With oral administration forms of acetylcysteine no cases of toxic overdose were observed so far. Volunteers were treated for 3 months with a daily dose of 11.6 g, without that severe side effects were observed. Oral doses of up to 500 mg acetylcysteine/kg body weight were tolerated without toxic symptoms.
Symptoms of Intoxication: Overdosage may lead to gastrointestinal symptoms like nausea, vomiting and diarrhea. In infants there is the danger of hypersecretion.
Therapy of Intoxication: Symptomatic treatment if necessary.
From the I.V. acetylcysteine treatment in case of paracetamol intoxication in humans there is experience with daily maximum doses up to 30 g of acetylcysteine. The I.V. application of highly concentrated acetylcysteine especially in case of fast application has lead to partly irreversible "anaphylactoid" reactions.