!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.1//EN” “http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd”>

Toxicology, Bioterrorism, and Chemical Warfare Agents

Alcohols, ethylene glycol

Antidotes for common drugs

Bioterrorism or chemical warfare agents

Heavy metals

Poisonings of unknown cause

Poisoning syndromes

Toxic gases

Questions

479. A patient develops status epilepticus from an unknown poisoning. Which of the following is the most appropriate first IV drug to give?

a. Carbamazepine

b. Lorazepam

c. Phenobarbital

d. Phenytoin

e. Valproic acid

480. A firefighter who is trying to extinguish a car fire has a leak in his protective air mask. He develops cyanide poisoning from the combustion of plastic. Aside from rendering symptomatic, supportive care, which might be administered to combat the cyanide poisoning?

a. Ammonium chloride

b. Deferoxamine

c. Dimercaprol (BAL; British anti-lewisite)

d. Mannitol

e. Pralidoxime

f. Sodium thiosulfate

481. A 28-year-old male patient is transported to the emergency department after a massive exposure to carbon tetrachloride (CCl₄), a solvent used at his work. Which one of the following best describes a characteristic of poisoning with this toxicant, or its clinical management?

a. Causes a slow death due to bone marrow suppression

b. Causes widespread ATP depletion by uncoupling oxidative phosphorylation

c. Metabolized to free radicals (trichloro radicals) that are directly cytotoxic to liver and kidney cells

d. N-Acetylcysteine effectively scavenges carbon tetrachloride’s cytotoxic metabolite

e. Toxic consequences reduced or prevented by administration of methylene blue

482. A patient who has been on long-term therapy with a drug develops a lupus-like syndrome in response to it. With which drug is this response, probably mediated by an autoimmune reaction, most likely to occur?

a. Dioxin

b. Hydralazine

c. Organic mercury

d. Primaquine

e. Tricyclic antidepressants (eg, amitriptyline)

483. A patient presents in the emergency department with a drug overdose. Among other things, the physician correctly orders IV infusion of sodium bicarbonate to alkalinize the urine, which increases the toxin’s elimination through pH-dependent inhibition of its tubular reabsorption, and helps correct the combined metabolic and respiratory acidosis the toxin caused. Which one of the following drugs most likely caused the toxicity?

a. Amphetamine

b. Aspirin (acetylsalicylic acid)

c. Cocaine

d. Morphine

e. Phencyclidine (PCP)

484. A patient has taken a potentially lethal dose of acetaminophen. The emergency department team begins administering repeated doses of N-acetylcysteine, which can be a lifesaving antidote in many such cases. What is the main mechanism by which this antidote exerts its beneficial effects?

a. Alkalinizes the urine to facilitate acetaminophen excretion

b. Causes metabolic acidosis to counteract metabolic alkalosis caused by a toxic acetaminophen metabolite

c. Inhibits P450 enzymes, thereby inhibiting formation of acetaminophen’s toxic metabolite

d. Inhibits synthesis of superoxide anion radical and hydrogen peroxide

e. Is rich in sulfhydryl (–SH) groups that react with and inactivate the toxic acetaminophen metabolite, sparing hepatocytes from attack by the metabolite

485. Your patient developed acute poisoning as a result of inhaling cyanide gas in an industrial accident. In addition to providing symptomatic, supportive care, and other appropriate interventions, administering which one of the following would be most likely to be effective as an adjunctive drug, in treating the cyanide poisoning?

a. Ammonium chloride

b. Deferoxamine

c. Dimercaprol (BAL; British anti-Lewisite)

d. N-acetylcysteine

e. Pralidoxime

f. Sodium thiosulfate

486. A 5-year-old boy consumed a liquid from a container in the family garage. He presents with central nervous system (CNS) depression, obtunded reflexes, and ventilatory depression. A blood sample indicates profound metabolic acidosis and an anion gap. A check of the urine reveals crystals that are presumed to be oxalate. What is the most likely cause of the poisoning?

a. A halogenated hydrocarbon from a can of spray paint

b. An insecticide

c. Ethylene glycol

d. Gasoline

e. Paint thinner

487. A farm worker in California is brought emergently, and declared dead on arrival, to a local emergency department. He had been exposed to an agricultural toxin. A coworker, who was not poisoned but was nearby right after the time of exposure, said, “He just started shaking bad, collapsed, and immediately stopped breathing. I didn’t see anything else happen. He looked perfectly normal one minute, then he was just dead.” What was the most likely cause of this man’s death?

a. Cholinesterase inhibitor insecticide, sprayed by a crop duster airplane

b. Kerosene from a barn heater, ingested

c. Long-term and cumulative cutaneous exposure to arsenic, today’s exposure proving rapidly fatal

d. Petroleum distillates used to clean grease off farm machinery, inhaled

e. Strychnine, ingested

Questions 488 to 489

Here is an excerpt from newspaper article entitled Weed Users Chase High all the Way to the Hospital. Use it to answer the next two questions, and note that the “weed” referred to does not include marijuana or any other plants that contain tetrahydrocannabinol or an opioid.

“Teenagers seeking a hallucinogenic high from the seeds of a poisonous weed that now is in bloom are landing in hospitals across the country, police and health officials say… “Lunatic, crazy kids,” says Dodge County, Wis., Sheriff Todd Nehls, whose deputies picked up three hallucinating teenagers in October….

“Poison centers last year recorded 975 incidents involving plants such as [the] weed…” according to the American Association of Poison Control Centers’ annual report.

“[The weed has]… pods that contain seeds that when eaten or brewed in a tea can cause severe hallucinations [delirium] and other reactions, including dry mouth, overheating [fever], agitation, [and] urinary retention… Some cannot urinate and need to have a catheter inserted… [Severe] overdoses can lead to seizures, coma, or death… Most people hospitalized after eating [the] weed have hallucinations that make them so erratic they are a danger to themselves…”

a. Acetylcholine

b. Amphetamine

c. Belladonna alkaloids

d. Bethanechol

e. Cocaine

f. Cyanide

g. Fluoxetine

h. Neostigmine

i. Phencyclidine (PCP)

j. Physostigmine

k. Strychnine

488. Which drug listed above causes signs and symptoms that are most similar to—indeed, virtually identical to—those described in the scenario?

489. Which drug would be most rational and most effective for treating the overdose, assuming the overdose is severe enough to warrant drug therapy?

490. A mother calls to report that her 6-year-old child appears to have swallowed a large amount of an over-the-counter sleep aid about 5 hours ago. The product contained only one active drug, and knowing your drugs you suspect the poisoning is due to diphenhydramine. Assuming your reasoned guess about the cause of poisoning was correct, which of the following signs or symptoms would you expect to find, upon physical exam, to confirm your hunch?

a. Fever; clear lungs; absence of bowel sounds; urinary retention, dry, flushed skin; mydriasis and photophobia; bizarre behavior

b. Bradycardia and profuse diarrhea

c. Miosis with little/no papillary response to bright lights; spontaneous micturition; lack of response to painful stimuli

d. Hypothermia; bounding pulse; hypertension

e. Skeletal muscle weakness or paralysis; profound hypermotility of gut and bladder smooth muscle; bronchospasm

491. A 3-year-old girl ingests 30 tablets of aspirin, 325 mg each. We’ve gotten her to the emergency department within 30 minutes of the poisoning. Which one of the following drugs would be the most rational and hopefully effective to administer as part of the initial treatment plan for what otherwise could have a fatal outcome?

a. Activated charcoal

b. Deferoxamine

c. Dimercaprol

d. N-Acetylcysteine

e. Penicillamine

492. A 50-year-old man has been consuming large amounts of ethanol on an almost daily basis for many years. One day, unable to find any ethanol, he ingests a large amount of methanol (wood alcohol) that he had bought for his camp lantern. Which of the following is the most likely consequence of his methanol poisoning?

a. Atrioventricular conduction defect (block)

b. Blindness

c. Bronchospasm

d. Delirium tremens

e. Metabolic alkalosis

493. A 15-year-old boy attempts suicide with a liquid that he found in his parents’ greenhouse. His dad used it to get rid of “varmints” around the yard. The toxin causes intense abdominal pain, skeletal muscle cramps, projectile vomiting, and severe diarrhea that leads to fluid and electrolyte imbalances, hypotension, and difficulty swallowing. On examination he is found to be volume depleted and is showing signs of a reduced level of consciousness. His breath smells “metallic.” Which of the following probably accounts for these symptoms?

a. Arsenic

b. Cadmium

c. Iron

d. Lead

e. Zinc

494. A 22-year-old is brought to the emergency department by a friend. They had been at a bar for about an hour, and then the patient suddenly became drowsy but was still conscious. She fell and cut her head, and has little difficulty feeling the pain from the trauma. Her ventilatory rate and depth are depressed, but not to a worrisome degree. Her patellar reflexes are blunted and she is ataxic. She responds slowly to questions but is unable to recall anything that happened after arriving at the bar and sipping her first (and last) adult beverage. Her friend stated that she had only one Cosmopolitan and hadn’t been drinking before they went out. With what was this patient’s drink most likely “spiked?”

a. A barbiturate

b. A benzodiazepine

c. An opioid

d. Chloral hydrate

e. Cocaine

f. Pure (grain) alcohol

495. Let’s assume the profoundly CNS-depressed patient in the previous question indeed was overdosed with a benzodiazepine. Which drug is most likely to be effective, indeed would be a preferred pharmacologic antidote, if that were the case?

a. Amphetamine

b. Flumazenil

c. Methylphenidate

d. Naltrexone

e. Physostigmine

496. Recent occupational health studies in several heavily populated urban areas have revealed an astonishingly large number of homes that have lead-based paint and children living in them. However, a number of environmental poisons that could lead to acute or chronic poisoning have also been found there. Which signs and symptoms would be consistent with chronic exposure to toxic levels of inorganic lead?

a. Anorexia and weight loss; weakness, especially of extensor muscles (eg, wrist drop); recurrent abdominal pain

b. Gingivitis, discolored gums, loosened teeth, or stomatitis; tremor of the extremities; swollen parotid or other salivary glands

c. Hallucinations, insomnia, headache, generalized CNS irritability

d. Hyperventilation in response to metabolic acidosis; hypotension; abdominal pain, diarrhea, brown or bloody vomitus; pallor or cyanosis

e. Severe, watery diarrhea; garlicky or metallic breath; encephalopathy, hypovolemia and hypotension

497. Lab tests conducted by the local health department are positive for chronic lead exposure in a child. Lead levels are significantly elevated, but symptoms fortunately are mild and not at all imminently life-threatening. What is the most appropriate antidote for reducing the child’s body load of lead?

a. Ca-Na₂-EDTA

b. Deferoxamine

c. Dimercaprol

d. N-Acetylcysteine

e. Penicillamine

f. Succimer

498. Not long ago, several patients (and a rather shady health care “provider” who is now incarcerated) seeking “relief” from facial wrinkles nearly died because they received injections of botulinum toxin that was improperly obtained and inadequately diluted. Which is a correct characteristic, finding, or mechanism associated with this toxin?

a. Complete failure of all cholinergic neurotransmission

b. Favorable response to administration of pralidoxime

c. Impairment of parasympathetic, but not sympathetic, nervous system activation

d. Massive overstimulation of all structures having muscarinic cholinergic receptors

e. Selective paralysis of skeletal muscle

499. A terrorist drops a vial of “nerve gas” into a crowded subway at rush hour. The patients are brought to the nearest emergency centers and are given atropine. Which effect of the nerve gas will persist after giving the atropine?

a. Bradycardia

b. Bronchospasm

c. Excessive lacrimal, mucus, sweat, and salivary secretions

d. GI hypermotility, fluid and electrolyte loss from profuse diarrhea

e. Skeletal muscle hyperfunction or paralysis

500. A neighbor calls you for advice and help. She knows you are not a veterinary student, but since you’re going to be a physician soon she figures you know everything. Her pet puppy, Pookie, a Pekingese, has eaten a large amount of rodent (rat and mouse) poison. She’s panicked and pleads to know if the precious pooch is poisoned. The rodenticide indeed contains a powerful poison intended to kill rats and mice, but it can do the same to any other animals that have ingested it too, including humans. What is the most likely toxic ingredient in these rodenticides, and probably will cause poor Pookie pronounced problems?

a. Amphetamine-cocaine combination

b. Morphine

c. Succinylcholine

d. Vecuronium (or a similar neuromuscular blocker)

e. Warfarin

Stay updated, free articles. Join our Telegram channel

Join