Generic Name:

Acetylcysteine

Trade Name:

Acetadote® (IV formulation), Mucomyst® (po/inhalation form)

Action:

Believed to act as glutathione substitute and directly combine with the toxic acetaminophen metabolite. May increase oxygen delivery, may enhance hepatosplanchnic perfusion

Indications:

Acetaminophen (Tylenol®)-overdose: IV use of acetylcysteine is restricted to patients meeting one, or more, of the following criteria:

• Severe emesis; patient refractory to antiemetics and nasogastric tube
• Gastrointestinal obstruction or bleeding
• Medical and/or surgical conditions precluding use of oral acetylcysteine
• Coingestion of iron, lithium, sustained release or enteric coated meds, and/or illicit drug packets, necessitating ongoing gastrointestinal decontamination

Acute Liver Falure (non-acetaminophen induced) patients meeting the following criteria:

• Acute Liver Failure (non acetaminophen induced)
• Grade I & II Hepatic Encephalopathy
• High Risk Situations (non-encephalopathic)

MUST BE APPROVED BY LIVER SERVICE ATTENDING MD (OR COVERING ATTENDING ON WEEKENDS)

Approval will be for 72 hours (longer use at discretion of Liver Service Attendng MD.)

Administration Guidelines:

Usual Dosage Range and Route:

  Dosage for acetaminophen overdose:.

•  DOSE (IV) : Loading: 150 mg/kg in 200 mL D5W x 1 dose over 15 minutes. Then 50 mg/kg in 500 mL D5W x 1 dose over 4 hrs. Then 100 mg/kg in 1000 mL D5W x 1 dose over 16 hrs.

•  DOSE (PO) : 140 mg/kg x 1 dose, then 70 mg/kg every 4 hours x 17 doses

Dosage for non-acetaminophen induced acute liver failure:

• Dosage(IV):

Hours 0-24:

• Bag 1: 150mg/kg (in 2000ml D5W) over 1 hour(LOAD)
• Bag 2: 50mg/kg (in 500ml D5W) over 4 hours
• Bag 3: 125mg/kg (in 1000ml D5W) over 19 hours

Hours 24-28:

• Bag 1: 150mg/kg (in 1000ml D5W) over 24 hours

Hours 48-72:

• Bag 1: 150mg/kg (in 1000ml D5W ) over 24 hours

Treatment will be for 72 hours(or longer at discretion of Liver Service Attending MD)

Special Considerations:

• IV FORM NOT TO BE USED FOR: prevention of contrast-induced nephropathy (acetylcysteine only administered orally; dose: 600 mg po bid)
• Acetylcysteine IV is contraindicated in patients with hypersensitivity or previous anaphylactoid reactions to acetylcysteine or any components in the preparation-
• Patient to remain on IV acetylcysteine until completion of therapy; pt cannot be switched to oral therapy
• Requires dedicated IV line; pharmacy mixes all doses
• Manufacturer recommends treatment within 10 hours of overdose, but favorable results have been seen in some patients up to 24 hours after overdose
• MD must calculate dose for pt, order must contain dose and pt weight

Precautions and Side Effects:

• Respiratory: bronchospasm, bronchoconstriction, respiratory distress
• Nausea/vomiting
• Anaphylactoid reaction: treat with diphenhydramine; some patients may require epinephrine - Tachycardia, Hypotension/Hypertension- Women who are breastfeeding

Non-acetaminophen induced acute liver failure

•  Cardiac monitoring for initial infusion(load) (monitor for arrhythmias, bradycardia)

•  Confirmed acetaminophen toxicity

•  Pregnancy

•  Severe septic shock

•  Cerebral herniation

•  Grade IV Hepatic Encephalopathy (unresponsive coma)