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

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*

OBJECTIVEThe level of blood hemoglobin and the anemia status of Chinese urban residents in 2010-2012 was analyzed.

METHODSAll the data in this study came from the China Nutrition and Health Survey in 2010-2012. By using multi-stage stratified sampling and population proportional stratified random sampling method, 74 276 residents aged above 6 from 34 metropolis and 41 middle-sized and small cities were included in this study. The concentration of blood hemoglobin was determined by cyanmethemoglobin method. Anemia was judged by the anemia standard recommended by WHO, combined with elevation correction standard. The level of blood hemoglobin, the prevalence of anemia and the 95%CI value were analyzed by using the complex sampling weighted processing, combined with the population figures released by the National Bureau of Statistics in 2009.

RESULTSIn 2010-2012, the level of blood hemoglobin of Chinese city population was(144.16 ± 0.78)g/L, (152.88 ± 0.94)g/L for male and(135.01 ± 0.71)g/L for female, while (145.65 ± 1.22)g/L for metropolis and (143.90 ± 0.89)g/L for small and medium-sized. The anemia prevalence of Chinese city population (pregnant women were not included) was 9.7%(95%CI: 9.4%-10.1%), 6.8%(95%CI: 6.4%-7.3%) for male and 12.8%(95%CI: 12.2%-13.4%) for female, while 8.5%(95% CI: 8.0%-9.0%) for metropolis and 10.0%(95%CI: 9.5%-10.4%) for small and medium-sized. The anemia prevalence of 18-44 women (15.4%, 95%CI: 14.3%-16.6%) was the highest among all the age-groups, and the average anemia prevalence of people more than 60 years-old (including) (12.5%, 95%CI: 11.8%-13.2%) was higher than the other age-groups.

CONCLUSIONThe anemia prevalence of Chinese city population in 2010-2012 was obviously decreased in comparison of 10 years ago, while, more attention and improvement measures should be take upon women at reproductive age and the elder people.

Adolescent ; Adult ; Anemia ; epidemiology ; China ; epidemiology ; Cities ; Female ; Health Surveys ; Hemoglobins ; analysis ; Humans ; Male ; Methemoglobin ; analogs & derivatives ; analysis ; Middle Aged ; Nutritional Status ; Prevalence ; Urban Population ; 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

Methemoglobinemia results from the oxidation of ferrous iron (Fe++) to ferric iron (Fe+++) within hemoglobin. It is caused by various etiologies, including the herbicide Propanil. Patients with low levels of methemoglobin (metHb) are asymptomatic but symptomatic patients and patients with high levels of metHb require treatment. Methylene blue is the first choice for the treatment of methemoblobinemia, but has some complications such as hemolytic anemia and rebound methemoglobinemia. We report the case of a 91-year-old woman who died of aniline herbicides poisoning. The level of metHb in her blood was initially 20.7% and her mental status was drowsy. She was intravenously treated with methylene blue within a therapeutic range for methemoglobinemia. After treatment with methylene blue, the level of metHb decreased but later increased above 20%. Methylene blue treatment was repeatedly attempted, but the patient suffered from hemolytic anemia and rebound methemoglobinemia. The patient finally died from renal failure and cardiopulmonary collapse. We must be careful because methemoglobinemia can occur even when treated pesticides such as propranil.
Anemia, Hemolytic ; Female ; Herbicides ; Humans ; Iron ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue ; Pesticides ; Poisoning ; Propanil* ; Renal Insufficiency

The present study was aimed to investigate the influence of freeze-drying on the quality of polymerized human placenta hemoglobin (PolyPHb). The PolyPHb solution was freeze-drying under suitable conditions. Hemoglobin concentration, methemoglobin (MetHb) content, UV spectrum, Fe3 content, oxygen-carrying capacity, pH, the average molecular weight and its distribution, circular dichroism, oxygen equilibrium curve and other indicators were measured before and after freeze-drying. The appearance, residual water content, rehydration time of the lyophilized product were also evaluated. The results showed that there was no significant difference on all the indicators measured above, which indicated that freeze-drying process had no effect on the physical and chemical properties of PolyPHb, as well as on its biological activity. Therefore, the properties of PolyPHb were stable during this freeze-drying process and could be preserved after such freeze-drying process.
Blood Substitutes ; Female ; Freeze Drying ; methods ; Hemoglobins ; chemistry ; Humans ; Methemoglobin ; analysis ; Placenta ; chemistry ; Polymerization ; Pregnancy

OBJECTIVE: To report two cases of methemoglobinemia induced by inhaled nitrobenzene and dermally absorbed aniline. METHODS: We have evaluated a 37-year-old male worker exposed to nitrobenzene by inhalation while conducting maintenance job of mononitrobenzene pump and a 25-year-old male worker exposed dermally to aniline while unloading. RESULTS: The first case is a 37-year-old male exposed to nitrobenzene. His blood methemoglobin concentration level was initially 19.8%, and chest X-ray was normal. After oxygen therapy, the blood methemoglobin concentration level decreased to 2.1%, and the symptoms were alleviated. The second case is a 25-year-old male exposed dermally to aniline. His chest X-ray was normal, but blood methemoglobin concentration level reached maximally 46.8%. He was treated with methylene blue due to relatively high blood methemoglobin level. Gradually after the treatment, his methemoglobin concentration level was normalized to 0.8% and simultaneously symptoms were resolved. CONCLUSIONS: After the thorough exposure investigations and medical evaluations, we have concluded that these cases were methemoglobinemia induced by occupational exposure to nitrobenzene and aniline. We suggest that businesses which handle methemoglobinemia-causing substances control the engineering process strictly, implement periodic screening, and establish emergency patient management system.
Adult ; Commerce ; Emergencies ; Humans ; Inhalation ; Male ; Mass Screening ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue ; Occupational Exposure ; Oxygen ; Thorax

Methylene blue (MB) is an effective antidote for methemoglobinemia. MB is a basic dye, yielding a blue solution. In the human body, hemoglobin is the oxygen-carrying protein including a ferrous atom. Hemoglobin is oxidized to methemoglobin (MetHb) with the ferric atom, which cannot bind to or carry oxygen. Equilibrium between hemoglobin and MetHb is approximately 99:1. Thus a healthy man can have about 1% of methemoglobinemia. The cytochrome b5 MetHb reductase pathway plays a major role in reducing MetHb to hemoglobin. The nicotin amide adenine dinucleotide phosphate (NADPH) MetHb reductase pathway is a minor reducing system of MetHb, and it needs NADPH as a cofactor. However, to the exceeding exogenous oxidative stress, the cytochrome b5 MetHb reductase pathway is soon exhausted, and the NADPH MetHb reductase pathway can be activated 4 to 5 times by the exogenous cofactor, MB. The decision to initiate MB therapy for methemoglobinemia depends on the MetHb level and the symptoms. The indication for MB therapy in a symptomatic patient is a MetHb level >20% and in an asymptomatic patient, a MetHb level >30%. Patients with comorbidities such as anemia, heart disease, pneumonia, chronic obstructive pulmonary disease, or liver cirrhosis can be candidates for MB therapy with an even lower MetHb level. The recommended initial dose of MB is 1 to 2 mg/kg. It can be repeated every 30 minutes to 1 hour. However, the dose should not exceed 7 mg/kg. A high dose of MB may induce methemoglobinemia paradoxically and also cause hemolytic anemia. Like other antidotes, MB has its own adverse effects.
Adenine ; Anemia ; Anemia, Hemolytic ; Antidotes ; Comorbidity ; Cytochromes b5 ; Heart Diseases ; Human Body ; Humans ; Liver Cirrhosis ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue* ; NADP ; Oxidative Stress ; Oxidoreductases ; Oxygen ; Pneumonia ; Pulmonary Disease, Chronic Obstructive