PACKAGE LABEL.PRINCIPAL DISPLAY PANEL

Package/Label Display Panel

Acetylcysteine Solution, USP

20% (200 mg/ml)

5 x 4 ml Vials

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DESCRIPTION SECTION

DESCRIPTION

Acetylcysteine is for inhalation (mucolytic agent) or oral administration (acetaminophen antidote), available as a sterile, unpreserved solution (NOT FOR INJECTION). The solutions contain 20% (200 mg/mL) or 10% (100 mg/mL) acetylcysteine, with disodium edetate in water for injection. Sodium hydroxide and/or hydrochloric acid is added to adjust pH (range 6.0 - 7.5). Acetylcysteine is the N-acetyl derivative of the naturally-occurring amino acid, L-cysteine. The compound is a white crystalline powder with the molecular formula C5H9NO3S, a molecular weight of 163.2, and chemical name of N-acetyl-L-cysteine. Acetylcysteine has the following structural formula:


This product contains the following inactive ingredients:
disodium edetate, sodium hydroxide and water for injection.

CLINICAL PHARMACOLOGY SECTION

CLINICAL PHARMACOLOGY

(Antidotal) Acetaminophen is rapidly absorbed from the upper gastrointestinal tract with peak plasma levels occurring between 30 and 60 minutes after therapeutic doses and usually within 4 hours following an overdose. The parent compound, which is nontoxic, is extensively metabolized in the liver to form principally the sulfate and glucuronide conjugates which are also nontoxic and are rapidly excreted in the urine. A small fraction of an ingested dose is metabolized in the liver by the cytochrome P-450 mixed function oxidase enzyme system to form a reactive, potentially toxic, intermediate metabolite which preferentially conjugates with hepatic glutathione to form the nontoxic cysteine and mercapturic acid derivatives which are then excreted by the kidney. Therapeutic doses of acetaminophen do not saturate the glucuronide and sulfate conjugation pathways and do not result in the formation of sufficient reactive metabolite to deplete glutathione stores. However, following ingestion of a large overdose (150 mg/kg or greater) the glucuronide and sulfate conjugation pathways are saturated resulting in a larger fraction of the drug being metabolized via the P-450 pathway. The increased formation of reactive metabolite may deplete the hepatic stores of glutathione with subsequent binding of the metabolite to protein molecules within the hepatocyte resulting in cellular necrosis.

Acetylcysteine has been shown to reduce the extent of liver injury following acetaminophen overdose. Its effectiveness depends on early oral administration, with benefit seen principally in patients treated within 16 hours of the overdose. Acetylcysteine probably protects the liver by maintaining or restoring the glutathione levels, or by acting as an alternate substrate for conjugation with, and thus detoxification of, the reactive metabolite.

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INDICATIONS & USAGE SECTION

INDICATIONS AND USAGE

Acetylcysteine, administered orally, is indicated as an antidote to prevent or lessen hepatic injury which may occur following the ingestion of a potentially hepatotoxic quantity of acetaminophen.

It is essential to initiate treatment as soon as possible after the overdose and, in any case, within 24 hours of ingestion.

DOSAGE & ADMINISTRATION SECTION

DOSAGE AND ADMINISTRATION

General

Regardless of the quantity of acetaminophen reported to have been ingested, administer acetylcysteine immediately if 24 hours or less have elapsed from the reported time of ingestion of an overdose of acetaminophen. Do not await results of assays for acetaminophen level before initiating treatment with acetylcysteine. The following procedures are recommended:

The stomach should be emptied promptly by lavage or by inducing emesis with syrup of ipecac. Syrup of ipecac should be given in a dose of 15 mL for children up to age 12 and 30 mL for adolescents and adults followed immediately by drinking copious amounts of water. The dose should be repeated if emesis does not occur in 20 minutes. 

In the case of a mixed drug overdose activated charcoal may be indicated. However, if activated charcoal has been administered, lavage before administering acetylcysteine treatment. Activated charcoal adsorbs acetylcysteine in vitro and may do so in patients and thereby may reduce its effectiveness. 

Draw blood for predetoxification acetaminophen plasma assay and baseline SGOT, SGPT, bilirubin, prothrombin time, creatinine, BUN, blood sugar and electrolytes. 

Administer the loading dose of acetylcysteine, 140 mg per kg of body weight. (Prepare acetylcysteine for oral administration as described in the Dosage Guide and Preparation table). 

Determine subsequent action based on predetoxification plasma acetaminophen information. Choose**ONE** of the following four courses of therapy. 

A.

Predetoxification plasma acetaminophen level is clearly in the toxic range (See Acetaminophen Assays - Interpretation and Methodology below):  

Administer a first maintenance dose (70 mg/kg acetylcysteine) 4 hours after the loading dose. The maintenance dose is then repeated at 4-hour intervals for a total of 17 doses. Monitor hepatic and renal function and electrolytes throughout the detoxification process.

B.

Predetoxification acetaminophen level could not be obtained  

Proceed as in A.

C.

Predetoxification acetaminophen level is clearly in the non-toxic range (beneath the dashed line on the nomogram) and you know that acetaminophen overdose occurred at least 4 hours before the predetoxification acetaminophen plasma assays  

Discontinue administration of acetylcysteine.

D.

Predetoxification acetaminophen level was in the non-toxic range, but time of ingestion was unknown or less than 4 hours  

Because the level of acetaminophen at the time of predetoxification assay may not be a peak value (peak may not be achieved before 4 hours post-ingestion), obtain a second plasma level in order to decide whether or not the full 17-dose detoxification treatment is necessary.

If the patient vomits an oral dose within 1 hour of administration, repeat that dose. 

In the occasional instances where the patient is persistently unable to retain the orally administered acetylcysteine, the antidote may be administered by duodenal intubation. 

Repeat SGOT, SGPT, bilirubin, prothrombin time, creatinine, BUN, blood sugar and electrolytes daily if the acetaminophen plasma level is in the potentially toxic range as discussed below.

Preparation of Acetylcysteine for Oral Administration

Oral administration requires dilution of the 20% solution with diet cola or other diet soft drinks, to a final concentration of 5% (see Dosage Guide and Preparation table). If administered via gastric tube or Miller-Abbott tube, water may be used as the diluent. The dilutions should be freshly prepared and utilized within one hour. Remaining undiluted solutions in opened vials can be stored in the refrigerator up to 96 hours.

ACETYLCYSTEINE IS NOT APPROVED FOR PARENTERAL INJECTION.

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CONTRAINDICATIONS SECTION

CONTRAINDICATIONS

There are no contraindications to oral administration of acetylcysteine in the treatment of acetaminophen overdose.

WARNINGS SECTION

WARNINGS

Generalized urticaria has been observed rarely in patients receiving oral acetylcysteine for acetaminophen overdose. If this occurs or other allergic symptoms appear, treatment with acetylcysteine should be discontinued unless it is deemed essential and the allergic symptoms can be otherwise controlled.

If encephalopathy due to hepatic failure becomes evident, acetylcysteine treatment should be discontinued to avoid further administration of nitrogenous substances. There are no data indicating that acetylcysteine influences hepatic failure, but this remains a theoretical possibility.

PRECAUTIONS SECTION

PRECAUTIONS

Occasionally severe and persistent vomiting occurs as a symptom of acute acetaminophen overdose. Treatment with oral acetylcysteine may aggravate the vomiting. Patients at risk of gastric hemorrhage (eg, esophageal varices, peptic ulcers, etc.) should be evaluated concerning the risk of upper gastrointestinal hemorrhage versus the risk of developing hepatic toxicity, and treatment with acetylcysteine given accordingly.

Dilution of the acetylcysteine (see Preparation of Acetylcysteine for Oral Administration) minimizes the propensity of oral acetylcysteine to aggravate vomiting.

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ADVERSE REACTIONS SECTION

ADVERSE REACTIONS

Oral administration of acetylcysteine, especially in the large doses needed to treat acetaminophen overdose, may result in nausea, vomiting and other gastrointestinal symptoms. Rash with or without mild fever has been observed rarely.

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HOW SUPPLIED SECTION

HOW SUPPLIED

Acetylcysteine is available in rubber stoppered glass vials containing 4, 10, or 30 mL. The 20% solution may be diluted to a lesser concentration with either Sodium Chloride for Injection, Sodium Chloride for Inhalation, Sterile Water for Injection, or Sterile Water for Inhalation. The 10% solution may be used undiluted.

Acetylcysteine solution is sterile and can be used for inhalation (mucolytic agent) or oral administration (acetaminophen antidote). Acetylcysteine solution is not for parenteral injection. It is available as:

Acetylcysteine 20% solution (200 mg acetylcysteine per mL). Sterile, not for injection.

NDC 55154-5731-5 Overbagged with five 4 mL vials

Acetylcysteine 10% solution (100 mg acetylcysteine per mL). Sterile, not for injection.

NDC 55154-5730-5 Overbagged with five 4 mL vials

STORAGE AND HANDLING SECTION

STORAGE

Store unopened vials at 20°-25°C (68°-77°F); excursions permitted to 15°-30°C (59°-86°F) (see USP Controlled Room Temperature).

Acetylcysteine solution does not contain an antimicrobial agent, and care must be taken to minimize contamination of the sterile solution. Dilutions of acetylcysteine should be used freshly prepared and utilized within one hour. If only a portion of the solution in a vial is used, store the remaining undiluted portion in a refrigerator and use within 96 hours. A change in color may occur after opening. This does not change the efficacy of the drug.

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SPL UNCLASSIFIED SECTION

DOSAGE GUIDE AND PREPARATION

Doses in relation to body weight are:

Loading Dose of Acetylcysteine**

Estimating Potential for Hepatoxicity

The following nomogram has been developed to estimate the probability that plasma levels in relation to intervals post ingestion will result in hepatoxicity.

** Plasma or Serum Acetaminophen Concentration**** v**** Time Post- acetaminophen Ingestion**

REFERENCES SECTION

REFERENCES

Bonanomi L, Gazzaniga A. Toxicological, pharmacokinetic and metabolic studies on acetylcysteine. Eur J Respir Dis, 1981; 61 (Suppl III): 45-51. 

 Am Rev Respir Dis, 1960; 82:627-639.

Rx Only

IN7504
Rev. 5/14
MG #11105

AMERICAN
REGENT, INC.
SHIRLEY, NY 11967

Distributed By:

Cardinal Health

Dublin, OH 43017

L35753540324

L35753390324

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