The main side effects with N-acetyl-cysteine have to do with its short half life and toxicity. They include the following:
•Short half life, so has to be administered several times a day to be effective
•Rash
•Wheezing
•Nausea
•Anaphylaxis-like allergic reaction, which may include difficulty breathing due to bronchospasm*
•Decrease in blood pressure
•Angioedema ( rapid swelling of the skin)
•Vomiting
•Cramps
•Diarrhea