Chelating Agents Flashcards

1
Q

What are chelating agents

A

Molecules with 2 or more electronegative groups used to prevent or reverse the toxic effects of heavy metals on enzyme

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2
Q

What determines the efficiency of the chelator agents

A

Efficiency depends on the number of ligands/functional groups available for metal binding

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3
Q

Properties of an ideal chelating agent

A

Water Solubility
Resistant to metabolic degradation
Ability to penetrate sites of metal storage
Readily excreted
Low affinity for Ca2+
Ability to retain its chelating properties at the pH of bodily fluids

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4
Q

Classification of chelating agents

A

Basis: Number of ligands
Monodentates
Bidentates
Polydentates

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5
Q

How can chelators cause toxicity

A

They may chelate essential metals as they are non specific

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6
Q

Example of monodentates

A

Sodiumthiocarbazone
Diphenylthiocarbazone

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7
Q

Example of Bidentates

A

Bimechaprol
Penicillinamine

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8
Q

Polydentates

A

Edetate calcium disodiumtrientene

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9
Q

MOA of dimercaprol

A

Interacts directly with metals in the blood, tissue and reactivates cellular Sulfurhydryl containing enzymes following metallic poisoning

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10
Q

Adverse effects of dimercaprol is reversed with

A

Atropine

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11
Q

Adverse effects of dimercaprol

A

Hypertension
Tachycardia
Headache
Vomiting

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12
Q

The major advantage of penicillamine is

A

The suitability for chronic oral administration

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13
Q

Dextro-penicillamine is supplied in ……… and the initial dose is ………

A

250mg

250mg 4times daily

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14
Q

What limits the use of EDTA as a chelating agent

A

Invivo chelating of essential calcium

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15
Q

The side effect of EDTA in high doses

A

Hepatotoxicity

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16
Q

The side effect of EDTA in mild doses

A

Fever
Chills
Myalgia
Nausea

17
Q

The daily dose of EDTA should not exceed

A

50mg/kg in adults
30mg/kg in children