Acetaminophen

• Acetaminophen is a nonopioid analgesic used to treat mild to moderate pain and reduce fever.
• Acetaminophen offers similar benefits to COX-1 and COX-2 inhibitors.
• It does not typically cause serious adverse reactions when taken in therapeutic doses.

Expected Pharmacologic Action

• Acetaminophen is a COX inhibitor that primarily affects the CNS.
• It effectively alleviates pain and reduces fever.
• It lacks anti-inflammatory or anticoagulant effects due to limited peripheral inhibition.
• It poses a lower risk of gastric ulcers and cardiovascular events because it does not adversely affect the gastric mucosa or platelets.

Adverse Drug Reactions

• Liver damage can occur with toxic doses taken over extended periods.
• Hypertension, particularly in women, can result from daily use.

Interventions

• Monitor for early signs of overdose or poisoning, including abdominal discomfort, nausea, vomiting, diaphoresis, and diarrhea.
• Liver damage can occur 48-72 hours post overdose.
• Administer acetylcysteine orally or intravenously to reverse overdose and minimize liver injury.
• Regularly monitor blood pressure in clients, especially women, who take acetaminophen regularly.

Administration

• Can be administered orally or rectally.
• Adults and children over 12 should not exceed 4g daily.
• Base children's dosage on manufacturer guidelines related to age and weight.
• Concentrated acetaminophen drops are available for infants and administered via a dropper, typically less than 1 mL.
• Caution clients about the presence of acetaminophen in many combination products, like cold preparations, to avoid overdose.

Safety Alert

• Instruct clients about the dangers of acetaminophen toxicity.
• Over-the-counter medications can be lethal in large amounts.
• Acetaminophen is highly toxic to the liver when exceeding 4g per day.
• Combination cold medications often contain acetaminophen.
• Toxic doses can cause hepatitis and liver damage, potentially leading to liver failure.

Client Instructions

• Adults and children over 12 should not exceed 4 grams per day.
• Infants and children under 12 should adhere to the manufacturer's recommended dose based on age and weight.
• Report any abdominal discomfort, nausea, vomiting, diaphoresis, or diarrhea immediately as signs of possible overdose.
• Encourage regular blood pressure checks, especially for women.

Contraindications and Precautions

• Clients with alcohol use disorder should avoid acetaminophen due to the increased risk of liver damage.
• Use caution in clients with anemia, immune suppression, and hepatic or renal disease.

Interactions

• Alcohol increases the risk of liver injury when combined with high doses of acetaminophen.
• Concurrent use with warfarin increases bleeding risk.
• Cholestyramine reduces acetaminophen absorption.

Question Answer

• Acetylcysteine should be administered in the event of an acetaminophen overdose.