Answer
Acetylcysteine provides a source equivalent to cysteine within the amino-acid mixture; it is not used here as a mucus-thinning treatment or antidote.
Sources for this answer
- Aminoplasmal 15% Solution for Infusion — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.