Acetylcysteine Inhalation Solution 20% Inhalent or Oral Administration (Acetaminophen Antidote) (RX)Acetylcysteine Solution 20% for Inhalation (Acetaminophen Antidote) is a medication used to treat cases of acetaminophen overdose. Acetaminophen (also known as paracetamol) is a common over the counter pain reliever and fever reducer, but in high doses, it can cause liver damage and even liver failure. Acetylcysteine is a potent antioxidant that helps prevent or reduce liver damage caused by an acetaminophen overdose. The solution is typically inhaled