Methaemoglobinaemia

Question 1

What is methaemoglobinaemia?

Answer 1

Methemoglobinemia (congenital or acquired) occurs when red blood cells (RBCs) contain methemoglobin at levels higher than 1%.

Methemoglobinemia can be congenital, which means you’re born with it, or acquired, which means you develop it after being exposed to certain chemicals, medications, or foods.

Question 2

How can drug or chemical induced methaemoglobinaemia be treated?

Answer 2

With methylthioninium chloride if the methaemoglobin concentration is 30% higher, or if symptoms of tissue hypoxia are present despite oxygen therapy.

Question 3

How does methylthionium chloride work in treating methaemoglobinaemia?

Answer 3

It reduces the ferric iron of methaemoglobin back to the ferrous iron of heamoglobin; however in high doses it can itself cause methaemoglobinaemia.