Delayed toxidromes. 
Some toxins do not result in clinical manifestations until several hours after exposure.  This article reviews those agents that may cause delayed-onset toxicity.  They are organized into four classes: specific pharmaceuticals, biologicals, pharmaceutical dosage forms, and chemicals.  There are five basic mechanisms for delayed toxicity: delayed absorption, distribution factors, metabolic factors, cellular and organ capacity effects, and unknown.  Scientific evidence for delayed-onset of effects varies considerably among the individual toxins.