Inhaled nitric oxide and pulmonary vasoreactivity.

Inhaled nitric oxide is a ubiquitous molecule which is produced endogenously and is also found in air pollution and in cigarette smoke. After describing the chemistry of NO, we review its history from the first description in 1980 to the current clinical indications. The biosynthesis of NO, its effects on pulmonary vasoreactivity, and the administration of inhaled NO will be described. The indications, uses, and side effects of inhaled NO are discussed with an emphasis on withdrawal of NO therapy, specifically the "rebound" phenomenon. Possible drug interactions are listed. Inhaled nitric oxide is here to stay, and future studies will provide more information on its therapeutic dose, duration and potential toxicity.