This is why I brought a bottle of Benadryl tablets with me.
I had a flu/allergy bout last week in Northern Laos, just south of the China border. When my lungs started filling up I drank lots of hot coffee and took Benadryl. It saved me from pneumonia.
For a day I felt like my head was going to explode, but my chest cleared up real fast.
Benadryl will clear your lungs?