0071643192.pdf

TOXICOLOGY

■ Antidotal therapy: Deferoxamine

■ Chelating agent

■ Indications:

■ Systemic illness (severe acidosis, shock)

■ Serum iron levels >500 mcg/dL (with clinical symptoms)

■ Urine color may change to pink-red (“vin-rose”) color when deferoxamine-

iron complex excreted in urine may be seen.

COMPLICATIONS

■ Yersenia enterocoliticaGI infection or sepsis may occur from chronic iron

overload or deferoxamine therapy (both foster the growth of the organism).

Dextromethorphan

Structurally related to levorphanol, a synthetic opioid agonist.

MECHANISM/TOXICITY

■ Antagonizes NMDA receptors and inhibits serotonin reuptake

SYMPTOMS/EXAM

■ Mild to moderate overdose: Agitation, ataxia, nystagmus, visual and audi-

tory hallucinations

■ Severe overdose: Coma and respiratory depression

■ Serotonin syndrome is rare but may occur when ingested with other sero-

tonergic agents.

TREATMENT

■ Supportive and symptomatic therapy

Diphenhydramine

■ Diphenhydramine is a sedating antihistamine medication with anticholin-

ergic, antitussive, antiemetic, and local anesthetic properties.

MECHANISM/TOXICITY

■ Antagonizes histamine-induced responses at H 1 receptors→smooth mus-

cle relaxation.

■ Antagonism of H 1 receptors in the brain →sedation.

■ Antagonism of cholinergic muscarinic receptors →anticholinergic effects.

■ Na++channel blockade (at high doses)

SYMPTOMS/EXAM

■ CNS depression

■ Cholinergic toxidrome

■ Extremely large doses may cause seizures and dysrhythmias.

DIAGNOSIS

■ Based on history and clinical presentation

TREATMENT

■ Supportive and symptomatic therapy

■ Benzodiazepines for agitation or seizures

■ Sodium bicarbonate if wide complex dysrhythmias occur

Iron antidote = deferoxamine.