Contains cardenolides, flavonoids, and triterpenes. Used as an expectorant, tonic, diaphoretic, antispasmodic. The main use is in the treatment of pleurisy (swelling of the lining of the lungs) to relieve the pain and ease breathing. It is also used for coughs, swelling of the air sacs in the lungs (pneumonitis), swelling of the airways (bronchitis), and influenza. It loosens mucus so it can be coughed up