What is the treatment for colchicine poisoning?

Treatment of Colchicine Poisoning

The treatment of colchicine poisoning is essentially supportive as there are no effective means to remove colchicine from tissues and blood once toxicity occurs. 1 Management focuses on preventing further absorption, providing supportive care, and addressing complications across the three sequential phases of toxicity.

Clinical Presentation of Colchicine Poisoning

Colchicine poisoning typically progresses through three phases:

Phase 1 (0-24 hours after ingestion)

• Gastrointestinal symptoms: abdominal pain, nausea, vomiting, diarrhea
• Cholera-like syndrome with significant fluid loss
• Dehydration and shock
• Peripheral leukocytosis
• Acute renal failure
• Seizures may occur

Phase 2 (24-72 hours after ingestion)

• Multiorgan failure:
  • Bone marrow suppression
  • Renal insufficiency
  • Adult respiratory distress syndrome
  • Cardiac arrhythmias
  • Disseminated intravascular coagulation
  • Neurological disturbances
  • Coma and death

Phase 3 (if patient survives)

• Recovery of bone marrow
• Rebound leukocytosis
• Resolution of organ failure
• Alopecia 1, 2

Immediate Management

1. Gastrointestinal decontamination:

   • Gastric lavage if presentation is within 60 minutes of ingestion 3
   • Activated charcoal (multiple doses may be beneficial due to enterohepatic recirculation) 3, 4

2. Fluid resuscitation:

   • Aggressive IV fluid therapy to prevent shock
   • Electrolyte replacement as needed 2, 3

3. Cardiovascular support:

   • Vasopressors for hypotension
   • Cardiac monitoring for arrhythmias 1

Ongoing Management

1. Respiratory support:

   • Oxygen supplementation
   • Mechanical ventilation if respiratory failure develops
   • Consider extracorporeal life support in severe cases 4

2. Hematologic support:

   • Granulocyte colony-stimulating factor (G-CSF) for bone marrow suppression 5
   • Blood component therapy as needed 6

3. Renal support:

   • Renal replacement therapy for acute kidney injury
   • Note: Dialysis is ineffective for colchicine removal 2, 4

4. Monitoring:

   • Complete blood count
   • Renal and liver function tests
   • Coagulation studies
   • Serum electrolytes
   • Creatine kinase (for rhabdomyolysis) 1, 7

Special Considerations

1. Prognosis:

   • Ingestion of <0.5 mg/kg: generally survivable with milder toxicity
   • Ingestion of 0.5-0.8 mg/kg: severe reactions including myelosuppression
   • Ingestion of >0.8 mg/kg: 100% mortality reported 2, 3

2. Risk factors for increased toxicity:

   • Pre-existing liver or renal impairment
   • Concomitant use of CYP3A4 inhibitors (macrolides, ketoconazole, ritonavir)
   • P-glycoprotein inhibitors (verapamil, cyclosporine)
   • Statin use (increased risk of myopathy) 7, 3

3. Experimental treatments:

   • Fab fragment antibodies against colchicine have been used successfully in isolated cases but are not generally available 1, 3

Prevention of Colchicine Toxicity

• Maximum recommended oral doses: 3 mg daily in adults, 2 mg daily in children
• Dose reduction in patients with liver or renal impairment
• Avoid drug interactions with CYP3A4 inhibitors and P-glycoprotein inhibitors
• Regular monitoring in patients on chronic therapy 1, 7

Key Points to Remember

• Colchicine has a narrow therapeutic index with no clear distinction between toxic and lethal doses
• No effective means exist to remove colchicine once absorbed
• Treatment is primarily supportive
• Early recognition and aggressive supportive care are essential for survival
• Mortality is high with severe poisoning, particularly with delayed presentation 1, 3