Toxicology

300 English flashcards in Question-and-Answer style covering key concepts, definitions, mechanisms, clinical features, and antidotes from Module 4 (Toxicology) lecture notes.

What branch of pharmacology studies poisons, their mechanisms, and their treatment?

Toxicology

What is the estimate of potential effects of a poison on human health and the environment called?

Risk assessment

In toxicology, how is a Hazard defined?

The ability of a chemical agent to cause injury in a given situation or setting

In toxicology, how is Risk defined?

The expected frequency of an undesirable effect arising from exposure to a chemical or physical agent

Which Latin phrase by Paracelsus means “the dose makes the poison”?

Sola dosis facit venenum

What term is used for a naturally occurring poison produced by living organisms?

Toxin

What term is used for a man-made or artificial poison?

Toxicant

Name the two major CNS pathophysiologic mechanisms caused by poisons.

CNS stimulation and CNS depression

Severe CNS stimulation may progress to what life-threatening complication?

Seizures that can lead to brain damage

Loss of airway protective reflexes and respiratory drive indicate which pathophysiologic mechanism?

CNS depression

Which mnemonic summarizes muscarinic (parasympathomimetic) poisoning signs?

DUMBELS

In the DUMBELS mnemonic, what does the letter “M” represent?

Miosis or Muscle fasciculations

Which mnemonic summarizes classic sympathomimetic effects?

MATHS

In the MATHS mnemonic, what does “H” stand for?

Hypertension

Name two common cardiovascular effects produced by many poisons.

Cardiac arrhythmias and altered vascular tone (vasodilation or vasoconstriction)

Aspiration of gastric contents can lead to what respiratory consequence?

Bronchospasm or chemical pneumonitis

Interference with oxygen transport and utilization produces which cellular condition?

Cellular hypoxia

Rhabdomyolysis with myoglobinuria may ultimately damage which organ?

The kidneys (renal failure)

Which FDA pregnancy category signifies proven teratogenic risk and is contraindicated in pregnancy?

Category X

Which antibiotic class can cause permanent tooth discoloration in the fetus?

Tetracyclines

Which mood stabilizer is classically associated with Ebstein’s anomaly?

Lithium

Prenatal exposure to which drug caused clear-cell adenocarcinoma of the vagina and cervix?

Diethylstilbestrol (DES)

List three hallmark features of fetal alcohol syndrome.

Facial anomalies, growth retardation, and neurodevelopmental defects

Immediate effects of a poison are seen after what type of exposure?

A single (acute) administration

Are carcinogenic and teratogenic effects usually reversible or irreversible?

Irreversible

Phenol producing a skin burn is an example of which effect type—local, remote, or systemic?

Local effect

Paraquat ingestion producing pulmonary fibrosis represents which effect type?

Remote effect

Which mnemonic lists major causes of high-anion-gap metabolic acidosis?

MUDPHILES

What does the “M” in MUDPHILES stand for?

Methanol

For ingested toxins, what time frame defines an acute exposure?

Less than 24 hours after a single administration

In exposure classification, how long does chronic exposure last?

More than 3 months

Which head and neck position optimizes airway patency during initial resuscitation?

The sniffing position

Neck manipulation should be avoided in airway management under what circumstance?

When a neck (cervical spine) injury is suspected

Give one toxin that can cause flaccid paralysis of ventilatory muscles.

Botulinum toxin (others: neuromuscular blockers)

Which gas binds hemoglobin with high affinity and causes cellular hypoxia?

Carbon monoxide

Name an opioid that can depress the CNS and impair ventilation.

Morphine (any potent opioid)

What is the adult antidote dose for hypoglycemia?

50 mL of 50 % dextrose IV (25 g)

What is the initial naloxone dose for suspected opioid intoxication?

0.2–0.4 mg IV or IM

Which specific antidote reverses benzodiazepine overdose?

Flumazenil

What does the AMPLE mnemonic stand for in the secondary survey?

Allergies, Medications, Past medical history/Pregnancy, Last meal, Events

For dermal chemical exposure, how long should the skin be rinsed with water?

Approximately 30 minutes

Which topical agent is recommended for hydrofluoric acid burns?

Calcium soaks (e.g., calcium gluconate gel or solution)

What immediate step is required for inhalational poisonings?

Remove the patient from the toxic environment and administer oxygen

How long should the eyes be irrigated after a chemical splash?

At least 15 minutes (about 2 L of solution)

What charcoal-to-toxin weight ratio is recommended when giving activated charcoal?

10 : 1

Give one substance poorly adsorbed by activated charcoal.

Iron (others: lithium, alcohols, cyanide, heavy metals)

Which emetic agent is used when other decontamination methods are unavailable?

Syrup of ipecac

Name one contraindication to gastric lavage.

Ingestion of corrosive substances

Why are sodium- or magnesium-containing cathartics contraindicated in renal insufficiency?

Because electrolyte accumulation may worsen renal function

Whole-bowel irrigation uses a solution containing what osmotic agent?

Non-absorbable polyethylene glycol with balanced electrolytes

Which binding resin can be given orally for lithium toxicity?

Sodium polystyrene sulfonate (Kayexalate®)

What type of antidote competes for the same receptor as the poison?

Pharmacologic antidote

Give an example of a physiologic antidote used for anaphylaxis.

Epinephrine

How does sodium thiosulfate act in cyanide poisoning?

It chemically converts cyanide to thiocyanate, a less toxic water-soluble compound

Name the three classic ingredients of the historical “universal antidote.”

Activated charcoal, magnesium oxide, and tannic acid

Which specific antidote is indicated for paracetamol (acetaminophen) overdose?

N-Acetylcysteine (NAC)

Which two drugs are routinely used to treat organophosphate poisoning?

Atropine and pralidoxime

Deferoxamine is the antidote for toxicity from which metal?

Iron

Which cardio-selective beta-blocker treats theophylline or caffeine toxicity?

Esmolol

Which two agents can be used as competitive substrates for alcohol dehydrogenase in methanol poisoning?

Ethanol and fomepizole

Forced alkaline diuresis is most useful for eliminating which class of drugs?

Weak acids

Which IV agent is used to alkalinize the urine?

Sodium bicarbonate

Give two criteria that favor dialyzability of a toxin.

Water solubility and volume of distribution less than 1 L/kg (also low protein binding, MW < 500 Da)

Which extracorporeal technique is only 10–15 % as effective as hemodialysis?

Peritoneal dialysis

Name two toxic alcohols commonly encountered in industry or households.

Methanol and ethylene glycol

What clinical phase of ethylene glycol poisoning occurs 30 minutes to 12 hours post-ingestion?

CNS depression (first stage)

Visual disturbances in methanol poisoning are primarily due to accumulation of which metabolite?

Formic acid (formate)

What drug is a direct alcohol dehydrogenase inhibitor used in methanol poisoning?

Fomepizole

Formaldehyde exposure primarily irritates which body surfaces?

Oral, pharyngeal, and conjunctival mucous membranes

Hydrocarbon toxicity is usually a consequence of what event?

Aspiration into the lungs

Which aromatic hydrocarbon is linked to acute myeloblastic leukemia?

Benzene

Which gas smells like bitter almonds and blocks cytochrome oxidase?

Hydrogen cyanide

Name one natural food source that can release cyanide.

Cassava (others: bitter almonds, lima beans, Prunus seeds)

What is the first drug administered from a cyanide kit?

Amyl nitrite (inhaled) to induce methemoglobinemia

Hydroxocobalamin binds cyanide to form what nontoxic compound?

Cyanocobalamin (vitamin B12)

Hydrogen sulfide has what characteristic odor?

Rotten eggs

Which therapy delivering 100 % oxygen under pressure is useful for cyanide or CO poisoning?

Hyperbaric oxygen therapy

Alkali ingestion causes what type of tissue necrosis?

Liquefactive necrosis

What readily available kitchen item can be given orally for strong acid ingestion?

Egg whites (albumin) to coat the mucosa

Phenol contact initially produces what skin color change?

Blanched (white) discoloration followed by corrosive burns

Which yellow food dye is notorious for anaphylactoid reactions?

Tartrazine (FD&C Yellow No. 5)

A collection of flushing and tachycardia after eating high-MSG food is called what?

Chinese Restaurant Syndrome

What common biochemical mechanism underlies heavy-metal toxicity?

Binding to sulfhydryl (-SH) groups of enzymes, causing inactivation

Which chelating agent is known as British Anti-Lewisite?

Dimercaprol (BAL)

Which oral chelator is a water-soluble derivative of BAL?

Dimercaptosuccinic acid (DMSA, succimer)

What drug of choice chelates ferric iron in iron poisoning?

Deferoxamine

Penicillamine is the first-line chelator for excess of which metal?

Copper (as in Wilson’s disease)

Which chelator displaces calcium as it binds divalent metals such as lead?

Calcium disodium EDTA (CaNa2 EDTA)

Acute arsenic poisoning imparts what odor to the victim’s breath?

Garlic odor

Transverse white lines across the nails caused by chronic arsenic exposure are called what?

Mee’s lines

Lead inhibits which heme-synthesizing enzyme commonly used for diagnosis?

δ-Aminolevulinic acid (ALA) dehydratase

Weakening of wrist and finger extensors from lead exposure is known as what?

Lead palsy

What is the approximate half-life of lead in bone?

About 32 years

Itai-itai disease was traced to chronic poisoning by which metal?

Cadmium

Chronic inorganic mercury poisoning (Mad Hatter’s disease) is characterized by which triad?

Gingivitis, tremors, and neuropsychiatric changes

Pink discoloration of hands and feet from mercury exposure is called what?

Acrodynia

Eating fish high in methylmercury led to what historically famous neurologic disease?

Minamata disease

Children often suffer iron poisoning after ingesting what household item?

Over-the-counter iron tablets or vitamins

Copper deposition in the corneal limbus of Wilson’s disease forms what ring?

Kayser-Fleischer ring

Which air pollutant binds hemoglobin 200× more avidly than oxygen?

Carbon monoxide