Inhaled Nitrite to Treat Pulmonary Hypertension Receives US Patent

The use of nitrite salts for the treatment of cardiovascular conditions, such as pulmonary hypertension, is now patented by the U.S. Patent and Trademark Office (USPTO). The new patent (US 20060182815 A1) was awarded to Gordon G. Power with Loma Linda University, and a team of investigators from several other universities, for a discovery supported in part by National Institute of Health grants, the university announced in a press release.

Dr. Gordon G. Power. Photo credit: Loma Linda University

This past decade has seen an increase in the understanding of the critical role of nitric oxide as a blood vessel dilator, and in its contributions to regulating blood flow and cardiovascular homeostasis. Nitric oxide can be oxidized in the blood to nitrite, an effective vasodilator.

The new patent was given for methods that include the inhalation of therapeutically effective quantities of sodium nitrite for pulmonary hypertension, a condition characterized by a high pressure in blood vessels from the heart to the lungs. Due to its vasodilatory effects, sodium nitrite decreases pulmonary artery blood pressure. What makes sodium nitrite distinctive in this case is the fact that it is inhaled as an aerosol, limiting its effects to the lungs and avoiding side effects from systemic actions.

Phase 2 clinical trials are being conducted to evaluate the safety of sodium nitrite in the treatment of cardiovascular conditions, a necessary step before U.S. Food and Drug Administration (FDA) approval can be sought for its use in the clinic. One such trial (NCT01431313), now taking place at the University of Pittsburgh, is currently recruiting about 50 pulmonary arterial hypertension patients to evaluate escalating doses of inhaled nitrate. More information is available through the trial’s clinical trials.gov website, or by clicking on the trial’s identification number, above.

According to the release, it has been determined that administration of pharmaceutical-grade nitrite salts is beneficial in the regulation of the cardiovascular system. These findings enable approaches to prevent and treat cardiovascular-related diseases, including pulmonary hypertension, high blood pressure, cerebral vasospasm and tissue ischemia-reperfusion injury. In addition, the use of nitrite salts also provides ways to increase blood flow to tissues, for example, to tissues in regions of low oxygen tension.

Arlin Blood, PhD, is also continuing to lead studies on nitrite and other metabolites of nitric oxide in the Center for Perinatal Biology.