Final answer:
Inhaled drugs and substances that can cause methemoglobinemia include aromatic nitro and amino compounds, acetanilide, and sulfonamides. Methemoglobin is unable to effectively bind oxygen, and elevated levels can result in symptoms like cyanosis and dyspnoea. Methemoglobin can also be used to treat cyanide poisoning.
Step-by-step explanation:
Inhaled Drugs Causing Methemoglobinemia
Methemoglobinemia is a condition characterized by an elevated concentration of methemoglobin in the blood. Methemoglobin is a form of hemoglobin in which the iron within the heme group is in the ferric (Fe³⁺) rather than the ferrous (Fe²⁺) state, rendering it unable to bind oxygen effectively. Normally, the peroxidase action of glutathione in red blood cells prevents significant increases in methemoglobin.
Several inhaled drugs and substances can induce methemoglobinemia by oxidizing hemoglobin. These include aromatic nitro and amino compounds that are often encountered in factory settings, as well as acetanilide and sulfonamides, which are drugs taken for various health conditions. Symptoms of methemoglobinemia can include cyanosis, which is a bluish tint to the skin, and dyspnoea, or difficulty breathing.
Methemoglobin plays a crucial role in certain medical situations. For instance, it can be used to overcome cyanide poisoning by binding with cyanide to form cyanomethemoglobin, thus preventing the toxic effects of cyanide on the body.