Nitrite ion (NO₂⁻)

The nitrite ion (NO₂⁻) is a symmetric inorganic oxyanion and Lewis base, with a resonance-stabilized two-oxygen structure and a formal negative charge. It is a key intermediate in the environmental nitrogen cycle and is produced by bacterial reduction of nitrate or by various chemical reactions[1][2][3][4][5][6]. Sodium nitrite and similar salts are widely used in food preservation to inhibit bacterial growth. Medically, sodium nitrite and amyl nitrite are utilized as antidotes for cyanide poisoning via chemical conversion. Although nitrite can interact with biological molecules and play indirect roles in disease and therapy, it is not a receptor, enzyme, transporter, or protein target typically modulated by drugs in a structured therapeutic context[3][6]. Nitrite toxicity can arise from excessive ingestion or environmental exposure, leading to oxidation of hemoglobin to methemoglobin (causing hypoxia) and formation of carcinogenic nitrosamines under certain conditions[6]. The nitrite ion is a chemically reactive inorganic anion, not a classical drug target. It is important in chemistry, physiology, environmental toxicology, and food science, but does not correspond to a specific canonical protein therapeutic target such as a receptor or enzyme. Any references to nitrite in drug interactions are via its chemical reactivity, not selective binding or modulation in the usual pharmaceutical sense.

Other names

nitritenitrite anionnitrite (1-)nitrite ion (NO₂⁻)

Acts as source of nitric oxide (vasodilation/mechanism for treating cyanide poisoning) Oxidizes hemoglobin to methemoglobin, which can bind cyanide