Hidonac Special Precautions

The possible presence of sulfurous odor does not indicate an alteration of Hidonac but is characteristic of NAC, being the active ingredient. The administration of NAC at high doses may reduce the prothrombin time. However, it is not established whether this is due to a biological action of NAC or the result of an analytical interference. In any way, the monitoring of coagulation factors is advisable, particularly in case of liver transplantation. N-acetylcysteine may interfere with the determination of salicylates (colorimetric method) and with the determination of plasma and urinary ketones (nitroprusside test).
Anaphylactic reactions may occur when IV acetylcysteine is directly administered at high doses as well as when very fast rate is used. Treatment of those reactions must be symptomatic. Therefore, Hidonac must be administered as described in Dosage & Administration. Patients suffering from bronchial asthma or with a history of asthma must be closely controlled since bronchospasm may occur during treatment. In such event, the treatment must be immediately suspended. Intravenous administration must be done in a hospital under strict medical surveillance.
Use in pregnancy & lactation: Evaluation of experimental animal studies does not indicate teratogenic effects. The decision to use NAC at antidotal doses during pregnancy and lactation should be based on assessment of the benefit-to-risk ratio, taking into consideration the particular characteristic of each case and in particular, the risk for the mother and fetus induced by toxicant in the absence of specific treatment. In any case, lactation must be suspended in case of poisoning.