Lecture 15 / 16: Toxicology Flashcards

Question

Signs of non-opiate related poisoning

Answer 1

Hypotension, bradycardia, coma, respiratory depression, miosis, hyporeflexia, CNS depression

Answer 2

Symptomatic treatment specific antidotes as appropriate (flumazenil - benzo antagonist), IV saline

Answer 3

Concert Conductors Make Music (1st 4) 1. Confusion 2. CNS depression 3. Muscle Twitching-weakness / paralysis 4. Miosis 5. Salivation 6. Lacrimation 7. Urination 8. Defecation SLUD (last 4)

Answer 4

Organophosphate, carbamate insecticides, physostigmine, edrophonium, mushrooms

Answer 5

atropine Pralidoxime (2-PAM) for organophosphates only

Answer 6

toxic syndrome, history, lab tests, poison control center

Answer 7

Non-specific Treatment non-specific chelator, limits drug absorption, not as efficacious if drug is rapidly absorbed

Answer 8

Non-specific Treatment recent ingestion of caustic liquids: not as useful for removal of pills or pill fragments

Answer 9

Used only in rare occasions Exposure < 30 min, ingestion of massive drug dose (100-150 aspirin tablets)

Answer 10

Non specific treatment Non-absorbable polyethylene glycol (PEG-350) Used with large ingestion of drugs poorly absorbed by activated charcoal (Fe, Li)

Answer 11

methyl parathion, VX nerve agent and carbamates Acetylcholine Esterase Inhibitors irreversible—organophosphates (2-PAM can “reverse”) reversible----carbamates

Answer 12

headache, nausea, dizziness cholinergic complaints ----SLUD

Answer 13

extremely toxic---respiratory failure due to diaphragm muscle paralysis, central depression of respiratory centers in CNS and bronchoconstriction

Answer 14

Treatment: ◼ atropine for both carbamates and organophosphates ◼ Pralidoxime (2-PAM) for organophospate

Answer 15

Cholinergic Colorless, odorless fast-acting chemical weapon

Answer 16

◼ windshield washer solvent for cars ◼ mixed solvents (paint removers) ◼ hand sanitizer during COVID pandemic

Answer 17

CNS depression like ethanol

Answer 18

metabolized to formaldehyde by alcohol dehydrogenase and formate by (aldehyde dehdydrogenase) – blindness, metabolic acidosis

Answer 19

◼Metabolic acidosis with Na bicarbonate IV ◼Folic acid B vit. complex, converts formate to CO2 and H2O ADH inhibitors ◼Fomepizole (Antizol®) ◼Ethanol

Answer 20

found in auto antifreeze (95%)--other industrial solvents

Answer 21

◼ CNS depression like ethanol ◼ metabolized ---eventually to oxalic acid ◼** hypocalcemic tetany and oxalicaciduria --crystals **

Answer 22

◼Hypocalcemia treat with Ca2+ IV ◼Pyridoxine, folate, thiamine – cofactors for eth. glyc. metabolism ADH inhibitors ◼ Fomepizole (Antizol ®) ◼ Ethanol

Answer 23

consuming contaminated food prepared with lead cooking utensils, lead-soldered food cans ingestion of lead paint chips and inhalation of lead dust are major lead sources. 10-20% of exposure due to contaminated drinking water (lead pipes) Toys made in other countries have lead contaminated paint Lead in gasoline Occupational exposure

Answer 24

Blood - hypochromic microcytic anemia PNS - weak wrist and ankle extensor muscles CNS - lead encephalopathy w/ delirium, hallucinations and convulsions - can be fatal

Answer 25

GI- more common in long term exposures; colic loss of appetite Kidney - increased uric acid (gout) Reproductive - stillbirths in women; altered sperm

Answer 26

Unknown, possible molecular mimicry occurs and Pb replaces Ca, Zn, Mg normally found in enzymes, proteins, bone mineral, etc… Inhibits hemoglobin synthesis - resulting in a build up of hemoglobin precursors in red blood cells

Answer 27

Find lead source and remove patient For severe cases (≥ 45 µg/dl in children, ≥ 50 µg/dl in adults), metal chelators are given (succimer is first line drug) EDTA is second line drug Dexamethasome is given for cerebral edema

Answer 28

* Children absorb 40% of ingested lead, adults 10% * Pb deteriorates blood brain barrier, more so in children who may not have fully formed BBB * Childhood Pb exposure is associated with lower IQ, ADHD, aggressive behavior and juvenile delinquency

Answer 29

several forms exist with varying degree of toxicity elemental forms are the most toxic (e.g. trivalent or pentavalent). Organic arsenicals are considered least toxic and occur naturally in seafood.

Answer 30

◼ contaminant of coal, metal ores, rural/municipal water supplies in US but especially in Bangladesh ◼ industrial workers in semiconductor industry at risk

Answer 31

◼ violent nausea, laryngitis, bronchitis, hemorrhagic gastroenteritis (rice water diarrhea) ◼ garlic odor on breath ◼ capillary damage--dehydration, shock, death ◼ if patient survives-- sensory neuropathy follows

Answer 32

Chronic intoxication:—more common and insidious ◼ can be few symptoms until irreversible injury ◼ dermal manifestations ---hyperkeratosis, exfoliative dermatitis, vesicular lesions on feet, peripheral neuropathy ◼ cutaneous vasodilation ---”Milk and Roses” complexion ◼bone marrow depression, fatty liver degeneration---death ◼Increased risk of cancers

Answer 33

High affinity for –SH groups on proteins Likely causes severe oxidative stress and disrupt protein function by binding to –SH containing amino acids

Answer 34

◼The metal chelator Dimercaprol (BAL) – British Antilewisite given IM

Answer 35

Only occurs in miners; gas formed when acid touches arsenic metal

Answer 36

◼ produces rapid hemolysis and death ◼ low dose produces partially reversible kidney damage

Answer 37

◼ NO Antidote----supportive therapy only

Answer 38

several forms of mercury exist with varying degrees of toxicity. organic forms are more toxic, specifically methylmercury Inorganic and elemental forms of mercury tend to be poorly absorbed. Methylmercury is highly absorbed from GI tract and readily passes blood brain barrier

Answer 39

◼ Hgo (metallic/elemental mercury) metal in dental labs, old thermometers, gold mining ◼ HgCl2, Hg2Cl2 (inorganic salts) used as preservatives, insecticides ◼ HgNO3 in making felt hats (Mad Hatter’s Disease 1800’s) ◼ Methlymercury –** consumption of contaminated fish and grain fungicide**; ethylmercury – thimerosal an antibacterial antifungal agent in multi-dose vaccine vials

Answer 40

All irreversible: * Loss of balance * ataxia * sensory defects * loss of visual field * deafness * dysarthria

Answer 41

Unknown, shown to increase intracellular calcium and bind to metallothionein

Answer 42

Consumption of predatory fish (swordfish, shark) should be limited to one serving per week Women who are nursing or pregnant need to avoid eating predatory fish Canned tuna is considered safe however the MeHg levels depend on many variables

Answer 43

Chelators bind metals → excreted from body Only used in patients with severely elevated metal levels or toxicity Chronic metal accumulation occurs over a life time, can accumulate significant amounts of metal stored in bone and other tissue. Chelation therapy only reduces readily accessible pool of metal After therapy, blood metal levels can rebound

Answer 44

1. Metal Chelator 2. Given IV or IM for severe lead poisoning 3. Toxic to kidney at high dose

Answer 45

Chills, fever, nausea, vomiting, allergies

Answer 46

1. First orally effective chelator 2. More rapidly effective than EDTA for lead 3. GI distress, rash, diarrhea, increase in serum transaminases 4. Studies suggest it may also be useful for arsenic and mercury ---Important chelator

Answer 47

Colorless, odorless, tasteless, nonirritating, ubiquitous Sources: any burning or combustion process will generate CO

Answer 48

organs with greatest O2 demand will show signs of exposure first headache, dizziness and increased heart rate

Answer 49

* out competes oxygen binding to hemoglobin, 220 greater affinity than oxygen * when bound to one of the four oxygen binding sites on hemoglobin forms carboxyhemoglobin * Carboxyhemoglobin reduces the ability of oxygen to dissociate from hemoglobin and be delivered to the deep tissues needing oxygen.

Answer 50

remove from CO, then hyperbaric O2

Answer 51

possible cardiovascular problems

Answer 52

present in smoke (burning of plastics, wool), industrial exposure (plastics and metal plating), chemical warfare agent

Answer 53

“bitter almond” breath, headache, nausea, tachypnea, apnea, loss of consciousness, seizures and coma

Answer 54

binds to cytochrome oxidase resulting in inhibition of electron transport chain and the ability of the cell to utilize oxygen in producing ATP

Answer 55

2 ways to Treat: * Cyanokit is first line with a 2- step method used as a backup * Cyanide + Hydroxocobalamin (Cyanokit®) → cyanocobalamin (vitamin B12) * Older method 2 steps: can not be given with CO inhalation 1. Na nitrite → methemoglobin + cyanide → cyanomethemoglobin 2. cyanomethemoglobin + Na thiosulfate → thiocynate (urine)

Answer 56

Flame retardants, plasticizers, insulating material in electric transformers Recent finding that farm raised Salmon had higher PCB content than wild Salmon Environmentally stable, still present even though use curtailed in 1970s

Answer 57

dermal acne-like eruptions called chloracne, nausea, headache, vomiting