pharmacopeia
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/api/v1/drug/acetylcysteine

Mechanism of action

Sourced from openFDA

Acetylcysteine has been shown to reduce the extent of liver injury following acetaminophen overdose. Acetaminophen doses of 150 mg/kg or greater have been associated with hepatotoxicity.

Indications

Sourced from openFDA
  • Acetylcysteine Injection is indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen in patients with acute ingestion or from repeated supratherapeutic ingestion (RSI). Acetylcysteine Injection is an antidote for acetaminophen overdose indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen in patients with an acute ingestion or from repeated supratherapeutic ingestion (RSI) ( 1 ).

Contraindications

Sourced from openFDA
  • Acetylcysteine is contraindicated in patients with a previous hypersensitivity reaction to acetylcysteine [see Warnings and Precautions ( 5.1 )] . Patients with a previous hypersensitivity reaction to acetylcysteine ( 4 ).contraindicated

Dosage & administration

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Pre-Treatment Assessment Following Acute Ingestion ( 2.1 ) : Obtain a plasma or serum sample to assay for acetaminophen concentration at least 4 hours after ingestion. If the time of acetaminophen ingestion is unknown: Administer a loading dose of acetylcysteine injection immediately. Obtain an acetaminophen concentration to determine need for continued treatment. If the acetaminophen concentration cannot be obtained (or is unavailable or uninterpretable) within the 8-hour time interval after acetaminophen ingestion or there is clinical evidence of acetaminophen toxicity: Administer a loading dose of acetylcysteine injection immediately and continue treatment for a total of three doses over 21 hours. If the patient presents more than 8 hours after ingestion and the time of acute acetaminophen ingestion is known: Administer a loading dose of acetylcysteine injection immediately. Obtain acetaminophen concentration to determine need for continued treatment. If the patient presents less than 8 hours after ingestion and the time of acute acetaminophen ingestion is known and the acetaminophen concentration is known: Use the Rumack-Matthew nomogram ( Figure 1 ) to determine whether or not to initiate treatment with acetylcysteine injection ( 2.2 ). Nomogram for Estimating Potential for Hepatotoxicity from Acute Acetaminophen Ingestion ( 2.2 ): See Full Prescribing Information for instructions on how to use the nomogram to determine the need for dosing.

Warnings & precautions

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Hypersensitivity Reactions, Including Hypotension, Wheezing, Shortness of Breath and Bronchospasm: Observe patients during and after the infusion; immediately discontinue infusion if a serious reaction occurs and initiate appropriate treatment. Acetylcysteine infusion may be carefully restarted after treatment of hypersensitivity has been initiated ( 5.1 ). Fluid Overload: Total volume administered should be reduced for patients weighing less than 40 kg and for those requiring fluid restriction ( 5.2 ). 5.1 Hypersensitivity Reactions Serious acute hypersensitivity reactions during acetylcysteine administration including rash, hypotension, wheezing, and/or shortness of breath, have been observed in patients receiving intravenous acetylcysteine for acetaminophen overdose and occurred soon after initiation of the infusion [see Adverse Reactions ( 6.1 )] . If a severe hypersensitivity reaction occurs, immediately stop the infusion of acetylcysteine and initiate appropriate treatment. One patient with asthma developed bronchospasm and died after intravenous administration of acetylcysteine. Acetylcysteine should be used with caution in patients with asthma, or where there is a history of bronchospasm. Patients with asthma should be closely monitored during initiation of acetylcysteine therapy and throughout acetylcysteine therapy. Acute flushing and erythema of the skin may occur in patients receiving acetylcysteine intravenously.

Adverse reactions

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Most common adverse reactions (> 2%) are rash, urticaria/facial flushing and pruritus ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Sagent Pharmaceuticals, Inc. at 1-866-625-1618 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In the literature the most frequently reported adverse reactions attributed to intravenous acetylcysteine administration were rash, urticaria and pruritus. The frequency of adverse reactions has been reported to be between 0.2% and 21%, and they most commonly occur during the initial loading dose of acetylcysteine. Loading Dose/Infusion Rate Study In a randomized, open-label, multi-center clinical study conducted in Australia in patients with acetaminophen poisoning, the rates of hypersensitivity reactions between a 15-minute and 60-minute intravenous infusion for the 150 mg/kg loading dose of acetylcysteine were compared. The incidence of drug-related adverse reactions occurring within the first 2 hours following acetylcysteine administration is presented in Table 5 . Overall, 17% of patients developed an acute hypersensitivity reaction (18% in the 15-minute infusion group; 14% in the 60-minute infusion group) [see Warnings and Precautions ( 5.1 ), Clinical Studies ( 14 )] . Table 5.

Use in specific populations

Sourced from openFDA

8.1 Pregnancy Risk Summary Limited published case reports and case series of pregnant women exposed to acetylcysteine during various trimesters are not sufficient to inform any drug associated risk. Delaying treatment of acetaminophen overdose may increase the risk of maternal or fetal morbidity and mortality [see Clinical Considerations ]. Reproduction studies in rats and rabbits following oral administration of acetylcysteine during the period of organogenesis at doses similar to the total intravenous dose (based on the body surface area) did not cause any adverse effects to the fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Acetaminophen and acetylcysteine cross the placenta. Delaying treatment in pregnant women with acetaminophen overdose and potentially toxic acetaminophen plasma levels may increase the risk of maternal and fetal morbidity and mortality.

Pharmacokinetics

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Metabolism
After a single intravenous dose of acetylcysteine, the plasma concentration of total acetylcysteine declined in a poly-exponential decay manner with a mean terminal half-life (T 1/2 ) of 5.6 hours. The mean clearance (CL) for acetylcysteine was 0.11 liter/hr/kg and renal CL constituted about 30% of the total CL.

Overdosage

Sourced from openFDA

An initial 150 mg/kg dose of acetylcysteine for a patient weighing 106 kg was mistakenly calculated as 160 g (a decimal point error resulting in a 10-fold higher than prescribed dose). An hour after the infusion started, the patient complained of generalized heat sensation and body pain and developed widespread urticaria and hypotension. The second acetylcysteine infusion was withheld and the patient was treated for anaphylaxis. Despite treatment the patient succumbed to the acute inflammatory reaction and died. Single intravenous doses of acetylcysteine at 1000 mg/kg in mice, 2445 mg/kg in rats, 1500 mg/kg in guinea pigs, 1200 mg/kg in rabbits and 500 mg/kg in dogs were lethal. Symptoms of acute toxicity in the animals were ataxia, hypoactivity, labored respiration, cyanosis, loss of righting reflex and convulsions.

Approval history

Sourced from openFDA
  • Aug 30, 1994ANDAANDA074037Hospira
  • Aug 30, 1994ANDAANDA073664Hospira
  • Jul 28, 1995ANDAANDA072489Am Regent
  • Jul 28, 1995ANDAANDA072547Am Regent
  • Jan 23, 2004NDANDA021539Cumberland Pharms
  • Jun 21, 2012ANDAANDA203853Alvogen
  • Nov 7, 2012ANDAANDA200644Fresenius Kabi Usa
  • Feb 11, 2014ANDAANDA204674Alvogen

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
9,110 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Dyspnoea7608.3%
  2. 2Drug Ineffective6557.2%
  3. 3Off Label Use6517.1%
  4. 4Pneumonia6126.7%
  5. 5Pyrexia5025.5%
  6. 6Fatigue4364.8%
  7. 7Nausea4244.7%
  8. 8Diarrhoea3383.7%
  9. 9Vomiting3183.5%
  10. 10Hypertension3113.4%
  11. 11Death3093.4%
  12. 12Chronic Obstructive Pulmonary Disease3073.4%
  13. 13Cough2983.3%
  14. 14Hypotension2883.2%
  15. 15Condition Aggravated2843.1%

Literature

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Recent PubMed references pinned to Acetylcysteine as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 662 ClinicalTrials.gov registrations naming Acetylcysteine as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Acetylcysteine work?
Acetylcysteine has been shown to reduce the extent of liver injury following acetaminophen overdose. Acetaminophen doses of 150 mg/kg or greater have been associated with hepatotoxicity.
What is Acetylcysteine used for?
According to FDA labeling, Acetylcysteine carries indications including: Acetylcysteine Injection is indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen in patients with acute ingestion or from repeated supratherapeutic ingestion (RSI). Acetylcysteine Injection is an antidote for acetaminophen overdose indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen in patients with an acute ingestion or from repeated supratherapeutic ingestion (RSI) ( 1 ).. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Acetylcysteine?
Acetylcysteine is classified as Antidotes, Mucolytics, Other ophthalmologicals, Antidote, Antidote for Acetaminophen Overdose, Mucolytic, Free Radical Scavenging Activity, Reduction Activity, Decreased Respiratory Secretion Viscosity, Increased Glutathione Concentration.
What are the brand names for Acetylcysteine?
Acetylcysteine is marketed under brand names including Acetadote.
What are the contraindications for Acetylcysteine?
Acetylcysteine labeling lists contraindications including: Acetylcysteine is contraindicated in patients with a previous hypersensitivity reaction to acetylcysteine [see Warnings and Precautions ( 5.1 )] . Patients with a previous hypersensitivity reaction to acetylcysteine ( 4 ).. Always consult the full prescribing information and a clinician.
Note. Data for acetylcysteine is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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