The present invention is directed to a method of treating a subject for a pulmonary disease by administering a therapeutically effective amount of a compound of the formula:wherein R1, R2 or R3 are each independently a C1 to C6 alkyl, a halogen, a sulfate, or a phosphate. The pulmonary disease in the subject can be hypoxic pulmonary vasoconstriction, pulmonary edema, pulmonary hypertension, asthma, chronic obstructive pulmonary disease, cystic fibrosis, interstitial fibrosis, high altitude residence, sleep apnea syndrome, atrial septal defects, and pulmonary diseases associated with other conditions. If this same compound is modified so that R1, R2 or R3 each independently is a C1 to C6 alkyl and the compound is not a carbonic acid inhibitor, it can be administered to a subject to block hypoxic pulmonary vasoconstriction and/or prevent high altitude pulmonary edema. Additional aspects of the present invention include an inhalable composition comprising the compound of the above formula without modification and an inhalable carrier, as well as the above modified compound.