CHAPT 57: HEAVY METALS

Question 1

The
toxicity profiles of metals differ, but most of their effects appear
to result from interaction with _______ groups of enzymesand regulatory proteins.

Answer 1

sulfhydryl

Question 2

organic compounds with 2 or more electronegative groups that form stable bonds with cationic metal atoms.

Answer 2

Chelators

Question 3

Chelators function as chemical _________ (agonist or antagonist)

Answer 3

antagonists

Question 4

used as antidotes in the treatment of heavy metal poisoning

Answer 4

Chelators

Question 5

Heavy metal that serves no useful purpose in the body and can damage the hematopoietic tissues, liver, nervous system, kidneys, gastrointestinal tract, and reproductive system

Answer 5

Lead

Question 6

a major environmental hazard because it is present in the air and water throughout the world

Answer 6

Lead

Question 7

The primary signs of this syndrome are acute abdominal colic and central nervous system (CNS) changes, including, particularly in children, acute encephalopathy.

Answer 7

Acute lead poisoning

Question 8

also known as plumbism

Answer 8

Chronic lead poisoning

Question 9

Signs include peripheral neuropathy (wrist-drop is characteristic), anorexia, anemia, tremor, weight loss, and gastrointestinal symptoms.

Answer 9

Chronic lead poisoning

Question 10

Chronic lead poisoning is treated via chelation therapy with ____ ________

Answer 10

oral succimer

Question 11

presents as growth retardation, neurocognitive deficits, and developmental delay in children

Answer 11

Chronic lead poisoning

Question 12

High dietary
________ impedes lead absorption.

Answer 12

calcium

Question 13

poisoning due to tetraethyl lead or tetramethyl lead contained in “antiknock” gasoline additives

Answer 13

Organic lead poisoning

Question 14

widely used in industrial processes and is also present in certain soils and released during the burning of coal

Answer 14

Arsenic

Question 15

results in severe gastrointestinal discomfort, vomiting, “rice-water” stools, and capillary damage with dehydration and shock

Answer 15

Acute arsenic poisoning

Question 16

In acute arsenic poisoning, a ______,_______ odor may be detected in the breath and the stools.

Answer 16

sweet; garlicky

Question 17

Acute arsenic poisoning is treated via chelation therapy with ________

Answer 17

dimercaprol

Question 18

causes skin changes, hair loss, bone marrow depression and anemia, and chronic nausea and gastrointestinal disturbances

Answer 18

Chronic arsenic poisoning

Question 19

an occupational hazard
formed during the refinement and processing of certain metals and
is used in the semiconductor industry

Answer 19

Arsine gas

Question 20

causes a unique form of toxicity characterized by massive hemolysis

Answer 20

Arsine

Question 21

used as seed dressings and fungicides

Answer 21

Organic mercury

Question 22

used in materials in dental laboratories and in the manufacture of wood preservatives, insecticides, and batteries

Answer 22

Inorganic mercury

Question 23

usually occurs through inhalation of inorganic elemental mercury

Answer 23

Acute mercury poisoning

Question 24

Chronic mercury intoxication has
been treated with _______ and _______, but their efficacy has not
been established.

Answer 24

succimer; unithiol

Question 25

_________ may redistribute mercury to the CNS and should not be used in chronic exposure to elemental mercury.

Answer 25

Dimercaprol

Question 26

first recognized in connection with an epidemic of neurologic and psychiatric disease in the village of Minamata, Japan

Answer 26

Organic mercury poisoning

Question 27

occurs frequently in small children

Answer 27

Acute iron poisoning

Question 28

the chelating agent of choice for Iron poisioning

Answer 28

Deferoxamine

Question 29

Chronic excessive intake of iron can lead to

Answer 29

hemosiderosis or hemochromatosis

Question 30

is a bidentate chelator; that is, a chelator that forms 2 bonds with the metal ion, preventing the metal’s binding to tissue proteins and permitting its rapid excretion

Answer 30

Dimercaprol (BAL)

Question 31

acute arsenic and mercury poisoning and, in combination with EDTA, for lead poisoning.

Answer 31

Dimercaprol

Question 32

Dimercaprol is a/an _____ liquid that must be given parenterally.

Answer 32

oily

Question 33

Long-term use of Dimercaprol is associated with __________ and increased prothrombin time.

Answer 33

thrombocytopenia

Question 34

is a water-soluble bidentate congener of dimercaprol

Answer 34

Succimer (DMSA)

Question 35

used for the oral treatment of lead toxicity in children and adults.

Answer 35

Succimer

Question 36

Succimer is also effective in ______ and _________ poisoning, if given within a few hours of exposure.

Answer 36

arsenic; mercury

Question 37

A water-soluble derivative of dimercaprol

Answer 37

Unithiol

Question 38

MOA of Unithiol

Answer 38

Orally or Intravenously

Question 39

causes a low incidence of dermatological reactions, usually mild

Answer 39

Unithiol

Question 40

a derivative of penicillin, another bidentate chelator

Answer 40

Penicillamine

Question 41

The major uses of penicillamine

Answer 41

treatment of copper poisoning and Wilson's disease

Question 42

an efficient polydentate chelator of many divalent cations, including calcium, and trivalent cations

Answer 42

Ethylenediaminetetraacetic Acid (EDTA; edetate)

Question 43

The primary use of EDTA is in the treatment of

Answer 43

lead poisoning

Question 44

To prevent dangerous hypocalcemia, EDTA is given as the _______ ________ salt.

Answer 44

calcium disodium

Question 45

The most important adverse effect of EDTA is nephrotoxicity, including

Answer 45

renal tubular necrosis

Question 46

a polydentate bacterial product with an extremely high and selective affinity for iron and a much lower affinity for aluminum

Answer 46

Deferoxamine

Question 47

competes poorly for heme iron in hemoglobin and cytochromes

Answer 47

Deferoxamine

Question 48

a newer tridentate chelator with selectively high affinity for iron

Answer 48

Deferasirox

Question 49

used parenterally in the treatment of acute iron intoxication and in the treatment of iron overload caused by blood transfusion

Answer 49

Deferoxamine

Question 50

an oral drug approved for treatment of iron overload

Answer 50

Deferasirox

Question 51

Rapid intravenous administration of deferoxamine can cause _______ release

Answer 51

histamine

Question 52

a hydrated crystalline compound in which Fe2+ and Fe3+ atoms are coordinated with cyanide groups in a cubic lattice structure.

Answer 52

Prussian blue

Question 53

Prussian blue is approved for the treatment of contamination with radioactive ______ and intoxication with _______ salts.

Answer 53

cesium; thallium