Unlike an allergic reaction (a normal reaction from the body's immune system to an allergen) a POISONING/OVERDOSE event is one that involves a chemical action that can damage the body's structures or impair the body's normal function.

It is imperative that the healthcare provider recognize that a POISONING/OVERDOSE event has occurred, and to initiate 'treatment' immediately.

Unlike an allergic reaction, the specific POISON or abused substance IS of primary interest, because, unlike the allergic reaction, we will NOT be treating the symptoms, but rather trying to reverse the action of the substance.

Immediate contact with MEDICAL CONTROL is highly encouraged.  Based on the substance involved, the time lapse since administration, the route of administration, the age, size, and weight of the patient, the initial response to the substance by the patient, deviations in the patient's vital signs and/or initial response since administration, and the distance from the nearest appropriate medical facility, MEDICAL CONTROL will want the opportunity to make crucial decisions regarding this patient's course of medical action.

Based on the foregoing paragraph, it becomes apparent that the on-scene healthcare provider must 'collect' a great deal of information before contacting medical control, AND is 'encouraged' to contact medical control IMMEDIATELY.  This equates to "NO TIME."  You have no time to do what needs to be done,  and you are already too late, when you first arrive.  So you had best better arrive with a  proper mental attitude.  You MUST IMMEDIATELY take charge of the situation, collect the information needed by medical control and relay that information to medical control NOW.

Knowing what substance the patient took will be very useful, because it will suggest the response and the severity of the response with which the patient will present.  That's actually a two-way street, because when you are unable to ascertain the substance, but are presented with a 'response' you should be able to suggest the substance (or class of substances) taken.  For that reason, we suggest that you spend some time familiarizing yourself with the signs and symptoms of each of the different classes of drugs and of FOOD POISONING, PLANT POISONING, and some of the less popular substances (alcohol and tobacco.)

That pretty much encapsulates our addition to the text book subject material.

In closing we would just remind the reader that this event may not have been intentional.  If this is an accidental poisoning, be certain to perform a thorough scene assessment, in order to provide for the safety of yourself, your partner, and the general public, as well as the continued safety of the patient.