Vacha (Calamus) root powder in dosage of 500 mg along with Trikatu powder (250 mg) and milk (250 ml) reduces nasal congestion, body aches, sneezing, sore throat and running nose. It also reduces the inflammation of the pharynx (pharyngitis).
Acorus Calamus has anti-allergic effect. It inhibits the mast cell-dependent anaphylaxis and allergic reactions. (Reference)
It can also be used along with Haldi (Turmeric) for the treatment of allergic disorders of the respiratory tract.
Vacha reduces chest congestion, wheezing, and irritation in the lungs due to excess mucus. The antitussive action also reduces cough. It is mainly effective when cough is productive in nature.
It should be avoided in dry red throat with burning sensation, or dry cough. In that case, Yashtimadhu (Glycyrrhiza Glabra), Vasa (Adhatoda Vasica) and Misri (Sugar) are more beneficial.