Hidonac Special Precautions

Acetylcysteine should be given by intravenous route under strict medical supervision. The undesirable effects following acetylcysteine intravenous perfusion are more likely to appear if the drug is administered too quickly or in an excessive amount. It is therefore recommended to strictly follow the indications reported under Dosage & Administration.
Anaphylactoid reactions: Anaphylactoid/hypersensitivity reactions occur with acetylcysteine, particularly with the initial loading dose. The patient should be carefully observed during this period for signs of an anaphylactoid reaction. In very rare cases these reactions have been fatal.
Anaphylactoid/hypersensitivity reactions to acetylcysteine usually occur between 15 and 60 minutes after the start of the infusion and, in many cases, symptoms are relieved by stopping the infusion. An antihistamine drug may be necessary, and occasionally corticosteroids may be required.
Most anaphylactoid reactions can be managed by temporarily suspending the acetylcysteine infusion, administering appropriate supportive care and restarting at a lower infusion rate. Once an anaphylactoid reaction is under control, the infusion can normally be restarted at an infusion rate of 50 mg/kg over 4 hours, followed by the final 16-hour infusion (100 mg/kg over 16 hours).
Bronchial asthma: There is some evidence that patients with a history of atopy and asthma may be at increased risk of developing an anaphylactoid reaction.
Patients suffering from bronchial asthma must be closely monitored during therapy. Should bronchospasm occur, acetylcysteine must be stopped immediately and appropriate treatment must be initiated.
Fluid and electrolytes: Caution should be used for administration of antidotal doses in patients with body weight less than 40 kilograms because of the possible risk of fluid overload with subsequent hyponatremia, seizures, and death. It is therefore recommended to strictly follow the indications reported under Dosage & Administration.
Coagulation: Acetylcysteine administration at antidotal dosages may prolong prothrombin time (decrease in prothrombin index, increase in INR).
Information on excipients: This medicinal product contains 748 mg sodium (main component of cooking/table salt) in each vial (32.5 mmol), equivalent to 37.4 % of the WHO recommended maximum daily intake of 2 g sodium for an adult.
A mild smell of sulphur does not indicate an alteration of the product but pertains to the specific nature of the active ingredient.
Effects on ability to drive and use machines: Acetylcysteine has no known influence on the ability to drive and use machines.
Use in children and adolescents: The same warnings and precautions reported for adults apply to children and adolescents.