A response to glucagon makes beta-blocking drugs more likely.
A response to bicarbonate (indicated if the patient is acidotic) suggests TCAs or antiarrhythmic drug poisoning.
Calcium will reverse CCB poisoning but may exacerbate a number of other poisonings. Its use is not recommended unless the diagnosis is probable.

Dextropropoxyphene is the only one of the drugs that has a classical antagonist (naloxone). Reversal of sedation, but not cardiac effects, is seen.
A response to glucagon (which can usually be given safely) suggests beta blocking drug poisoning.
A response to bicarbonate or hyperventilation suggests TCA or quinine poisoning.
A response to calcium (a routine trial of this therapy is NOT recommended) suggests calcium channel blockade.

Physostigmine will temporarily reverse anticholinergic delirium.
There is no completely effective antiserotonergic drug but cyproheptadine or chlorpromazine will sometimes improve delirium.
The majority of these patients will respond to benzodiazepines. This is of no diagnostic value in itself but may enable a sensible history to be obtained.
BETA BLOCKING DRUGS ARE CONTRAINDICATED IN AMPHETAMINE/COCAINE INGESTION.

A response to glucagon makes beta-blocking drugs more likely.
A response to bicarbonate (indicated if the patient is acidotic) suggests TCAs or antiarrhythmic drug poisoning.
Calcium will reverse CCB poisoning but may exacerbate a number of other poisonings. Its use is not recommended unless the diagnosis is probable.

ALL PATIENTS WITH SEIZURES SHOULD BE GIVEN GLUCOSE!
A response suggests hypoglycaemic drugs, insulin or beta blocking drugs.
Oxygen should also be given to all patients.
A rapid response of seizures to other specific treatments (e.g. pyridoxine for isoniazid) does not always occur.

A response to bicarbonate is seen with cocaine.
Propranolol should not be given as it may worsen myocardial ischaemia in patients with cocaine or amphetamine ingestion though it is an effective treatment for chloral hydrate poisoning.

Bicarbonate should be given to all patients with acidosis. A dramatic response to bicarbonate supports ingestion of TCAs, antiarrhythmic drugs, or cocaine.