Acetylcysteine

Name: Acetylcysteine

Uses for Acetylcysteine

Antidote for Acetaminophen Overdosage

Treatment of acetaminophen overdosage.102 103 104 108 Optimal if given within 8 hours of acetaminophen ingestion;109 may be effective when given ≥24 hours after ingestion.105 106

Prevention of Nephropathy Associated with Radiographic Contrast Media

Has been used to prevent radiographic contrast media-induced nephropathy†.100 101 110 111 112 113 114 116 117 Efficacy for this indication not established; additional study needed.110 115 117

Mucolytic Uses

Adjunctive treatment for patients with abnormal, viscid, or inspissated mucous secretions associated with conditions such as acute and chronic bronchopulmonary disorders (e.g., pneumonia, bronchitis, emphysema, tracheobronchitis, chronic asthmatic bronchitis, tuberculosis, bronchiectasis, primary amyloidosis of the lung); atelectasis caused by mucus obstruction; pulmonary complications of cystic fibrosis; pulmonary complications of thoracic and cardiovascular surgery; and post-traumatic chest conditions.102 103 104

Used during anesthesia and in the preparation of patients for bronchograms, bronchospirometry, bronchial wedge catheterization, and other diagnostic bronchial studies.102 103 104

Tracheostomy care.102 103 104

Acetylcysteine Dosage and Administration

General

  • Determine plasma or serum acetaminophen concentrations as soon as possible (but no sooner than 4 hours) after ingestion.107 May be appropriate to obtain an additional sample at 4–6 hours after initial sample if extended-release acetaminophen preparation was ingested.107

  • Use plasma or serum acetaminophen concentrations in conjunction with a nomogram to estimate potential for hepatotoxicity and necessity of acetylcysteine therapy.105 107

  • Full course of acetylcysteine therapy indicated if initial plasma or serum acetaminophen concentrations fall on or above the dashed line on the nomogram.105 (See nomogram.)106 107

  • Assistance available from a regional poison center at 800-222-1222 or an assistance line for acetaminophen overdosage at 800-525-6115.108

Nomogram relating plasma or serum acetaminophen concentration and probability of hepatotoxicity at varying intervals following ingestion of a single toxic dose of acetaminophen. Modified from Rumack BH, Matthew H. Acetaminophen poisoning and toxicity. Pediatrics. 1975; 55:871-6. American Academy of Pediatrics 1975. And from Rumack BH et al. Acetaminophen overdose. Arch Intern Med. 1981; 141:380-5. American Medical Association.

Multiple Supratherapeutic Acetaminophen Doses

  • Guidelines for the treatment of ingestions involving multiple, higher-than-recommended acetaminophen doses over an extended period of time currently are not available.118 Plasma AST/ALT concentrations and plasma or serum acetaminophen concentrations have been used to estimate potential for hepatotoxicity and necessity of acetylcysteine therapy.108 118

  • Assistance available from a regional poison center at 800-222-1222 or an assistance line for acetaminophen overdosage at 800-525-6115.108

Administration

Administer orally or by IV infusion as an antidote for acetaminophen overdosage; administer by oral inhalation or intracheal instillation for mucolytic uses.102 103 104 108

Has been administered orally100 110 117 or IV110 117 for prevention of radiographic contrast media-induced nephropathy†.

Oral Administration

Usually administered as a 5% solution.102 103 104 Dilute 20% solution 1:3 with diet soft drink.102 103 104

Initiate antiemetic therapy or administer via duodenal tube if persistently unable to retain orally administered drug.107

NG Tube

Administer as 5% solution; may use water as the diluent.102 103 104

IV Administration

For solution and drug compatibility information, see Compatibility under Stability.

Administer as a loading dose, followed by a first maintenance dose, then a second maintenance dose.108

Injection concentrate must be diluted prior to IV administration.108

Dilution

Dilute dose with an appropriate volume of 5% dextrose injection (see Table 1).108

Adjust total volume for patients who weigh <40 kg (see Table 1) and for those requiring fluid restriction.108

Table 1. Recommended Volumes of 5% Dextrose Injection for Dilution of IV Acetylcysteine Doses

 

Volume of Diluent for Indicated Dose

Patient’s Weight (kg)

Loading Dose

First Maintenance Dose

Second Maintenance Dose

≥40

200 mL

500 mL

1 L

30

100 mL

250 mL

500 mL

25

100 mL

250 mL

500 mL

20

60 mL

140 mL

280 mL

15

45 mL

105 ml

210 mL

10

30 mL

70 ml

140 mL

Rate of Administration

Loading dose: Infuse over 60 minutes.108 109

First maintenance dose: Infuse over 4 hours.108

Second maintenance dose: Infuse over 16 hours.108

Oral Inhalation and Intratracheal Instillation

For drug compatibility information, see Compatibility under Stability.

Use 20% acetylcysteine solution undiluted or dilute with 0.9% sodium chloride injection or inhalation solution or sterile water for injection or inhalation.102 103 104

May use 10% acetylcysteine solution undiluted.102 103 104

Dosage

Available as acetylcysteine and acetylcysteine sodium; dosage expressed in terms of acetylcysteine.102 103 103 108

Pediatric Patients

Antidote for Acetaminophen Overdosage Oral

Loading dose: 140 mg/kg, administered as soon as possible.102 103 104 Maintenance dosage, if indicated: 70 mg/kg every 4 hours for 17 doses.102 103 104

If patient vomits a loading or maintenance dose within 1 hour of administration, repeat the dose.107

IV

Loading dose: 150 mg/kg, administered as soon as possible.107 108

First maintenance dose: 50 mg/kg.107 108

Second maintenance dose: 100 mg/kg.107 108

Mucolytic Uses Nebulization

Face mask, mouthpiece, or tracheostomy: 3–5 mL of the 20% solution or 6–10 mL of the 10% solution 3 or 4 times daily; alternatively, 1–10 mL of the 20% solution or 2–20 mL of the 10% solution every 2–6 hours.102 103 104

Tent or croupette: Volume of acetylcysteine solution should be sufficient to maintain a very heavy mist in the tent or croupette for the desired period; maintenance of heavy mist may require up to 300 mL of the 10 or 20% solution for a single, continuous treatment.102 103 104 Administer intermittently or for continuous prolonged periods.102 103 104

Direct Instillation

1–2 mL of a 10–20% solution as often as every hour.102 103 104

Intratracheal Instillation

Instillation through a percutaneous intratracheal catheter: 1–2 mL of the 20% solution or 2–4 mL of the 10% solution every 1–4 hours via a syringe attached to the catheter.102 103 104

Instillation through a catheter into the trachea: 2–5 mL of the 20% solution via a syringe attached to the catheter.102 103 104

Diagnostic Bronchial Studies Nebulization

2 or 3 doses of 1–2 mL of the 20% solution or 2–4 mL of the 10% solution prior to the procedure.102 103 104

Intratracheal Instillation

2 or 3 doses of 1–2 mL of the 20% solution or 2–4 mL of the 10% solution prior to the procedure.102 103 104

Tracheostomy Care Intratracheal Instillation

1–2 mL of a 10–20% solution into the tracheostomy every 1–4 hours.102 103 104

Adults

Antidote for Acetaminophen Overdosage Oral

Loading dose: 140 mg/kg, administered as soon as possible.102 103 104 Maintenance dosage, if indicated: 70 mg/kg every 4 hours for 17 doses.102 103 104

If patient vomits a loading or maintenance dose within 1 hour of administration, repeat the dose.107

IV

Loading dose: 150 mg/kg, administered as soon as possible.108

First maintenance dose: 50 mg/kg.108

Second maintenance dose: 100 mg/kg.108

Prevention of Nephropathy Associated with Radiographic Contrast Media† Oral

600 mg twice daily, given the day before and the day of contrast media administration (total of 4 doses), has been used.100 110 117 Other dosage regimens have been investigated.110 117

Mucolytic Uses Nebulization

Face mask, mouthpiece, tracheostomy: 3–5 mL of the 20% solution or 6–10 mL of the 10% solution 3 or 4 times daily; alternatively, 1–10 mL of the 20% solution or 2–20 mL of the 10% solution every 2–6 hours.102 103 104

Tent or croupette: Volume of acetylcysteine solution should be sufficient to maintain a very heavy mist in the tent or croupette for the desired period; maintenance of heavy mist may require up to 300 mL of the 10 or 20% solution for a single, continuous treatment.102 103 104 Administer intermittently or for continuous prolonged periods.102 103 104

Direct Instillation

1–2 mL of a 10–20% solution as often as every hour.102 103 104

Intratracheal Instillation

Instillation through a percutaneous intratracheal catheter: 1–2 mL of the 20% solution or 2–4 mL of the 10% solution every 1–4 hours via a syringe attached to the catheter.102 103 104

Instillation through a catheter into the trachea: 2–5 mL of the 20% solution via a syringe attached to the catheter.102 103 104

Diagnostic Bronchial Studies Nebulization

For diagnostic bronchial studies: 2 or 3 doses of 1–2 mL of the 20% solution or 2–4 mL of the 10% solution prior to the procedure.102 103 104

Intratracheal Instillation

For diagnostic bronchial studies: 2 or 3 doses of 1–2 mL of the 20% solution or 2–4 mL of the 10% solution prior to the procedure.102 103 104

Tracheostomy Care Intratracheal Instillation

1–2 mL of a 10–20% solution into the tracheostomy every 1–4 hours.102 103 104

Special Populations

Hepatic Impairment

Antidote for Acetaminophen Overdosage IV

Published reports do not indicate that the dose should be reduced in patients with hepatic impairment.108 Data are not available to determine whether dosage adjustment is needed in patients with hepatic cirrhosis.108

Renal Impairment

Antidote for Acetaminophen Overdosage IV

Data are not available to determine whether dosage adjustment is needed in patients with moderate or severe renal impairment.108

Stability

Storage

Oral, Oral Inhalation, Intratracheal Instillation

Solution

15–30°C.102 103 104 Use diluted solutions within 1 hour.102 103 104 Store undiluted solution in opened vials in refrigerator; use within 96 hours.102 103 104 Do not store admixtures.102 103 104

Parenteral

Injection Concentrate for IV Infusion

20–25°C.108

Presence of light pink to light purple color in solution does not affect the quality of the product.108

Following dilution with 5% dextrose, stable at controlled room temperature for 24 hours.108

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Parenteral

Solution Compatibility

Compatible108

Dextrose 5% in water

Sodium chloride 0.45%

Drug Compatibility Y-Site CompatibilityHID

Incompatible

Cefepime HCl

Ceftazidime

Oral Inhalation, Intratracheal Instillation

Presence of light purple color in solution does not appreciably affect potency.102 103 104 a

Drug Compatibility

Incompatible with oxidizing agents.a

Admixture Compatibility103104

Compatible

Cocaine HCl

Dexamethasone sodium phosphate

Epinephrine HCl

Gentamicin sulfate

Halothane

Isoetharine HCl

Isoproterenol HCl

Lidocaine HCl

Lincomycin HCl

Nitrous oxide

Phenylephrine HCl

Polymyxin B sulfate

Tetracaine HCl

Vancomycin HCl

Incompatible

Amphotericin B

Ampicillin sodium

Erythromycin lactobionate

Before Using acetylcysteine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For acetylcysteine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to acetylcysteine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies on the relationship of age to the effects of acetylcysteine have not been performed in the pediatric population. However, no pediatric-specific problems have been documented to date.

Geriatric

Although appropriate studies on the relationship of age to the effects of acetylcysteine have not been performed in the geriatric population, no geriatric-specific problems have been documented to date. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require caution and an adjustment in the dose for patients receiving acetylcysteine.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving acetylcysteine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using acetylcysteine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Carbamazepine
  • Nitroglycerin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of acetylcysteine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Bleeding in the esophagus or
  • Stomach ulcers, or history of—May increase risk for more serious side effects.
  • Congestive heart failure or
  • Hypertension (high blood pressure) or
  • Kidney disease—acetylcysteine contains sodium, which can make these conditions worse.

Proper Use of acetylcysteine

acetylcysteine will be given to you by a nurse or other healthcare professional while you are in the hospital. It works best when it is given as close to the time of overdose as possible. The more time that goes by after the overdose, the less effective the medicine will be in protecting your liver.

acetylcysteine comes with a patient information leaflet. Read and follow the instructions carefully. Ask your doctor if you have any questions.

The effervescent tablets should be dissolved in water before taking. Follow the instructions provided by your doctor. The mixed solution should be taken within 2 hours.

There is usually a total of 17 doses of acetylcysteine, taken about 4 hours apart. If you vomit within 1 hour after you take your medicine, you will need to take another dose to make up for it.

Pharmacology

Acetaminophen overdose: Acetylcysteine acts as a hepatoprotective agent by restoring hepatic glutathione, serving as a glutathione substitute, and enhancing the nontoxic sulfate conjugation of acetaminophen.

Mucolytic: Exerts mucolytic action through its free sulfhydryl group which opens up the disulfide bonds in the mucoproteins thus lowering mucous viscosity.

Prevention of contrast-induced nephropathy (off-label use): The presumed mechanism in preventing contrast-induced nephropathy is its ability to scavenge oxygen-derived free radicals and improve endothelium-dependent vasodilation.

Distribution

Vdss: 0.47 L/kg

Metabolism

Undergoes extensive first pass metabolism to form cysteine and disulfides (N,N-diacetylcysteine and N-acetylcysteine); cysteine is further metabolized to form glutathione and other metabolites

Excretion

Urine (13% to 38%)

Dosing Pediatric

Acetaminophen overdose: Infants, Children, and Adolescents: Refer to adult dosing.

Adjuvant therapy in respiratory conditions:

Note: Patients should receive an aerosolized bronchodilator 10 to 15 minutes prior to acetylcysteine

Inhalation, nebulization (face mask, mouth piece, tracheostomy): Acetylcysteine 10% and 20% solution (dilute 20% solution with sodium chloride or sterile water for inhalation); 10% solution may be used undiluted.

Infants: 1 to 2 mL of 20% solution or 2 to 4 mL 10% solution until nebulized given 3 to 4 times/day

Children: Refer to adult dosing.

Inhalation, nebulization (tent, croupette): Children: Refer to adult dosing.

Uses of Acetylcysteine

Acetylcysteine is used in the treatment of:

  • Amyloidosis
  • Bronchiectasis
  • Bronchitis
  • Cystic Fibrosis
  • Drug Toxicity
  • Pneumonia
  • Pulmonary Emphysema
  • Respiratory Distress Syndrome, Adult

Acetylcysteine is used in the prevention of:

  • Kidney Tubular Necrosis, Acute
  • Postoperative Complications

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Forms of Medication

Acetylcysteine is available in the following forms:

  • Extended Release Capsule
  • Inhalant Solution
  • Injectable Solution
  • Ophthalmic Solution
  • Oral Capsule
  • Oral Tablet

Interactions

See also How to Use section.

Your doctor or pharmacist may already be aware of any possibledrug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use.

This medication may interfere with certain laboratory tests (including urine ketone test), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

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