Test 4: 54 rodenticides

Question 1

secondary toxicosis occurs with what type of anticoagulant rodenticide?

Answer 1

2nd gen- increased potency

Brodifacoum, difenacoum, diphacinone and bromadiolone

Question 2

ADME of anticoagulant rodenticides

Answer 2

Absorption – gastrointestinal tract

Distribution – carried bound to albumin, concentrated in liver

Metabolism – occurs in liver via MFO → Some inactive metabolites excreted via kidneys

Elimination – 1/2 lives

• Warfarin: dogs – 14.5 hrs, humans – 48 hrs
• Diphacinone: humans – 15-20 days
• Brodifacoum: assumed to be ≥ diphacinone

Question 3

predisposing factors to anticoag rodenticide toxicity

Answer 3

• High dietary fat intake
• Prolonged oral antibiotic therapy
• Biliary obstruction and liver disease
• Hypoalbuminemia
• Concurrent drug administration that is protein bound
• Uremia
• Aspirin therapy

Question 4

MOA of anticoag rodenticides

Answer 4

stop recycling of VitK

Question 5

clotting factors that require vit K

Answer 5

2,7,9,10

Question 6

clinical signs of vit K rodenticides

Answer 6

Usually takes 3-5 days for signs to appear

• Acute death – less common → Hemorrhage into CNS, abdominal cavity, pericardial sac, mediastinum, or thorax
• Depression, anorexia, anemia
• Pale mm, dyspnea, hematemesis, epistaxis
• Scleral, intraocular, conjunctival, nasal, oral, urogenital, SQ hemorrhages

Question 7

blood work of anticoag rodenticides

Answer 7

↑PT time within 24-48 hrs
↑PTT time after 48 hrs
↓ to normal platelet count: ↓ if hemorrhage
PCV and TS ↓ if blood loss

Question 8

xray of dog with anticoag rodenticide can show

Answer 8

• Increased mediastinal soft tissue opacity
• Extra- and intra-lumenal tracheal narrowing
• Pleural effusion
• Patchy interstitial or alveolar pattern

Question 9

post mortem findings of anticoag rodenticide

Answer 9

Generalized hemorrhage
§ Thoracic or abdominal cavities
§ Mediastinum, pericardium
§ Periarticular space and tissues
§ Subcutaneous tissues
§ Subdural space
* +/- Hemorrhage into GI tract
* Flaccid and hemorrhagic heart
* Centrilobular hepatic necrosis secondary to anemia and hypoxemia

Question 10

treatment of acute ingestion of anticoag rodenticides

Answer 10

small dose:
* Close observation
OR
* test PT at 48-72hr post ingestion

unknown dose:
* If < 1hr since ingestion or unknown when ingested, induce emesis, then activated charcoal and cathartic
* If > several hrs after ingestion, activated charcoal and cathartic

Follow this with either:
* Vit K PO q12hrs for 4 weeks
OR
* Check PT at 48-72hr post ingestion, starting Vit K as above if prolonged

Recheck PT 48-72hr after last dose of Vit K, treat for 2 more weeks if prolonged (Repeat this step as needed)

Question 11

treatment for symptomatic anticoag rodenticide ingestion

Answer 11

• FFP or FWB for active clotting factors
• FWB or pRBCs + FFP if anemic (and clinical)
• Vit K SQ once
• Continue Vit K SQ or PO q 12hrs for 4 weeks
• Monitor OSPT at 48-72hr after last dose of Vit K, treat for 2 more weeks if prolonged (Repeat this step as needed)

2,7,9,10 clotting factors