Repro: Test 2: 20&21. Bridges : Tox Ii & Iii

Front 1

Carbon monoxide produces what effect?

Back 1

anemic hypoxia

has higher affinity for iron than O2

Front 2

2 major places CO effects?

**

Back 2

Heart and CNS

Front 3

why does CO cause syncope?

Back 3

CO stimulates guanylate cyclase
cerebral vasodilation --> syncope

Front 4

CO can have direct cellular tox, where is the key place it does this? how?

Back 4

Myoglobin binding

causes skeletal and CARDIAC MUSCLE tox

Front 5

Tx for CO poisoning?

Back 5

100% O2 (it outcompetes the CO)

Front 6

how many half-lives does it take to reverse a process?

why is hyperbaric O2 arguably a better tx than 100% O2

Back 6

about 5

some studies say that hyperbaric O2 can cut the half-life to CO to 20minutes

where as 100% O2 takes 1 hr

Front 7

Mechanism of CN poisoning?

Back 7

binds to Iron

SHUTS DOWN THE ELECTRON TRANSPORT CHAIN--> Can't make ATP (no ox phos)

Front 8

what enzyme metabolizes CN?

what is the limiting factor in detoxifying CN?

Back 8

Rhodanese

limiting factor: reducing sulfur (thiosulfate)

Front 9

What is the standard tx for CN poisoning?

Back 9

MUST BE IMMEDIATE

Sodium nitrite (IV) followed by sodium thiosulfate (IV)

Nitrite:
promotes formation of methemoglobin (metHb, Fe+3) to detoxify cyanide to cyanmethemoglobin

Thiosulfate:
facilitates enzyme-catalyzed conversion of cyanide to less-toxic thiocyanate

Front 10

what does Hydroxycobalamin tx? How?

Back 10

directly binds up CN and it is filtered/excreted

Front 11

how do organophosphates cause tox?

Back 11

Cholinesterase inhibitors

Toxic levels of ACh accumulation --> DUMBBBELS

Diarrhea, Urination, Miosis, Bronchorrhea, Brochospasm, Bradycardia, Emesis, Lacrimation, Salivation

Front 12

Painful stocking-glove paresthesias is assoc with what toxin?

Back 12

Organophosphate Pesticides

cause delayed neurotoxicity

also seen in chronic arsenic poisoning

Front 13

Tx for organophosphate pesticides?

****

Back 13

Atropine
To block muscarinic effects … give until respiratory secretions are controlled (dry as a bone)

Pralidoxime (2-PAM)
Reactivates acetylcholine esterase … before aging process occurs
Measure RBC cholinesterase activity
If decrease 50%, indicates significant poisoning … should use PAM

**If significant nicotinic or CNS effects … use PAM **

Front 14

MOA of carbamate tox? effects? tx?

Back 14

Inhibits acetylcholinesterase by carbamoylation

Similar effects to organophosphates … but effects less severe … because carbamoylation is rapidly reversible

tx: ATROPINE (PAM is NOT EFFECTIVE, may make things worse)

Front 15

2 unique traits of paraquat

Back 15

Specific to the lungs

KILLS YOU SUPER FAST..death very likely

Front 16

Mech of Paraquat poisoning?

Back 16

Accumulates slowly in lungs by active process (regardless of exposure route)

Single electron reduction produces free radical species that damages lung tissue

Front 17

pt smokes a fat joint and suddenly has GI irriation, with bloody coughing and stools. Somehow he survives but develops respiratory distress...this could lead to fatal pulmonary fibrosis...what poisoned him? Tx?

Back 17

Paraquat

No specific antidote …
Activated charcoal or Fuller’s earth effective if taken in time
Fuller’s earth: claylike earthy material

TRY TO PREVENT ABSORPTION

Front 18

pt overdoses on warfarin...tx?

Back 18

Treat with Vitamin K

Front 19

Methyl bromide causes it major tox where?

Back 19

CNS:
Headaches Visual disturbances Seizures
CNS depression and coma may occur
Pulmonary edema after respiratory exposure

Front 20

how does strychnine cause problems? what does it cause? tx

Back 20

Competitively blocks glycine inhibition of neurons

CNS excitation … severe seizures … death
Opisthotonus
Type of spasm in which the head and heels arch backward in extreme hyperextension and the body forms a reverse bow

FATAL DUE TO RESPIRATORY PARALYSIS
--Support respiration with diazepam

Front 21

All petroleum hydrocarbons produce similar effects including what? if administered how, it will produce the worst effects

Back 21

CNS Depression

aspiration

Front 22

the most serious problems arise when petroleum hydrocarbons are put into the body in what way?

Back 22

if you aspirate it you will have more serious problems

Front 23

want to play a game?

Front 24

how does lead poisoning differ in children and adults

Back 24

in kids it can cross the BBB and cause CNS effects

may cause lowered IQ and behavioral problems
Early signs of toxicity include:
Clumsiness, vertigo, ataxia, headache, restlessness, irritability
Progressive central neuropathy may involve vomiting, seizures, delirium

Front 25

Where does lead initially bind? where does it redistribute and how long does it stay there?

Back 25

Initially binds to hemoglobin in RBCs, remainder goes to soft tissues

Later … redistributes to bone (95%), teeth, and hair … where the t½ is ~25 years!!

Front 26

pt presents with lines of deposits on the gingiva...what toxin is in them?

Back 26

LEAD

Front 27

what is the diagnostic test for lead poisoning?

*

Back 27

Inhibits heme formation
inhibits gamma-aminolevulinic acid dehydratase

elevated ALA in the urine (diagnostic)

but blood lead level is most useful...tells you what action to take

Front 28

ORGANIC lead poisoning leads to what?

Back 28

CNS symptoms

Front 29

tx for lead poisoning?

Back 29

Chelation therapy: EDTA

binds up lead and excretes it in the urine

Front 30

effects of arsenic poisoning

Back 30

GI, resp, nervous, and can uncouple mitochondria (decrease ATP)

Main one is excruciating GI pain (bleed, etc)

Front 31

what is an important sign of chronic arsenic poisoning?

Back 31

pins and needles sensation in stocking & glove distribution

Front 32

Hyperpigmentation
palms and soles
hallmark of chronic exposure of what?

Back 32

Chronic arsenic poisoning

Front 33

Hyperkeratosis
white lines in nails (Mee’s lines) is a classic finding of what?

Back 33

Chronic arsenic poisoning

Front 34

tx for inorganic arsenic poisoning?

Back 34

Lavage

Chelation therapy

Front 35

what happens with arsine GAS poisoning?

***

Back 35

Rapid severe hemolysis

extensive hemolytic anemia --> often fatal

Front 36

2 primary systems affected by mercury?

Back 36

Kidneys

CNS

Front 37

tx for mercury?

Back 37

chelation

Front 38

classic triad of effects of mercury poisoning?

**

Back 38

Neuropsychiatric disorders (erethism: shyness, withdrawal, depression, explosive anger)--MAD HATTER

Tremors

Gingivostomatitis

Front 39

ashen-gray mucous membranes would make you think what?

Back 39

acute inorganic mercury poisoning

Front 40

what is Acrodynia? due to? affects who?

Back 40

Acrodynia (pink disease):

Erythema of extremities
Severe leg cramps, paresthesias, painful pink fingers

Primarily affects young children chronically exposed to mercury

Front 41

what happens in the first phase of iron poisoning?

Back 41

GI damage (necrotizing gastroenteritis)
abdominal pain
vomiting, diarrhea (bloody)
cyanosis, acidosis
CV collapse
death

Front 42

what happens in stage II of iron poisoning?

Back 42

apparent recovery, followed by death

Front 43

tx for iron overdose?

**

Back 43

Chelation with deferoxamine

empty the stomach too

Front 44

EDTA is primarily used to treat what?

Back 44

Lead poisoning

Front 45

Dimercaprol is a chelating agent used to treat what? 3

Back 45

For arsenic, mercury or lead poisoning

Front 46

Succimer is used to treat what? 3, in what type of pt?

***

Back 46

Useful in lead, arsenic or mercury poisoning

in kids!

Front 47

Penicillamine is used for what?

Back 47

copper and mercury poisonings

Wilson's disease

Front 48

Deferoxamine is used to treat what?

Back 48

Iron tox