0071643192.pdf

TOXICOLOGY

DIAGNOSIS

■ Clinical diagnosis is based on exposure history and physical exam.
■ RBC cholinesterase levels may be indicated in chronic exposures.
■ ECG used to screen for blocks, dysrhythmias.

TREATMENT

■ Supportive care
■ Atropine (very high doses often needed)
■ Hemodynamically unstable bradycardia
■ Excessive secretions—endpoint is drying of airway secretion.
■ Benzodiazepines for seizures and agitation
■ Antidotes
■ Atropine (above)
■ Pralidoxime (2-PAM) for organophophate poisoning.

ANTICOAGULANTS

Warfarin

Warfarin is an oral anticoagulant.

MECHANISM/TOXICITY

■ Blocks conversion of vitamin K to its active form, thereby preventing syn-
thesis of vitamin K–dependent clotting factors (II, VII, IX, X)
■ Effect is delayed until preformed stores of vitamin K and clotting fac-
tors are depleted (typically ≥15 hours).
■ The duration of action may be up to 6 days.
■ Blocks the synthesis of antithrombotic proteins C and S →prothrombotic
period before vitamin K–dependent factors are depleted

TABLE 6.8. Cholinergic Agents

Some Alzheimer medications

Donepezil

Myasthenia gravis medications

Pyridostigmine

Edrophonium

Insecticides

Organophosphate compounds

Carbamate compounds

Chemical weapons

Nerve agents (sarin)

Glaucoma agents

Pilicarpine

Cytocybe and inocybe mushrooms

Warfarin blocks the synthesis

of (vitamin K–dependent)

clotting factors II, VII, IX, X.