Advice for healthcare professionals: the authorised posology for intravenous N-acetylcysteine (NAC) in the treatment of paracetamol overdose is 3 consecutive intravenous infusions Some studies reported that administration of NAC 63.6% and even 50% is associated with mild to life-threateningly severe side effects; these are quite prevalent when using oral treatment, and there is always a risk of iatrogenic overdose when using intravenous NAC. Introduction Acetylcysteine (NAC) is FDA approved to reduce the extent of liver injury after acetaminophen overdose. Acetadote® (acetylcysteine) was approved by the FDA If above treatment line, NAC should be initiated within 8 hours post-ingestion. Chronic acetaminophen ingestion Patients taking repeated, supratherapeutic ( 4 g/day) acetaminophen ingestions. When the NAC study was begun in 1976, the FDA required a line that was 25% below the original line now called the treatment line. The study line which is now referred to as the treatment line was created starting at 150 at 4 hours and is the usual line used in the United States to determine treatment of acetaminophen overdose. This was published in 1981. The antidotal efficacy of NAC is determined by great extent to the time that treatment is initiated after an overdose of acetaminophen. NAC therapy should be initiated within 8 hours of an acute ingestion and otherwise as soon as possible. While many protocols have defined lengths of treatment, it is generally recommended that NAC be administered until the serum acetaminophen concentration is. Acetaminophen (Tylenol) Poisoning Treatment Treatment in the emergency department depends on the condition of the person and any other medications taken. If someone is suspected of having taken an overdose but has no symptoms, the doctor may begin the following treatment: We conclude that N-acetylcysteine treatment should be started within eight hours of an acetaminophen overdose, but that treatment is still indicated at least as late as 24 hours after ingestion. A 25-year-old man presents to the emergency department with a toothache. During the evaluation, the physician determines that the patient has been taking large doses of over-the-counter acetaminophen along with an acetaminophen–hydrocodone product for the past 5 days. Correspondence from The New England Journal of Medicine — A 20-Hour Treatment for Acute Acetaminophen Overdose.