Like all medications, Bronchicum can have side effects: Common Side Effects: Hypersensitivity reactions may occur, such as cutaneous rash or nettle rash, as well as swelling in the face, mouth and/or throat associated with shortness of breath. Very Rare Side Effects: Also gastro-intestinal complaints may occur, such as nausea, vomiting, and diarrhea, and very rarely convulsions.