Chelation therapy

Question 1

What do heavy metals bind in the body

Answer 1

sulfhydryl groups in various organs and on enzymes

Question 2

In acute toxic metal exposure, what is the first usual sign

Answer 2

usually start with GI symptoms

Question 3

What is a typical peripheral neuropathy of acute toxic metal exposure?

Answer 3

“stocking glove”

Question 4

In Chronic toxic metal exposure, what is usually the most obvious symptom?

Answer 4

CNS and PNS symptoms

Question 5

What is the exception to the usual CNS/PNS symptoms in chronic exposure rule

Answer 5

Lead - chronically can have GI - “Lead colic”

Question 6

If someone is a taxodermist what heavy metal poisoning can they present with?

Answer 6

mercury poisoning

Question 7

Lead paint is a major concern for what group of people

Answer 7

wittle babes

Question 8

What are some clue signs of arsenic poisoning

Answer 8

• rice water diarrhea
• long QT
• rashes
• carcinomas

Question 9

What is the usual presentation of chronic thallium poisoning

Answer 9

painful peripheral neuropathy and allopecia

Question 10

What is the usual presentation of chronic mercury poisoning?

Answer 10

crazZzyYy mad hatters disease

Question 11

When would you perform GI decontamination on a metal poisoned patient?

Answer 11

only in the acute setting

Question 12

Which ligans are better for lead, mercury, and calcium: S, N, or O?

Answer 12

Lead and mercury: S and N

Calcium: O

Question 13

Name some characteristics of the ideal chelator

Answer 13

Vd > Vd of chelate
high water solubility - want to pee out
resistant to biotransformation
ability to reach storage location
forms nontoxic complexes
stable at physio pH
low affinity for trace element

Question 14

Dimercaprol or BAL is used for what metal poisonings?

Answer 14

arsenic, lead, mercury

Question 15

Why is it of concern that BAL is made with peanut oil?

Answer 15

allergies and can only be given IM -painful

Question 16

What is a precaution you must take when you give someone BAL?

Answer 16

you must alkalinize the urine to prevent renal toxicity

Question 17

Succimer is used orally in the US to treat what metal poisonings?

Answer 17

cadmium, lead, mercury

Question 18

CaNa2EDTA is used when?

Answer 18

very high lead poisoning - encephalopathy in combo with BAL

Question 19

If Na2EDTA is used instead of its actual sister drug what can happen

Answer 19

hypocalcemia

Question 20

What is prussian blue used for?

Answer 20

cesium and thallium poisoning

Question 21

Why is prussian blue special

Answer 21

not absorbed after oral dosing

Question 22

Which chelators can cause an elevation in LFTs?

Answer 22

Succimer and CaNa2EDTA

Question 23

What symptom in iron poisoning is indicative of morbidity?

Answer 23

vomiting

Question 24

Which type of iron causes toxicity

Answer 24

freeeeeeeeee

Question 25

Iron has many direct corrosive effects that destroy the GI mucosa, but what action do we really care about:?

Answer 25

it uncouples oxphosph

Question 26

How does iron uncoupling oxphosph lead to metabolic acidosis

Answer 26

hypoperfusion leads to generation of lactic acid

Question 27

What are the 5 phases of iron poisoning?

Answer 27

1. first 6 hours - vomiting
2. 6-12 hours - metabolic acidosis, anion gap
3. 12-24 hours - hypotensive, tachy
4. 2-3 days - hepatotoxicity, renal failure, ARDs
5. 2-8 wks - gastric outlet obstruction

Question 28

What is the chelator for iron poisoning?

Answer 28

deferoxamine

Question 29

What are some s/e of deferoxamine?

Answer 29

hypotension
anaphylactoid
yersinia enterocolitis
acute lung injury