Inhaled nitric oxide: well-known and new therapeutic indications

Abstract

The use of nitric oxide is widespread in medical practice. Inhaled form of NO in patients with respiratory disease is especially interesting. As an inhalation therapy, nitric oxide reaches well-ventilated areas of the lungs, having a negligible systemic effect due to its rapid inactivation in the bloodstream. It has long been known that inhaled NO improves oxygenation in various pathological conditions. Low doses of inhaled nitric oxide are known as a vasodilator in patients with pulmonary hypertension, its use is possible even in newborns with hypoxemic respiratory failure and persistent pulmonary hypertension. In turn, high doses are used in the treatment of infectious lung diseases, besides, another surge of scientific interest in nitric oxide arose during the coronavirus pandemic. Although the antimicrobial potential of nitric oxide is widely known, it is little used in clinical practice. Endogenous antimicrobial activity is largely mediated by high local concentrations of NO. Numerous preclinical studies have demonstrated that NO has general static and bactericidal activity against viruses, bacteria, protozoa and fungi/yeast in vitro. Due to the dose-dependent positive and negative effects of NO, safety and efficacy tests of NO and its donors are needed to assess their role in the prevention and treatment of infections. This review provides information on the chemical structure, features of metabolism and delivery of inhaled NO, and also pays special attention to the antimicrobial effect in various diseases of the pulmonological profile.