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Dapsone-induced Methemoglobinemia in a Patient of Leprosy.

Das J, Katyal A, Naunwaar D - Indian J Dermatol (2015 Jan-Feb)

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology, 167 MH, C/O 56 APO, India.

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Sir, Methemoglobinemia is a rare possible diagnosis when patients present with cyanosis and other features of hypoxia that are unrelated to cardiopulmonary causes... Methemoglobinemia is usually symptomatic, when methemoglobin (metHb) levels are more than 15% of the total hemoglobin (Hb) value... Methemoglobinemia may be congenital or acquired... Congenital methemoglobinemia arises from mutations that stabilize iron in the ferric state (e.g., HbM Iwata or from mutations that impair the enzymes that reduce methemoglobin to hemoglobin (e.g., methemoglobin reductase, NADP diaphorase), and manifest early in life... In patients presenting with cyanosis and symptoms of hypoxia, blood oxygen level is determined by the pulse oximetry derived SO2 and the ABG derived PO2 and SO2... Clue to the diagnosis of methemoglobinemia is the presence of a saturation gap, the difference between the SO2 measured by ABG analysis and pulse oximetry... Typically, this saturation gap is greater than 5% in cases of methemoglobinemia... The CO-oximeter measures light absorbance of different wavelengths that correspond to the absorption characteristics of HHb, O2Hb, carboxyhemoglobin, and metHb; providing a more accurate measurement of SO2... Intravenous injection of methylene blue at an initial dose of 1-2 mg/kg (0.1-0.2 mL/kg of a 1% solution) is effective for emergency therapy... Milder cases and follow up of severe cases can be treated orally with methylene blue (60 mg three to four times each day) or ascorbic acid (300-600 mg/day)... Ascorbic acid decreases oxidative stress, protecting RBC from hemolysis and also reduces methemoglobin formation... As dosage of Dapsone in leprosy treatment usually does not produce significant methemoglobinemia, clinician must be aware of this adverse effect for safely using Dapsone in practice.

No MeSH data available.


Normalization of venous blood color after 2 weeks
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Figure 4: Normalization of venous blood color after 2 weeks

Mentions: A 22-year-old man presented to our hospital with complaints of exertional dyspnea, headache, and cyanosis of 3 days duration. He was on dapsone-based (100 mg OD) multi-drug therapy for Hansen's disease (borderline tuberculoid) since 6 months. He had no history of orthopnea, chest pain, palpitations, cough, syncope, weight loss, edema, hemoptysis, or exposure to chemicals. His past history was negative for heart disease, pulmonary disease, or similar complaints. The patient had central [Figure 1] and peripheral cyanosis, normal vital signs, and SO2 value of 85% by pulse oximetry. Radial artery and venous blood [Figure 2] was dark colored. Arterial blood gas (ABG) analysis revealed the following values: PH - 7.44, PCO2 - 39.8 mmHg, PO2 - 147.5 mmHg, oxygen saturation (SO2) - 99%, Hb - 15 gm/dL, H+ - 36 nmol/L, Na+ - 141 mmol/L, Ca2+ - 7.4 mmol/L, Cl− - 95 mmol/L, and HCO3 - 26.5 mmol/L. All other relevant hematological, biochemical, and radiological parameters were within normal limits. Patient was administered 100% O2 inhalation for initial 2 days, but there was no improvement in cyanosis and SO2 by pulse oximetry remained 85%. Repeat ABG revealed almost same values. He was given oral vitamin C (500 mg/day) and observed thereafter. There was a gradual increase in SO2 level with value of 90% a week later and 99% after 2 weeks. Patient was asymptomatic, no cyanosis was evident [Figure 3], and there was change in color of venous blood by this time [Figure 4]. Dapsone was discontinued since the date of hospitalization.


Dapsone-induced Methemoglobinemia in a Patient of Leprosy.

Das J, Katyal A, Naunwaar D - Indian J Dermatol (2015 Jan-Feb)

Normalization of venous blood color after 2 weeks
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4318053&req=5

Figure 4: Normalization of venous blood color after 2 weeks
Mentions: A 22-year-old man presented to our hospital with complaints of exertional dyspnea, headache, and cyanosis of 3 days duration. He was on dapsone-based (100 mg OD) multi-drug therapy for Hansen's disease (borderline tuberculoid) since 6 months. He had no history of orthopnea, chest pain, palpitations, cough, syncope, weight loss, edema, hemoptysis, or exposure to chemicals. His past history was negative for heart disease, pulmonary disease, or similar complaints. The patient had central [Figure 1] and peripheral cyanosis, normal vital signs, and SO2 value of 85% by pulse oximetry. Radial artery and venous blood [Figure 2] was dark colored. Arterial blood gas (ABG) analysis revealed the following values: PH - 7.44, PCO2 - 39.8 mmHg, PO2 - 147.5 mmHg, oxygen saturation (SO2) - 99%, Hb - 15 gm/dL, H+ - 36 nmol/L, Na+ - 141 mmol/L, Ca2+ - 7.4 mmol/L, Cl− - 95 mmol/L, and HCO3 - 26.5 mmol/L. All other relevant hematological, biochemical, and radiological parameters were within normal limits. Patient was administered 100% O2 inhalation for initial 2 days, but there was no improvement in cyanosis and SO2 by pulse oximetry remained 85%. Repeat ABG revealed almost same values. He was given oral vitamin C (500 mg/day) and observed thereafter. There was a gradual increase in SO2 level with value of 90% a week later and 99% after 2 weeks. Patient was asymptomatic, no cyanosis was evident [Figure 3], and there was change in color of venous blood by this time [Figure 4]. Dapsone was discontinued since the date of hospitalization.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology, 167 MH, C/O 56 APO, India.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Sir, Methemoglobinemia is a rare possible diagnosis when patients present with cyanosis and other features of hypoxia that are unrelated to cardiopulmonary causes... Methemoglobinemia is usually symptomatic, when methemoglobin (metHb) levels are more than 15% of the total hemoglobin (Hb) value... Methemoglobinemia may be congenital or acquired... Congenital methemoglobinemia arises from mutations that stabilize iron in the ferric state (e.g., HbM Iwata or from mutations that impair the enzymes that reduce methemoglobin to hemoglobin (e.g., methemoglobin reductase, NADP diaphorase), and manifest early in life... In patients presenting with cyanosis and symptoms of hypoxia, blood oxygen level is determined by the pulse oximetry derived SO2 and the ABG derived PO2 and SO2... Clue to the diagnosis of methemoglobinemia is the presence of a saturation gap, the difference between the SO2 measured by ABG analysis and pulse oximetry... Typically, this saturation gap is greater than 5% in cases of methemoglobinemia... The CO-oximeter measures light absorbance of different wavelengths that correspond to the absorption characteristics of HHb, O2Hb, carboxyhemoglobin, and metHb; providing a more accurate measurement of SO2... Intravenous injection of methylene blue at an initial dose of 1-2 mg/kg (0.1-0.2 mL/kg of a 1% solution) is effective for emergency therapy... Milder cases and follow up of severe cases can be treated orally with methylene blue (60 mg three to four times each day) or ascorbic acid (300-600 mg/day)... Ascorbic acid decreases oxidative stress, protecting RBC from hemolysis and also reduces methemoglobin formation... As dosage of Dapsone in leprosy treatment usually does not produce significant methemoglobinemia, clinician must be aware of this adverse effect for safely using Dapsone in practice.

No MeSH data available.