What is the management for a telmisartan (angiotensin II receptor antagonist) overdose?

Management of Telmisartan Overdose

The primary management for telmisartan overdose is supportive treatment with focus on maintaining blood pressure, as the most likely manifestation is hypotension, along with possible dizziness and tachycardia. 1

Clinical Presentation

• Most common manifestations:
  • Hypotension (primary concern)
  • Dizziness
  • Tachycardia
  • Bradycardia may occur due to parasympathetic (vagal) stimulation 1

Initial Management

1. Hemodynamic Stabilization

   • IV fluid resuscitation as first-line treatment for hypotension
   • Continuous cardiac monitoring
   • Frequent blood pressure measurements

2. Airway Management

   • Ensure patent airway, especially if patient has decreased level of consciousness

3. Decontamination

   • Consider gastric decontamination only for recent ingestions with protected airway
   • Note: Limited value if presentation is delayed beyond 1-2 hours post-ingestion

Pharmacological Management

For Persistent Hypotension:

1. Vasopressors

   • Initiate vasopressors (epinephrine, norepinephrine, dopamine) if hypotension persists despite fluid resuscitation
   • Titrate to effect based on blood pressure response

2. Calcium Administration

   • Consider IV calcium chloride or calcium gluconate
   • May repeat every 10-20 minutes for 3-4 doses if beneficial

3. Atropine

   • For symptomatic bradycardia: 0.5-1 mg IV
   • Note: Often has limited efficacy in angiotensin II receptor blocker overdose

4. High-Dose Insulin Therapy with Glucose Supplementation

   • For refractory hypotension or shock
   • Initial bolus of 1 U/kg IV
   • Continuous infusion of 1 U/kg/hour
   • Co-administer with dextrose
   • Monitor blood glucose levels closely

5. Glucagon

   • Consider 5-10 mg IV bolus over 3-5 minutes
   • Follow with continuous infusion of 1-5 mg/hour
   • Caution: Monitor for vomiting and protect airway

Important Considerations

• Hemodialysis is not effective for removing telmisartan due to its high protein binding 1
• Monitor for rebound hypertension during recovery
• Patients with liver disease may be at higher risk for toxicity and require more aggressive management
• Continuous monitoring of:
  • Cardiac status
  • Blood pressure
  • Blood glucose
  • Electrolytes (particularly potassium)
  • Fluid status

Severe Cases

• For life-threatening poisoning with cardiogenic shock unresponsive to pharmacological interventions, consider Extracorporeal Life Support (VA-ECMO)
• Early consultation with ECMO team is recommended in cases of severe, refractory shock

Discontinuation of Treatment

• Begin tapering vasopressors and other interventions as the patient stabilizes
• Continue monitoring for rebound hypotension or bradycardia
• Ensure patient is hemodynamically stable for at least 24 hours before considering discharge

Follow-up

• Cardiac assessment before discharge
• Consider evaluation for intentional overdose if applicable
• Patient education regarding medication safety

Remember that telmisartan has a long elimination half-life (approximately 24 hours) 2, 3, which may contribute to prolonged symptoms requiring extended monitoring and supportive care.