|
ACETADOTE (acetylcysteine) Injection
HIGHLIGHTS OF PRESCRIBING INFORMATION
These highlights do not include all the information needed to use ACETADOTE safely and effectively. See full prescribing information for ACETADOTE.
ACETADOTE (acetylcysteine) Injection
Initial U.S. Approval: 2004
INDICATIONS AND USAGE
Acetadote is an antidote for acetaminophen overdose indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen (1)
DOSAGE AND ADMINISTRATION
The total dose of Acetadote is 300 mg/kg given as 3 separate doses and administered over a total of 21 hrs. Please refer to the guidelines below for dose preparation based upon patient weight.
Dosing for patients who weigh 5 kg to 20 kg (2.1):
Loading Dose: 150 mg/kg diluted in 3 mL/kg of diluent* administered over 1 hr
Second Dose: 50 mg/kg diluted in 7 mL/kg of diluent* administered over 4 hrs
Third Dose: 100 mg/kg diluted in 14 mL/kg of diluent* administered over 16 hrs
Dosing for patients who weigh 21 kg to 40 kg (2.1):
Loading Dose: 150 mg/kg diluted in 100 mL of diluent* administered over 1 hr
Second Dose: 50 mg/kg diluted in 250 mL of diluent* administered over 4 hrs
Third Dose: 100 mg/kg diluted in 500 mL of diluent* administered over 16 hrs
Dosing for patients who weigh 41 kg to 100 kg (2.1):
Loading Dose: 150 mg/kg diluted in 200 mL of diluent* administered over 1 hr
Second Dose: 50 mg/kg diluted in 500mL of diluent* administered over 4 hrs
Third Dose: 100 mg/kg diluted in 1000 mL of diluent* administered over 16 hrs
*Acetadote is compatible with the following diluents; 5% Dextrose in Water, 0.45% Sodium Chloride Injection, and Sterile Water for Injection
Dosing for patients who weigh more than 100 kg (2.1):
No specific studies have been conducted to eva luate the use of or necessity of dosing adjustments in patients weighing over 100 kg. Limited information is available regarding the dosing requirements of patients that weigh more than 100 kg. The dose of Acetadote recommended in these patients should be a loading dose of 15,000 mg infused over one hour followed by a first maintenance dose of 5,000 mg over 4 hrs and a second maintenance dose of 10,000 mg over 16 hrs
DOSAGE FORMS AND STRENGTHS
Each single-dose vial contains 6 g/30 mL (200 mg/mL), Acetadote Injection (3)
CONTRAINDICATIONS
Patients with previous anaphylactoid reaction to acetylcysteine (4)
WARNINGS AND PRECAUTIONS
-
Monitor as acute flushing and erythema of the skin may occur; usually associated with the loading dose; often resolves spontaneously despite continued infusion (5.1)
-
Monitor for serious anaphylactoid reactions; infusion may be interrupted until treatment of anaphylactoid symptoms has been initiated (5.1)
-
Should be used with caution in patients with asthma, or where there is a history of bronchospasm (5.2)
-
Total volume administered should be adjusted for patients less than 40 kg and for those requiring fluid restriction (5.3)
ADVERSE REACTIONS
Most common adverse reactions (incidence greater than 2%) are rash, urticaria/facial flushing and pruritus (6.1)
To report SUSPECTED ADVERSE REACTIONS, contact Cumberland Pharmaceuticals Inc. at 1-877-484-2700 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
No drug-drug interaction studies have been conducted (7)
USE IN SPECIFIC POPULATIONS
Pregnancy: This drug should be used during pregnancy only if clearly needed (8.1)
Nursing Mothers: Unknown if drug is excreted in human milk (8.3)
Pediatric Use: See dose adjustment for patients less than 40 kg (2)
See 17 for PATIENT COUNSELING INFORMATION.
Revised: 6/2013
FULL PRESCRIBING INFORMATION: CONTENTS*
1 INDICATIONS AND USAGE
Acetadote is an antidote for acetaminophen overdose indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen. Overdose incidences are divided into two types; Acute Ingestion or Repeated Supratherapeutic Ingestion (RSI). [see Dosage and Administration (2) and Acetaminophen Assays – Interpretation and Methodology-(Acute or Repeated Supratherapeutic Ingestion) (1.1, 1.2)].
On admission for suspected acute acetaminophen overdose, a serum blood sample should be drawn at least 4 hours after ingestion to determine the acetaminophen level and will serve as a basis for determining the need for treatment with acetylcysteine. If the patient presents after 4 hours post-ingestion, the serum acetaminophen sample should be determined immediately.
Acetadote should be administered within 8 hours from acetaminophen ingestion for maximal protection against hepatic injury for patients whose serum acetaminophen levels fall above the “possible” toxicity line on the Rumack-Matthew nomogram (line connecting 150 mcg/mL at 4 hours with 37.5 mcg/mL at 12 hours); [see Acetaminophen Assays – Interpretation and Methodology (1.1, 1.2)]. If the time of ingestion is unknown, or the serum acetaminophen level is not available, cannot be interpreted, or is not available within the 8 hour time interval from acetaminophen ingestion, Acetadote should be administered immediately if 24 hours or less have elapsed from the reported time of ingestion of an overdose of acetaminophen, regardless of the quantity reported to have been ingested.
The aspartate aminotransferase (AST, SGOT), alanine aminotranferase (ALT, SGPT), bilirubin, prothrombin time, creatinine, blood urea nitrogen (BUN), blood glucose, and electrolytes also should be determined in order to monitor hepatic and renal function and electrolyte and fluid balance.
NOTE: The critical ingestion-treatment interval for maximal protection against severe hepatic injury is between 0 – 8 hours. Efficacy diminishes progressively after 8 hours and treatment initiation between 15 and 24 hours post-ingestion of acetaminophen yields limited efficacy. However, it does not appear to worsen the condition of patients and it should not be withheld, since the reported time of ingestion may not be correct.
1.1 Acetaminophen Assays Interpretation and Methodology – Acute Ingestion
The acute ingestion of acetaminophen in quantities of 150 mg/kg or greater may result in hepatic toxicity. However, the reported history of the quantity of a drug ingested as an overdose is often inaccurate and is not a reliable guide to therapy of the overdose. Therefore, plasma or serum acetaminophen concentrations, determined as early as possible, but no sooner than four hours following an acute overdose, are essential in assessing the potential risk of hepatotoxicity. If an assay for acetaminophen cannot be obtained, it is necessary to assume that the overdose is potentially toxic.
Interpretation of Acetaminophen Assays
-
When results of the plasma acetaminophen assay are available, refer to the nomogram in Figure 1 to determine if plasma concentration is in the potentially toxic range. Values above the line connecting 200 mcg/mL at 4 hours with 50 mcg/mL at 12 hours (probable line) are associated with a probability of hepatic toxicity if an antidote is not administered.
-
If the predetoxification plasma level is above the line connecting 150 mcg/mL at 4 hours with 37.5 mcg/mL at 12 hours (possible line), continue with maintenance doses of acetylcysteine. It is better to err on the safe side and thus this line, defining possible toxicity, is plotted 25% below the line defining probable toxicity.
-
If the predetoxification plasma level is below the line connecting 150 mcg/mL at 4 hours with 37.5 mcg/mL at 12 hours (possible line), there is minimal risk of hepatic toxicity, and acetylcysteine treatment may be discontinued.
Estimating Potential for Hepatotoxicity: The following depiction of the Rumack-Matthew nomogram has been developed to estimate the probability that plasma levels in relation to intervals post-ingestion will result in hepatotoxicity.
The Rumack-Matthew nomogram may underestimate the risk for hepatotoxicity in some patients with risk factors such as chronic alcoholism, malnutrition, or CYP2E1 enzyme inducing drugs (e.g., isoniazid).
Figure 1. Rumack-Matthew Nomogram
Figure 1. Michael J Hodgman, Alexander R Garrard, A Review of Acetaminophen Poisoning. Crit Care Clin. 28 (2012) 499-516.
Stephen J. Wolf, Kennon Heard, et.al, Clinical Policy: Critical Issues in the Management of Patients Presenting to the Emergency Department with Acetaminophen Overdose. Ann Emerg Med. 2007:50:292-313.
1.2 Acetaminophen Assays Interpretation and Methodology – Repeated Supratherapeutic Ingestion
Repeated Supratherapeutic Ingestion (RSI) is defined as ingestion of acetaminophen at doses higher than those recommended for extended periods of time. The nomogram does not apply to patients with RSI. Treatment is based on the acetaminophen and elevated AST/ALT levels indicative of potential toxicity due to acetaminophen. For specific treatment information regarding the clinical management of repeated supratherapeutic acetaminophen overdose, please contact your regional poison center at 1-800-222-1222, or alternatively, a special health professional assistance line for acetaminophen overdose at 1-800-525-6115.
Figure 2. Acetadote Treatment Flow Chart
1Acetaminophen levels drawn less than 4 hours post-ingestion may be misleading.
2With an extended-release preparation, an acetaminophen level drawn less than 8 hours post-ingestion may be misleading. Draw a second level at 4 to 6 hours after the initial level. If either falls above the toxicity line, acetylcysteine treatment should be initiated.
3Acetylcysteine may be withheld until acetaminophen assay results are available as long as initiation of treatment is not delayed beyond 8 hours post-ingestion. If more than 8 hours post-ingestion, start acetylcysteine treatment immediately.
2 DOSAGE AND ADMINISTRATION
The total dose of Acetadote is 300 mg/kg given as 3 separate doses and administered over a total of 21 hours. Please refer to the guidelines below for dose preparation based upon patient weight. The total volume administered should be adjusted for patients less than 40 kg and for those requiring fluid restriction (see Tables 1 and 2).
2.1 Administration Instructions (Three–Bag Method: Loading, Second and Third Dose)
Dosing for Patients who weigh 5 kg to 20 kg (Table 1):
Loading Dose: 150 mg/kg diluted in 3 mL/kg of diluent* administered over 1 hr
Second Dose: 50 mg/kg diluted in 7 mL/kg of diluent* administered over 4 hrs
Third Dose: 100 mg/kg diluted in 14 mL/kg of diluent* administered over 16 hrs
See also Section 2.2 Volume Adjustment: Patients less than 40 kg and Requiring Fluid Restriction
Dosing for patients who weigh 21 kg to 40 kg (Table 2):
Loading Dose: 150 mg/kg diluted in 100 mL of diluent* administered over 1 hr
Second Dose: 50 mg/kg diluted in 250 mL of diluent* administered over 4 hrs
Third Dose: 100 mg/kg diluted in 500 mL of diluent* administered over 16 hrs
See also Section 2.2 Volume Adjustment: Patients less than 40 kg and Requiring Fluid Restriction.
Dosing for patients who weigh 41 kg to 100 kg (Table 3):
Loading Dose: 150 mg/kg diluted in 200 mL of diluent* administered over 1 hr
Second Dose: 50 mg/kg diluted in 500 mL of diluent* administered over 4 hrs
Third Dose: 100 mg/kg diluted in 1000 mL of diluent* administered over 16 hrs
Patients Weighing More Than 100 kg
No specific studies have been conducted to eva luate the use of or necessity of dosing adjustments in patients weighing over 100 kg. Limited information is available regarding the dosing requirements of patients that weigh more than 100 kg. The dose of Acetadote recommended in these patients should be a loading dose of 15,000 mg infused over a period of one hour followed by a first maintenance dose of 5,000 mg over 4 hours and a second maintenance dose of 10,000 mg over 16 hours (See Table 3).
Continued Therapy beyond 21 Hours
While there is no clinical trial data to support infusions beyond 21 hours there is literature that supports continued infusion of acetylcysteine in some rare instances. In cases of suspected massive overdose, or with concomitant ingestion of other substances, or in patients with preexisting liver disease, the absorption and/or the half-life of acetaminophen may be prolonged, in such cases consideration should be given to the need for continued infusion of N-acetylcysteine beyond 21 hours. Acetaminophen levels and ALT/AST & INR should be checked before the end of the 21-hour infusion. If acetaminophen levels are still detectable, or in cases in which the ALT/AST are still increasing or the INR remains elevated, the infusion should be continued, and the treating physician should contact a US regional poison center at 1-800-222-1222, or alternatively, a “special health professional assistance line for acetaminophen overdose” at 1-800-525-6115 for assistance with dosing recommendations.
2.2 Volume Adjustment: Patients less than 40 kg and Requiring Fluid Restriction
The total volume administered should be adjusted for patients less than 40 kg and for those requiring fluid restriction. To avoid fluid overload, the volume of diluent should be reduced as clinically needed. If the volume of the infusion is not adjusted, fluid overload can occur, potentially resulting in hyponatremia, seizure and death. [see Dosage and Administration (2)].
|
|
