Antidotes

Question 1

Antidotes

Answer 1

• specific actions against activity/effect of poisons
• can become toxic
• adverse effects possible; less likely if diagnosis correct
• decontamination not carried out 1st
• some animals may be less tolerant than others due to age or species

Question 2

Group name for metal poisoning antidotes

Answer 2

Chelators

Question 3

Common metal chelators (5)

Answer 3

• Calcium Disodium (CaNa2-EDTA)
• Succimer (DMSA)
• Dexferoxamine
• D- penincillamine
• British antilewisite (BAL)

Question 4

Calcium Disodium

Answer 4

• DOC for lead poisoning
• used for lead and zinc toxicosis
• adverse effects: chelate other divalent cations & hypocalcemia in large animals

Question 5

Succimer (DMSA)

Answer 5

• used for Pb toxicosis in humans and dogs

Question 6

Dexferoxamine

Answer 6

• used for Iron toxicosis only
• starting to use in aluminum assc. Alzheimer’s

Question 7

D-penincillamine

Answer 7

• used for copper, zinc, and lead toxicosis
• Zn use more common
• can cause allergic rxns

Question 8

British antilewisite (BAL)

Answer 8

• mainly for arsenic toxicosis
• can be used for lead and mercury poisoning

Question 9

Cardiac glycoside poisoning

Answer 9

• digitoxin-immune Fab frag.: heart failure
• caused by bufo-toads and fox glove plants

Question 10

Acetaminophen poisoning

Answer 10

• N- acetylcysteine used to treat
• Tx effective 8 to 16 hrs post-exposure
• overdosage: unlikely, anaphylactic rxns possible, nausea or/and vomiting

Question 11

Methemoglobinemia

Answer 11

• Tx: Vitamin C (Ascorbic acid); reverses methemoglobinemia in felines
• rapidly absorbed
• distributed in milk and body
• adverse effects: acidifies urine (can affect other drugs), can interfere with oral Fe absorption

Question 12

Copper poisoning

Answer 12

• important in sheep
• Tx: ammonium molybdate & ammonium tetrathiomolybdate (promoted Cu excretion)
• NOT CURRENTLY FDA APPROVED
• K9 Tx w/ D-penincyclimine

Question 13

Antivenoms

Answer 13

• most don’t have antivenoms
• usually carry for crotalids and elipadae, widow spiders, scorpions, jellyfish
• polyvalent and monovalent
• must store < 37 C and use within 48hrs

Question 14

What is ethanol used for?

Answer 14

• antifreeze poisoning
• prevents metabolic acidic intermediate formation
• adverse effects: CNS depression, Diuretic so excessive fluid loss
• rapidly metabolized, so repeated admin.
• most effective within 4 hrs exposure

Question 15

4-MP: Fomepizole usage

Answer 15

• better for antifreeze poisoning
• not FDA approved
• no commercial form
• less CNS depression

Question 16

Nitrate/nitrite poisoning

Answer 16

• Methylene blue
• can also be used for chlorate poisoning
• corrects methemoglobinemia
• not FDA approved

Question 17

Anticoagulant Rodenticides

Answer 17

• Tx: Phytonadione (Vitamin K1)
• adverse effects: IV use can casue anaphlyactic rxns, bleeding @ injection site
• warfarin is example

Question 18

Cholecalciferol rodenticide

Answer 18

• Tx: calcitonin

Question 19

Atropine sulfate (antidote)

Answer 19

• used for organophosphate poisoning
• short 1/2 life, repeat doses if needed
• Adverse rxns: CNS depression and disorientation, dry mucous membranes, hypomotility GIT

Question 20

Pralidoxime Chloride (Antidote)

Answer 20

• used as reversal for organophosphate toxicosis
• most effective if given within 24 hrs
• effective after 24 hrs in delayed dermal absorption

Question 21

Cyanide poisoning

Answer 21

• Tx: sodium nitrate and sodium thiosulfate
• large thiosulfate doses w/o nitrate also helpful