extremities cyanosis, a dissociation between pulse oximetry and partial pressure of oxygen in arterial gases, and methemoglobinemia 29.9% were present. Other intoxications and primary causes of methemoglobinemia were ruled out. The patient receives oxygen therapy, hydration, and ascorbic acid, presenting a favorable evolution. We report the first Chilean's case of methemoglobinemia secondary to amyl nitrite consumption for recreational purposes

Role of ascorbic acid in dapsone induced methemoglobinemia

No abstract available.

Metahemoglobinemia inducida por dapsona: presentación de un caso pediátrico / Methemoglobinemia due to Dapsone: a pediatric case report

La metahemoglobinemia es una patología caracterizada por la presencia de altas concentraciones de metahemoglobina en sangre. Esta es una forma oxidada de la hemoglobina, muy afín al oxígeno, que es incapaz de cederlo a los tejidos. Es una entidad poco frecuente, con baja sospecha diagnóstica. Aunque puede ser congénita en recién nacidos con cianosis, es más frecuente la adquirida por fármacos y tóxicos. En la Argentina, no se conoce la incidencia real de esta patología. El objetivo es comunicar un caso de metahemoglobinemia en una paciente pediátrica que ingresó al Hospital Magdalena V. de Martínez con cianosis en la cara y las extremidades, en mal estado general, con el antecedente de ingesta de varios comprimidos de dapsona, y se constató concentración sérica de metahemoglobina del 35%. El tratamiento consistió en la administración endovenosa de azul de metileno. Su evolución fue favorable.

Methemoglobinemia is a condition characterized by a high blood concentration of methemoglobin. Methemoglobinemia is a disorder that occurs when hemoglobin in the blood is oxidized to form methemoglobin, rendering it unable to transport oxygen. Although it can be congenital in cyanotic newborn, it is more often an adverse medication effect. The aim is to report a pediatric methemoglobinemia case, assisted in Magdalena V. de Martínez Hospital, with cyanosis in face and limb, in poor condition, that consumed dapsone accidentally. Her methemoglobin concentration was 35%. Intravenous methylene blue was administered with favorable outcome.

Cianosis en un paciente de 14 años: Presentación de un caso de metahemoglobinemia / Cyanosis in 14-year-old patient: Methemoglobinemia: case report

La cianosis es la coloración azulada de la piel y las mucosas debida al aumento de la concentración de hemoglobina reducida en los capilares o a la presencia de metahemoglobina en concentraciones mayores de las normales. Es importante pensar en metahemoglobinemia como diagnóstico diferencial frente a un paciente con cianosis que no responde a la administración de oxígeno cuando no existen causas cardiorrespiratorias que la justifiquen, dado que requiere de otros métodos diagnósticos y de tratamiento específico. Se presenta el caso de un paciente adolescente de 14 años de edad con cianosis secundaria a metahemoglobinemia de probable etiología congénita. Se discuten las causas, forma de presentación, diagnóstico y tratamiento.

The bluish coloration of skin and mucous membranes, called as cyanosis, could be explained by high reduced hemoglobin in the capillaries, or the presence of elevated methemoglobin concentration. It is important to think of methemoglobinemia as a differential diagnosis in a cyanotic patient who does not respond to oxygen administration once cardiorespiratory causes are discarded; since it requires other diagnostic methods and specific treatment. We described a case of cyanosis in a fourteen-year-old adolescent with probable congenital methemoglobinemia. We discussed their probable causes, clinic presentation, diagnosis and treatment.

Therapeutic effect of ascorbic acid on dapsone-induced methemoglobinemia in rats

OBJECTIVE: Dapsone (diaminodiphenyl sulfone, DDS) is currently used to treat leprosy, malaria, dermatitis herpetiformis, and other diseases. It is also used to treat pneumocystis pneumonia and Toxoplasma gondii infection in HIV-positive patients. The most common adverse effect of DDS is methemoglobinemia from oxidative stress. Ascorbic acid is an antioxidant and reducing agent that scavenges the free radicals produced by oxidative stress. The present study aimed to investigate the effect of ascorbic acid in the treatment of DDS induced methemoglobinemia. METHODS: Male Sprague-Dawley rats were divided into three groups: an ascorbic acid group, a methylene blue (MB) group, and a control group. After DDS (40 mg/kg) treatment via oral gavage, ascorbic acid (15 mg/kg), MB (1 mg/kg), or normal saline were administered via tail vein injection. Depending on the duration of the DDS treatment, blood methemoglobin levels, as well as the nitric oxide levels and catalase activity, were measured at 60, 120, or 180 minutes after DDS administration. RESULTS: Methemoglobin concentrations in the ascorbic acid and MB groups were significantly lower compared to those in the control group across multiple time points. The plasma nitric oxide levels and catalase activity were not different among the groups or time points. CONCLUSION: Intravenous ascorbic acid administration is effective in treating DDS-induced methemoglobinemia in a murine model.

Benzocaine, Methemoglobinemia and Methylene Blue / 대한소아치과학회지

The aim of this review is to introduce about the issue of benzocaine and methemoglobinemia. Through blocking the pain during dental treatment, fear and anxiety of patients will be reduced. Thus, anesthetic agent containing benzocaine is commonly used while controlling the pain of patients during treatment. However, on May 28, 2018, the Ministry of Food and Drug Safety reported a medication safety report about restricting the use of benzocaine-containing agents in infants under 24 months and children. Also, they recommended a cautious use to adolescents and adults to prevent methemoglobinemia (MHb). This report was published due to an advice from Food and Drug Administration (FDA) on May 23, 2018. When using agents containing benzocaine, dentists must consider the probability of MHb and prepare for early diagnosis and appropriate action. Since 1930s, methylene blue is known to cure MHb patients. Therefore, the proper use of methylene blue for emergencies and diagnosis methods for early diagnosis of MHb should be familiar to dentists planning for the use of topical anesthetic agents. Dentists should be trained for emergency situation of MHb caused by the use of benzocaine.

Metahemoglobinemia relacionada con ingesta de puré de acelgas / Methemoglobinemia due to ingestion of chard puree

La metahemoglobinemia es un síndrome clínico dado por la presencia de una forma aberrante de hemoglobina, ocasionada por diversos agentes oxidantes. Se describe un caso clínico de metahemoglobinemia severa asociada a la ingesta de puré de acelgas con alto contenido en nitratos y nitritos. Paciente de un año, con antecedentes de comunicación interauricular (CIA), que presentó un cambio en coloración de la piel 7 h antes, en forma progresiva, acompañado de vómitos. Ingresó al Departamento de Emergencia con cianosis generalizada que no mejoró con oxigenoterapia, taquicardia y tendencia a hipotensión arterial. En cuidados intensivos se realizó ecocardiograma que evidenció CIA sin repercusión hemodinámica. Metahemoglobinemia 37%. Se realizó dosis de azul de metileno al 1% por vía intravenosa, con franca mejoría clínica a la hora de la administración del antídoto y descenso de niveles de metahemoglobina. Alta médica a las 36 horas del ingreso. Existía una relación cronológica entre la exposición a nitratos por ingesta de un puré de acelgas y la aparición del cuadro. Los niveles de nitratos hallados en dicho alimento fueron muy elevados considerando estándares internacionales, lo que sumado a una inadecuada conservación del alimento cocido los días previos, permitió confirmar el planteo etiológico realizado. Resulta importante sospechar esta entidad patológica poco frecuente frente a cianosis que no mejora con oxígeno, y prevenir cuadros similares al descrito mediante una adecuada manipulación y conservación de las verduras con alto contenido en nitratos.

Methemoglobinemia is a clinical syndrome due to the presence of an aberrant form of hemoglobin, caused by various oxidizing agents. The study reports a case of severe methemoglobinemia associated with the ingestion of chard puree with high levels of nitrates and nitrites. A 1-year-old patient with a history of atrial septal defect (ASD), who progressively showed change of skin color 7 hours earlier, accompanied by vomiting. She was admitted to the Emergency Department with generalized cyanosis not improving with oxygen therapy, tachycardia and tendency to hypotension. In the intensive care unit, an echocardiogram showed ASD without hemodynamic complications. Methemoglobinemia 37%. A 1% methylene blue dose was administered intravenously, with clinical improvement one hour after antidote administration and decrease in methemoglobin levels. Medical discharge at 36 hours of admission. There was a chronological relationship between nitrates exposure by ingestion of chard puree and the clinical onset of methemoglobinemia. The toxic cause was confirmed after high nitrates levels were found in this vegetable considering international standards, and an inadequate preservation of the cooked chard on previous days. It is important to suspect this rare pathological entity when cyanosis fails to improve with oxygen, and to prevent poisonings similar to those described by an adequate manipulation and preservation of vegetables with high nitrate levels.

A Case of a Herbicide Poisoning Induced Methemoglobinemia Patient Treated with High-dose Vitamin C

Methemoglobinemia is a condition in which the iron portion of hemoglobin, which binds to oxygen, is oxidized to produce methemoglobin, which increases blood concentration. There are many causes of methemoglobinemia, the most common being food, drugs, and chemicals. A 75-year-old male patient who had taken an herbicide did not notice any nonspecific symptoms. However, after 4 hours, his methemoglobin levels increased to 17.1%, while after 7 hours it increased to 26.5%, at which time intravenous administration of methylene blue 1 mg/kg (an antidote) was started. After a total of five doses of methylene blue at 1 mg/kg due to reactive methemoglobinemia for about 36 hours, the methemoglobin levels increased to 23.7%. Because no more methylene blue could be administered, 10 g of ascorbic acid (vitamin C) was administered intravenously. After 82 hours, ascorbic acid 10 g was administered six times for repeated reactive methemoglobinemia. No additional reactive methemoglobinemia was observed. The ventilator and endotracheal tube were successfully removed on day 5 after admission.

A Case of Methemoglobinemia Caused by Primaquine / 대한내과학회지

Primaquine is often administered for the hypnozoite stage of Plasmodium vivax and Plasmodium ovale. Primaquine (with clindamycin) is also an alternative drug for treatment of pneumocystis pneumonia when trimethoprim/sulfamethoxazole cannot be used. Primaquine may cause methemoglobinemia, an altered state of hemoglobin in which the ferrous state of heme is oxidized to the ferric state. We report a case of methemoglobinemia caused by a standard dose of primaquine plus clindamycin in a 27-year-old female recipient of a kidney transplant who was diagnosed with pneumocystis pneumonia.

Congenital methemoglobinemia

@#This report a case of a ten-year-old female with progressive cyanosis and dyspnea on exertion. Clinical and laboratory work up ruled out a cardiac and pulmonary pathology warranting further investigation for possible hemoglobinopathies. Enzyme assay showed deficiency in cytochrome b5 reductase seen in patients with congenital methemoglobinemia. Ascorbic acid at 200mg daily afforded gradual improvement in cyanosis.

Metahemoglobinemia durante a utilização de óxido nítrico em criança submetida a transplante cardíaco: relato de caso / Acquired methemoglobinemia during nitric oxide utilization in a pediatric heart transplantation: case report

Paciente de 7 anos, sexo masculino, portador de miocardiopatia restritiva relacionada ao gene BAG3 e histórico de hipertensão pulmonar com insuficiência tricúspede importante, admitido para avalição de transplante cardíaco. Após a cirurgia deu entrada na UTI estável mas evoluiu no 1º PO com acidose metabólica, choque refratário ao volume e hipoxemia refratária a manobras de fisioterapia. Os níveis de metahemoglobina foram dosados e o óxido nítrico foi imediatamente suspenso. Iniciou-se administração endovenosa de azul de metileno na dose 3mg/kg com melhora progressiva do quadro clínico. Os níveis de metahemoglobina eram 29,05 e 5,2 ao início e final da administração da droga, respectivamente. Conclusão: Metahemoglobinemia deve ser suspeitada em pacientes que utilizam NO. Níveis elevados de metahemoglobina no sangue podem ser incompatíveis com a vida. O tratamento deve ser instituído de forma rápida e eficaz.

A 7-year-old boy was admitted for evaluation to heart transplantation with a restrictive cardiopathy congenital associated to BAG3 gene. During childhood, he developed high pulmonary hipertension with a significant tricuspid insufficiency. At first post-operative, patient has evoluted with metabolic acidosis, shock refractory to volume and refractory hypoxemia presented at maneuvers physiotherapy. The levels of methemoglobin were checked on laboratory and the nitric oxide was immediately suspended. It started the administration of methylene blue in 3 mg/kg with progressive improvement of clinical situation. Levels of metheboglobin were 29,05 before the treatment and 5,2 after methylene blue administration. Conclusion: Metahemoglobinemia must be suspected in patients using NO. Elevated levels of metahemoglobin may be incompatible with life. Treatment should be instituted quickly and effectively.

Exanguinotransfusión como tratamiento de metahemoglobinemia secundaria a dapsona. reporte de caso / Exchange transfusion to treat dapsone-induced methemoglobinemia. a case report

La dapsona es una sulfona utilizada en una variedad de enfermedades dermatológicas que incluye el pénfigo, lametahemoglobinemia es un síndrome clínico potencialmente mortal debido a la disminución del aporte de oxígenodesde la sangre hacia los tejidos; la metahemoglobinemia adquirida es la forma más frecuente y es un conocidoefecto adverso del uso de dapsona. Describimos el caso de un varón con pénfigo foliáceo y tratamiento reciente condapsona, que presentó cianosis, disnea y choque circulatorio ante concentraciones elevadas de metahemoglobina(21%); el tratamiento inicial incluyó oxigenoterapia, soporte ventilatorio invasivo, hemodinámico y administraciónde azul de metileno intravenoso, ante la ausencia de respuesta clínica se realizó exanguinotransfusión como terapiade segunda línea con respuesta óptima, el nivel sérico de metahemoglobina fue 2,3% tres horas posteriores alrecambio sanguíneo.

Dapsone is a sulphone used for a variety of dermatologic conditions including pemphigus. Methemoglobinemia isa potentially lethal syndrome due to a diminished supply of oxygen from blood to tissues, the acquired form is themost frequent presentation and it is a recognized adverse effect of dapsone. We report the case of a male patientwith pemphigus treated with dapsone that developed cyanosis, dyspnea and shock in the presence of elevatedconcentrations of methemoglobin (21%). Initial treatment included oxygen, invasive ventilatory support andintravenous administration of methylene blue, but due to lack of response, exchange transfusion was performedwith optimal response, serum level of methemoglobin after the procedure was 2.3%.

Metahemoglobinemia adquirida inducida por fármacos antipalúdicos / Acquired methemoglobinemia induced by antymalaric drugs

Clásicamente se describe cianosis como niveles de hemoglobina desoxigenada en sangre periférica por encima de 5g/dl; sin embargo se ha dejado a un lado, que dicha expresión clínica no sólo responde a esta condición, sino también a la acumulación distal de pigmentos anómalos producto de la alteración en la morfología habitual de la molécula de hemglobina o el estado químico de ésta. Por tal motivo, se presenta un interesante caso clínico en paciente masculino de 35 años de edad, quien consulta por cuadro febril agudo y diagnóstico de Paludismo por Plasmodium vivax, iniciando tratamiento antipalúdico. Posteriormente presenta, en ausencia de fiebre, cianosis peribucal y acral acompañada de disminución de la saturación a 83% por oximetría de pulso. El diagnóstico se basó en la evidencia clínica y la oximetría de pulso, el manejo terapéutico consistió en la administración de oxígeno húmedo y bolos de azul de metileno, notando franca mejoría clínica(AU)

Methemoglobinemia has traditionally been described in multiple studies. Cyanosis, and deoxygenated hemoglobin levels in peripheral blood above 5g / dL, not only responds to this condition, but also to the distal accumulation of anomalous pigments as products of an alteration in the normal morphology of the haemoglobin molecule or chemical state of this. An interesting case report is presented in a male, who after the diagnosis of Plasmodium Vivax Malaria and malaria treatment presenteded perioral the and distal cyanosis, as well as desaturation of 83% by oximetry. The diagnosis was based on clinical evidence and pulse oximetry, and therapeutic approach was based on the administration of wet oxygen and methylene blue bowling, showing marked clinical improvement(AU)

De novo alpha 2 hemoglobin gene (HBA2) mutation in a child with hemoglobin M Iwate and symptomatic methemoglobinemia since birth

Cyanosis in an apparently healthy newborn baby may be caused by hemoglobin variants associated with the formation of methemoglobin, collectively known as M hemoglobins. They should not be confused with genetic alterations in methemoglobin reductase enzyme systems of red cells since treatment and prognosis are completely different. A newborn male child was noted to be significantly cyanotic at birth and is the basis for this report. Hemoglobin isoelectric focusing, acid and alkaline gel electrophoresis, and HBA/HBB gene sequencing were performed for the child, both parents and a sister. The newborn child was treated with methylene blue in an intensive care unit fearing that he had a defective reductase system and exposure to oxidant drugs or toxins. Newborn hemoglobin screening with high performance liquid chromatography was abnormal on the 10th and 45th days but no conclusive diagnosis was reached. Cyanosis persisted up to four years of age with no other symptoms. Hemoglobin M Iwate [alpha2 87(F8) His>Tyr, HBA2:c.262C>T] was detected. It was not present in the child's presumed mother, father, sister, and brother. The analysis of 15 short tandem repeats in the trio demonstrated a de novo mutation occurrence (p-value < 1 × 10 -8). The family was reassured that no further action was necessary and genetic counseling was provided. Methemoglobins should be considered for differential diagnosis of cyanosis in newborns even if no familial cases are detected. Except for cosmetic consequences, the clinical course of patients with hemoglobin M Iwate is unremarkable.

High-dose Vitamin C therapy in Methemoglobinemia

Methylene blue is the first choice antidote for management of methemoglobinemia, however, some patients are refractory to methylene blue and in most cases, methylene blue cannot be available instantly in Korean emergency departments because of import suspension. A 69-year-old woman visited our emergency department for tachypnea and cyanosis after ingesting 30 tablets of dapsone. Because methylene blue was not available, we intravenously administrated 10 g of vitamin C for symptomatic methemoglobinemia. Repeated i.v. administrations of 10 g of vitamin C in patient without preexisting renal insufficiency successfully treated dapsone-induced methemoglobinemia without causing renal complications. Thus, we recommend that if methylene blue is unavailable or methemoglobinemia is refractory to methylene blue, repeated administrations of 10 g of vitamin C may be considered for the treatment of methemoglobinemia in patients without renal insufficiency.

A Case of Primaquine-Induced Acute Liver Failure / 대한내과학회지

Primaquine was approved for treatment of malaria in 1952 by the United States Food and Drug Administration (FDA). It has remained the only FDA-licensed drug capable of clearing the intra-hepatic schizonts and hypnozoites of Plasmodium vivax. It is associated with serious hazards and side effects, such as hemolytic anemia and methemoglobinemia. However, there is no report of primaquine causing liver injury in Korea. We describe a case of acute liver failure following primaquine overdose in a 19-year-old man.