Why does Aspirin (acetylsalicylic acid) cause Reye's syndrome?

From the Guidelines

Aspirin causes Reye's syndrome because it affects how the body processes fatty acids during viral infections, particularly in children and teenagers, as supported by the most recent evidence from 2017 1. When aspirin (acetylsalicylic acid) is given to children with viral illnesses like influenza or chickenpox, it can disrupt mitochondrial function in liver cells and inhibit beta-oxidation of fatty acids. This leads to accumulation of fat in the liver and increased ammonia levels in the blood, causing brain swelling and potentially fatal damage to both the liver and brain. The exact mechanism isn't fully understood, but aspirin appears to enhance the toxic effects of viral infections on mitochondria. Some key points to consider include:

• The risk of Reye's syndrome is associated with the use of salicylates, such as aspirin, during active infection with varicella or influenza 1.
• The low-dose therapy used for antiplatelet effect has not been associated with the development of Reye's syndrome 1.
• Children who are taking salicylates long-term should receive an annual influenza vaccine, and alternative antiplatelet medications should be considered during the 6-week period after varicella vaccine administration 1.
• Medical professionals strongly advise against giving aspirin to children and teenagers with fevers or viral illnesses, and instead recommend using acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) for fever and pain in young patients. The risk of Reye's syndrome has dramatically decreased since the 1980s when public health warnings about aspirin use in children became widespread, highlighting the importance of evidence-based recommendations in clinical practice 1.

From the FDA Drug Label

Children and teenagers who have or are recovering from chicken pox or flu-like symptoms should not use this product, if changes in behavior with nausea and vomiting occur, consult a doctor because these symptoms could be an early sign of Reyes syndrome, a rare but serious illness The FDA drug label does not answer the question.

From the Research

Aspirin and Reye's Syndrome

• Aspirin has been linked to Reye's syndrome, a rare but severe and often fatal disease, particularly in children and teenagers under 18 years of age 2.
• The exact mechanism of how aspirin causes Reye's syndrome is not fully understood, but it is believed to act as a co-factor in susceptible individuals, potentially impairing mitochondrial metabolism 2, 3.
• The use of aspirin in children with viral illnesses has been associated with the development of Reye's syndrome, leading to a decline in its use in the United States 4.

Biochemical Explanation

• Reye's syndrome is characterized by a generalized disturbance in mitochondrial metabolism, resulting in metabolic failure in the liver and other tissues 3.
• The biochemical explanation for Reye-like symptoms involves a disturbance in mitochondrial metabolism, which can be triggered by various factors, including viral infections and the use of certain medications like aspirin 3, 2.

Risk Factors and Prevention

• The risk of Reye's syndrome can be reduced by avoiding the use of aspirin in children with viral illnesses and instead using alternative antipyretic medications like acetaminophen 4, 5.
• Government health warnings and education campaigns have contributed to a decline in the incidence of Reye's syndrome, highlighting the importance of informed decision-making and responsible medication use 2, 6.
• Parents and healthcare providers should be aware of the potential risks associated with aspirin use in children and take steps to prevent Reye's syndrome, including monitoring for symptoms and seeking medical attention if necessary 6.