What is the treatment for a cobra bite?

Treatment of Cobra Bite

Immediately activate emergency services and transport the victim to a medical facility for antivenom administration, which is the only definitive treatment for cobra envenomation. 1

Immediate First Aid Measures

Critical actions to take immediately:

• Call emergency services for any person bitten by a venomous or possibly venomous snake 1
• Rest and immobilize the bitten extremity to minimize exertion and reduce systemic venom absorption through the lymphatic system 1, 2
• Remove rings, watches, and all constricting jewelry from the affected limb before swelling occurs, as this prevents ischemic injury 1, 2
• Transport rapidly to a hospital where antivenom is available—this is the only effective treatment and cannot be administered in the field 1, 2

The 2024 American Heart Association guidelines emphasize that walking or exertion increases flow of venom from the bite site, potentially worsening systemic toxicity. 1 Balance minimizing movement with avoiding delays in reaching definitive care.

Harmful Practices to AVOID

Do NOT perform the following interventions, as they are ineffective or harmful:

• NO ice application—unproven benefit and may cause tissue injury 1, 2
• NO suction devices (with or without incision)—ineffective for venom removal and may damage tissue 1, 2
• NO tourniquets—can worsen local tissue injury 1, 2
• NO electric shock therapy—ineffective and potentially harmful 1, 2
• NO pressure immobilization bandaging for cobra bites in most circumstances—while the 2010 guidelines suggested this for certain snake types, the 2024 guidelines note it is potentially harmful for North American snakes 1

Important caveat: Pressure immobilization bandaging was previously recommended for neurotoxic snake bites (like cobras) in some regions, but current evidence shows mixed results with potential for worsening tissue injury. 1 The 2024 American Heart Association guidelines specifically state this technique is potentially harmful for snakebites in the United States and Canada. 1

Hospital Management

Antivenom is the cornerstone of definitive treatment:

• Administer species-specific antivenom as soon as neurotoxic signs appear (ptosis, difficulty swallowing, respiratory weakness) 3, 4, 5
• Initial dose: 10 vials (or 100 ml) intravenously after hypersensitivity testing 3, 5
• Repeat dosing may be necessary—cobra envenomation can require very high doses of antivenom, particularly if neurotoxicity progresses 5, 6, 7
• Have epinephrine immediately available for potential anaphylactic reactions to antivenom 3, 8

Research on Thai cobra bites demonstrates that a 100 ml bolus of antivenom given at the onset of neurotoxic signs significantly reduces time on mechanical ventilation (10 hours vs 40 hours without adequate antivenom). 5 However, once paralysis is established, antivenom has limited effect on reversing the neuromuscular blockade. 4

Respiratory support:

• Prepare for intubation and mechanical ventilation—cobra venom causes areflexic flaccid paralysis that may require ventilatory support for 4-7 days or longer 4, 5, 8
• Monitor closely for respiratory failure even after antivenom administration, as neurotoxicity can progress despite treatment 5
• The neuromuscular block from cobra venom is non-depolarizing and poorly responsive to neostigmine 4

Critical Timing Considerations

Antivenom is most effective when given early:

• Maximum benefit occurs before paralysis develops 4
• Once paralysis is established, antivenom has minimal effect on reversing neuromuscular blockade, though it may prevent further deterioration 4
• Time to respiratory failure can be as short as 2-2.5 hours after the bite 4

Common Pitfalls to Avoid

• Delaying transport to attempt ineffective first aid measures like suction or ice application 2
• Underestimating antivenom requirements—cobra bites may require much higher doses than other snake envenomations 6, 7
• Failing to prepare for anaphylaxis when administering antivenom, which can cause severe bronchospasm and hypotension requiring adrenaline infusion 8
• Inadequate respiratory monitoring—neurotoxicity can progress rapidly and unpredictably 5