ACETYLCYSTEINE

5 WARNINGS AND PRECAUTIONS Hypersensitivity Reactions: Fatal or life-threatening anaphylaxis, rash, hypotension, wheezing, shortness of breath, and/or bronchospasm have been observed. 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 and acute symptoms have resolved (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; including fatal or life-threatening anaphylaxis, 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) ] . If a severe hypersensitivity reaction occurs, immediately stop the infusion of acetylcysteine and initiate appropriate treatment. 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. These reactions usually occur 30 to 60 minutes after initiating the infusion and often resolve spontaneously despite continued infusion of acetylcysteine. If a reaction to acetylcysteine involves more than simply flushing and erythema of the skin, it should be treated as a hypersensitivity reaction. Management of less severe hypersensitivity reactions should be based upon the severity of the reaction and include temporary interruption of the infusion and/or administration of antihistaminic drugs. The acetylcysteine infusion may be carefully restarted after treatment of the hypersensitivity symptoms has been initiated and acute symptoms have resolved; however, if the hypersensitivity reaction returns upon re-initiation of treatment or increases in severity, acetylcysteine should be discontinued and alternative patient management should be considered. 5.2 Fluid Overload The total volume of acetylcysteine administered should be adjusted for patients less than 40 kg and for those requiring fluid restriction. Intravenous administration of acetylcysteine can cause fluid overload, potentially resulting in hyponatremia, seizure, and death. To avoid fluid overload, use the recommended dilutions [see Dosage and Administration (2.5) ].