The initial transient hyperpnea may be followed by a feelings of anxiety or apprehension, agitation, vertigo, a feeling of weakness, nausea with or without vomiting, and muscular trembling. Later, consciousness is lost, respiration decreases in rate and depth, and convulsions, apnea, and cardiac dysrhythmias and standstill follow. Because this cascade of events is prolonged, diagnosis and successful treatment are possible. The effects of cyanogen chloride include those described for hydrogen cyanide. Cyanogen chloride is also similar to the riot control agents in causing irritation to the eyes, nose, and airways as well as marked lacrimation, rhinorrhea, and bronchosecretions.
Physical findings are few and non-specific.
The two that are said to be characteristic are in fact not always observed. The first is severe respiratory distress in an acyanotic individual. However, cyanide victims may have normal appearing skin and may even be cyanotic, although cyanosis is not classically associated with cyanide poisoning. These may progress to severe effects if exposure continues. The time of onset of these effects depends on the concentration, but is often within minutes after start of exposure.