Poisoning from the ingestion or inhalation of cyanide (found in bitter almond oil and wild cherry syrup; common in smoke from fires and as an industrial chemical); causes rapid heart rate, drowsiness, convulsions, and frequently death within 15 minutes. Treatment involves oxygen and a specific group of antidotes.
Cyanide inhibits cellular respiration by binding rapidly and reversibly with the enzyme, cytochrome oxidase. Effects of poisoning are due to tissue hypoxia. Cyanide is toxic by inhalation, ingestion and prolonged skin contact, and acts extremely quickly once absorbed. Following inhalation of hydrogen cyanide gas, deaths can occur within minutes. Ingestion of inorganic cyanide salts may produce symptoms within 10 minutes, again proceeding rapidly to death. On a full stomach, effects may be delayed for an hour or more. Signs of cyanide poisoning are headache, dizziness, vomiting, weakness, ataxia, hyperventilation, dyspnoea, hypotension and collapse. Loss of vision and hearing may occur, then coma and convulsions. Other features include cardiac arrhythmias and pulmonary oedema. Patients may have a lactic acidosis. Their arterial oxygen tension is likely to be normal, but their venous oxygen tension high and similar to that of arterial blood.
Intoxication with any of several cyanide-containing compounds, very potent blockers of cellular oxygenation. They inhibit respiration by blocking oxidative phosphorylation at the cellular level.