Medical Toxicology 3: Radiation, Animal Venoms, and Environmental

What substance damages DNA, RNA, lipids, proteins, and organelles via indirect damage through free radical formation and oxidative stress?

Ionizing radiation

What is the treatment for acute radiation syndrome, caused by high dose short duration exposure and having a prodrome followed by triad of GI (N/V), hematologic (aplastic anemia/pancytopenia), and neuro (dizziness/headache/loss of consciousness) symptoms?

Decontaminate and supportive

What drug should be given stat post radiation exposure to protect the thyroid by blocking absorption of radioactive iodine?

Potassium iodide (KI)

What is the term that refers to dividing a larger dose of radiation into smaller pieces to allow time for cell recover and less death?

Fractionation of dose (radiotherapy)

What is the supportive care given to patients with radiation toxicity?

Antibiotics and filgrastim (C-SF)

What drug chelates radioactive cesium and thallium?

Prussian blue

What drug chelates radioactive plutonium, americium, and curium?

DTPA

What term refers to an animal that is toxic when absorbed?

Poisonous

1 multiple choice option

What term refers to an animal that is toxic when it injects a substance into your body?

Venomous

1 multiple choice option

Which animal blocks K, Na, and Ca channels leading to impaired depolarization and action potential firing?

Scorpion

3 multiple choice options

What is the venom used by the black widow spider?

alpha-latratoxin

Which animal toxin activates Ca channels causing exocytosis of neurosecretory cells leading to neurotoxicity characterized by cramps/pain, N/V, and trouble breathing?

alpha-latratoxin

What is the treatment for a black widow bite caused by alpha-latrotoxin?

Analgesic, benzodiazepine, and antivenom (in high risk)

What is the dermonecrotic venom used by the brown recluse?

Sphingomyelinase D

What is the treatment for systemic anaphylaxis from a bee sting, characterized by flushing, urticaria, brochospasm, hypovolemia, vasodilation, and N/V due to a massive histamine release?

ABCD and epinephrine

What is the toxin used by snakes that has neurotoxic, anticoagulation, necrotic, and rhabdomyolitic effects?

Phospholipase A2

What is the treatment after supportive care for a significant rattlesnake bite, characterized by hypotension and shock?

CroFab antivenom and prophylactic epinephrine

What is the most common major air pollutant?

Carbon monoxide (CO)

What toxin competes with O2 for binding to hemoglobin and has an affinity >200x that of O2 leading to tissue hypoxia?

Carbon monoxide (CO)

Which drug is associated with using non-electric devices and vehicles in poorly ventilated areas, and has the effects of headache, confusion, decreased visual acuity, and tachycardia followed by collapse, all of which are masked by alcohol?

Carbon monoxide (CO)

What is the treatment for CO toxicity?

100% O2

What toxin is a mucous membrane irritant that leads to conjunctival and bronchial irritation of the eyes, nose, and throat leading to bronchial constriction and excessive secretions?

Sulfur Dioxide (SO2)

What toxin is a deep lung irritant that damages the alveoli type 1 cells leading to bronchiolitis obliterans (popcorn lung) which has symptoms similar to COPD?

Nitrogen Dioxide (NO2)

What toxin is released during the burning of fossil fuels that causes lung irritation and may form free radicals?

Ozone (O3)

What is the treatment for ozone (O3) toxicity?

Inhaled corticosteroid and oxygen

What toxin causes dermatitis and chloracne?

Dioxin (TCDD)

What toxin that was commonly used in manufacturing/building induces chromosomal mutations leading to fibrotic lung disorder, lung cancer, and mesothelioma?

Asbestos

What toxins mimic divalent and monovalent cations used by the body, are highly reactive and bind to sulfhydryl groups/lipid constituents leading to altered function, and cause free radical reactions leading to oxidative stress?

Metals

What toxin is a class 1 known human carcinogen by the IARC, commonly found in car batteries and paints that leads to headache, fever, V/D, and pneumonitis?

Cadmium

What is the treatment for inhaled cadmium toxicity?

Fresh air or inhaled high dose corticosteroid if severe

What is the treatment for ingested cadmium toxicity?

Vomiting/gastric lavage and charcoal

What is NOT recommended for ingested cadmium toxicity due to effects causing redistribution of cadmium to the kidneys where they will cause kidney damage?

Dimercaprol

What toxin is a class 1 known human carcinogen by the IARC that is associated with dentists and causes pulmonary fibrosis when inhaled over a period of time?

Beryllium (BE)

What is the treatment for beryllium toxicity?

Corticosteroids

What toxins interfere with the function of biological cations, generate oxidative stress, inhibit enzymes, and alter gene transcription?

Heavy metals

What toxin has no safe levels and serves no useful purpose in the body, leading to growth and intellectual retardation in children?

Lead

What is the treatment for lead toxicity?

Succimer, EDTA, and calcium

What toxin is a known carcinogen that causes severe GI discomfort, vomiting, and rice-water stools?

Arsenic

What is the treatment for arsenic?

Dimercaprol

What toxin has a unique form of toxicity leading to massive hemolytic anemia, renal failure, jaundice, hematuria, and severe abdominal pain with no treatment other than dialysis for renal failure?

Arsine gas (AsH3)

What toxin interacts with sulfhydryl groups, leading to enzyme inhibition and altered cell membranes, characterized by acute effects such as angina, SOB, N/V, kidney damage, gastroenteritis, and CNS damage when inhaled, but also severe renal failure when ingested?

Mercury

What is the treatment for ACUTE mercury toxicity?

Succimer or dimercaprol

What toxin causes behavioral and personality changes such as extreme shyness, excitability, loss of memory, and insomnia from chronic exposure (mad hatter syndrome)?

Mercury

What is the treatment for CHRONIC mercury toxicity?

Succimer

What is the treatment Iron (Fe) toxicity, characterized by vomiting and GI bleeding in small children that have ingested ferrous sulfate tablets?

Deferoximine

What chelation drug is a bidentate chelator that forms 2 bonds with metal and can be clinically used to treat acute arsenic and mercury poisoning as well as lead poisoning when combined with EDTA?

Dimercaprol

What chelation drug can be clinically used for lead, arsenic, and mercury toxicity if used within hours of exposure?

Succimer

What chelation drug is an alternate to succimer in lead poisoning and can be used to treat severe acute mercury and arsenic poisoning?

Unithiol

What chelation drug can be used to treat copper poisoning and Wilson's disease and is adjunctive in gold, arsenic, and lead poisoning??

Penicillamine

What chelation drug is clinically used in lead poisoning but can cause nephrotoxicity?

EDTA

What chelation drug can be used to treat iron overload and acute iron poisoning?

Deferoxamine and deferasirox

What toxin is a rodenticide that inhibits aconitase of the krebs cycle and depletes ATP?

Fluoroacetic acid

What toxin is a rodenticide that inhibits synthesis of vitamin K dependent clotting factors leading to nosebleed and bruising?

Coumarin/Warfarin

What is the treatment for coumarin/warfarin overdose?

Vitamin K

What herbicides were called "Agent Orange" and are linked to cancer, birth defects, and non-Hodgkin's lymphoma?

Chlorophenoxy acids

What herbicide that may increase the risk of non-Hodgkin's lymphoma was the primary ingredient in Roundup?

Glyphosphate

What herbicide often used to kill weeds on the sides of highways and farms forms damaging free radicals, and causes nausea, hematemesis, bloody stools, and pulmonary impairment/fibrosis when ingested?

Paraquat

What is the treatment for paraquat toxicity?

Activated charcoal and Acetylcysteine/salicylate