Q1 2.4 TOXI LAB

Modern toxicologic management emphasizes treating the patient’s clinical status over:

• Identifying and targeting the specific poison with antidotes

• Immediate gastrointestinal decontamination in all cases

• Empirical administration of supportive care therapies

• Serum toxicology screening prior to treatment

Why was the historical standard treatment for comatose overdose patients (IV D50W, thiamine, naloxone, high-flow oxygen) considered a “shotgun approach”?

• Because it relies on definitive diagnosis before treatment

• Because empirical treatment was given regardless of presenting symptoms or suspected poison

• Because treatment focused exclusively on opioid overdoses

• Because interventions were always administered late

IV thiamine administration in overdose patients primarily prevents:

• Lactic acidosis resulting from thiamine deficiency

• Hepatic injury associated with chronic alcoholism

• Wernicke’s encephalopathy triggered by glucose loading in thiamine-deficient states

• Cerebral edema in overdose patients with electrolyte abnormalities

What is a critical limitation of syrup of ipecac as a gastrointestinal decontamination tool?

• High risk of aspiration, especially in patients with compromised airway reflexes

• Absorption of toxins decreases with induced emesis

• It enhances systemic absorption of poisons due to irritation

• Ineffective on poisons ingested more than 24 hours prior

Whole bowel irrigation (WBI) with polyethylene glycol electrolyte solution (PEG-ELS) is particularly indicated for:

• Rapid gastric emptying prior to charcoal administration

• Ingestion of sustained-release or enteric-coated preparations

• Rapid detoxification of hydrocarbons and corrosives

• Reversal of opioid toxicity by enhanced GI elimination

Activated charcoal is ineffective or contraindicated in poisoning with:

• Tricyclic antidepressants

• Lithium and heavy metals

• Barbiturates

• Aspirin

Which physicochemical property of a poison decreases the efficacy of activated charcoal adsorption?

• High lipid solubility

• Low molecular weight and high water solubility

• High protein binding in plasma

• Presence of multiple aromatic rings

Multiple-dose activated charcoal (MDAC) improves elimination of certain drugs by:

• Blocking intestinal absorption only during first pass

• Interrupting enterohepatic and enteroenteric recirculation

• Increasing renal clearance of metabolites

• Enhancing metabolic transformation in the liver

Ion trapping via urinary alkalinization is MOST effective in facilitating elimination of:

• Weak acids such as salicylates, phenobarbital, and chlorpropamide

• Weak bases such as amphetamines and cocaine

• Heavy metals like arsenic and mercury

• Large polar molecules with poor GI absorption

Naloxone is administered empirically in overdose patients suspected of opioid toxicity because:

• It has a wide therapeutic index and minimal side effects

• It reverses respiratory depression regardless of cause

• Opioid overdose is the most common cause of altered mental status

• It treats all sedative-hypnotic overdoses including benzodiazepines