Risk for Toxicity in Acetaminophen

Question: What organ is most at risk for toxicity in acetaminophen overdose? Answer: Acetaminophen is a common drug used as a pain killer (analgesic) and also to reduce fever (antipyretic) and is effective when delivered in proper doses. An overdose of this drug can affect the liver and is responsible for hepatotoxicity, and can cause liver failure resulting in transplantation. Metabolism of acetaminophen occurs in the liver. Usually in cases of overdose of this drug, there are no symptoms initially. Thus to identify a case of overdose, the time and quantity of the ingested drug should be determined by the physician. What chemistry laboratory values would be most useful to confirm this potential organ damage? The minimal dosage for a single consumption which endangers hepatotoxicity is 7.5 10g in adults, and 150 mg/kg in children. The general course of toxicity of acetaminophen is subdivided into 4 stages: Stage 1- hour to 1 day after consumption patients generally do not exhibit any symptoms, or may report, vomiting and nausea. Physical symptoms may include paleness, sweating and fatigue. Stage 2 3 days after consumption it is usually characterized by abdominal pain and nausea. Patients may also develop abnormal pulse rate and reduce urine output Stage 3 3-4days- after consumption - Jaundice, hypoglycemia might be observed as a consequence of hepatic necrosis. In critical cases kidney failure might also occur. Extreme cases might result in death of the person. Stage 4 4 days to 3 week after consumption- Surviving patients from stage 3, might have a complete cure. The patients acetaminophen level was 265 à ¯Ã‚ Ã‚ ­g/mL.Is she at risk for developing hepatic necrosis? As mentioned earlier the critical dosage of acetaminophen is 7.5 10 g in adults. Calculating the dosage consumed by the patient, that is 12.5 g, it poses a risk for hepatotoxicity. The given table below provides a summary of the results and their relative effects. Acetaminophen level Interpreted results 10-20 mcg/mL Therapeutic levels 150 mcg/mL 4 hrs after consumption Low risk of liver damage 200 mcg/mL 4 hours after consumption Or 50 mcg/mL 12 hours after consumption Acetaminophen toxicity and extreme liver damage Source: ("Focus On: Acetaminophen Toxicity and Treatment // ACEP", 2016) What specific antidotal therapy should be administered? What is the most crucial time period for administration? Amino acids and pseudo amino acids as methionine and N-acetyl cysteine is believed to minimize the toxicity of acetaminophen, by inhibiting its bioactivation to NAPQI or by enabling the synthesis of glutathione ("Antidotes for Poisoning by Paracetamol", 2016). Intravenous solution of N acetyl cysteine is administered in patients after 15 hours of acetaminophen overdose, who have concentration of acetaminophen in blood, above the critical level. Studies also reveal that administering an oral or intravenous solution of N-acetyl cysteine after 24 hours of acetaminophen toxicity may also be effective. The usual dosage is 300 mg/kg given for 20 hours at regular intervals, and prevents dysfunction of the liver. How is acetaminophen measured in the laboratory? Acetaminophen test is utilized to gauge the level of medication in the blood to set up a determination of overdosage, to examine the danger of liver harm, and to settle on the requirement for treatment. Brief analysis and treatment are vital for a positive result. Doctors might recommend for an acetaminophen test after 4 hours of ingestion and usually order for urine drug screen and serum salicylate levels in blood. There are numerous other test, for example, measuring the level of lactate and metabolic panel tests with creatinine. Give one proprietary name of this drug. Proprietary name of drug containing acetaminophen is Anacin. If the half life of the drug is 5 hours, how many hours would it take to achieve steady state if the drug was taken for therapeutic purposes? The time to achieve steady state would be 10 -20 hours, considering the half life of the drug is 5 hours. To what class of drugs does acetaminophen belong? Name one other drug in this class. Acetaminophen or Paracetamol belong to the analgesic and antipyretic classes of drugs. Opioids and Flupirtine are other types of analgesics, while other types of anti-pyretics include ibuprofen and naxoprene. Aspirin on the other hand is both an analgesic and antipyretic. What are the two main therapeutic actions of acetaminophen? Acetaminophen is antipyretic and analgesic in nature, but has weak affect on inflammation. It decreases the levels of the metabolites of prostaglandins in urine of humans. It is believed to reduce pain and minimize fever if ingested in a proper dose. It is effective on backaches, tooth aches, fever, arthritis and cold. References Acetaminophen Pathway (therapeutic doses), Pharmacokinetics. (2016).PharmGKB. Retrieved 11 June 2016, from https://www.pharmgkb.org/pathway/PA165986279 Focus On: Acetaminophen Toxicity and Treatment // ACEP. (2016).Acep.org. Retrieved 11 June 2016, from https://www.acep.org/Clinical---Practice-Management/Focus-On--Acetaminophen-Toxicity-and-Treatment