No abstract available.
Ascorbic Acid ; Dapsone ; Methemoglobinemia

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.
Animals ; Ascorbic Acid* ; Catalase ; Dapsone ; Dermatitis Herpetiformis ; Free Radicals ; Humans ; Leprosy ; Malaria ; Male ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue ; Nitric Oxide ; Oxidative Stress ; Plasma ; Pneumonia, Pneumocystis ; Rats* ; Rats, Sprague-Dawley ; Tail ; Toxoplasmosis ; Veins

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.
Adolescent ; Adult ; Anesthetics ; Anxiety ; Benzocaine ; Child ; Dentists ; Diagnosis ; Early Diagnosis ; Emergencies ; Humans ; Infant ; Methemoglobinemia ; Methylene Blue ; United States Food and Drug Administration

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.
Methemoglobinemia ; Cyanosis

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.
Administration, Intravenous ; Aged ; Ascorbic Acid* ; Humans ; Iron ; Male ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue ; Oxygen ; Poisoning* ; Ventilators, Mechanical ; Vitamins*

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.
Adult ; Clindamycin ; Female ; Heme ; Humans ; Kidney ; Methemoglobin ; Methemoglobinemia* ; Plasmodium ovale ; Plasmodium vivax ; Pneumonia, Pneumocystis ; Primaquine*

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.
Aged ; Ascorbic Acid* ; Cyanosis ; Dapsone ; Emergency Service, Hospital ; Female ; Humans ; Methemoglobinemia* ; Methylene Blue ; Renal Insufficiency ; Tablets ; Tachypnea

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.
Anemia, Hemolytic ; Drug-Induced Liver Injury ; Humans ; Korea ; Liver ; Liver Failure, Acute* ; Malaria ; Methemoglobinemia ; Plasmodium vivax ; Primaquine ; Schizonts ; United States Food and Drug Administration ; Young Adult

We report two cases of toxic methemoglobinemia caused by an inert ingredient in pesticide product after intentional ingestion of pesticide. First, 51-year-old male visited to the emergency department (ED) after the ingestion of pesticide in a suicide attempt. Initial methemoglobin (MetHb) level was 25.6%. We did not know the cause of methemoglobinemia at that time. Second, 56-year-old female visited to the ED after the ingestion of the same pesticide in a suicide attempt. MetHb level after 30 minutes was 16.1%. The patients were treated with methylene blue. We contacted to the Korean Rural Development Administration and estimated that magnesium nitrate was more likely to cause methemoglobinemia. This report highlights the importance of considering the possibility of methemoglobinemia caused by inert ingredient in pesticide and early antidotal therapy.
Eating* ; Emergency Service, Hospital ; Female ; Humans ; Magnesium ; Male ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue ; Middle Aged ; Pesticides ; Social Planning ; Suicide

We report two cases of toxic methemoglobinemia caused by an inert ingredient in pesticide product after intentional ingestion of pesticide. First, 51-year-old male visited to the emergency department (ED) after the ingestion of pesticide in a suicide attempt. Initial methemoglobin (MetHb) level was 25.6%. We did not know the cause of methemoglobinemia at that time. Second, 56-year-old female visited to the ED after the ingestion of the same pesticide in a suicide attempt. MetHb level after 30 minutes was 16.1%. The patients were treated with methylene blue. We contacted to the Korean Rural Development Administration and estimated that magnesium nitrate was more likely to cause methemoglobinemia. This report highlights the importance of considering the possibility of methemoglobinemia caused by inert ingredient in pesticide and early antidotal therapy.
Eating ; Emergency Service, Hospital ; Female ; Humans ; Magnesium ; Male ; Methemoglobin ; Methemoglobinemia ; Methylene Blue ; Middle Aged ; Pesticides ; Social Planning ; Suicide