Tetanus Immunoglobulin for Active Tetanus
Direct Answer
For active tetanus, administer 3,000-6,000 units of tetanus immunoglobulin (TIG) intramuscularly as soon as possible after diagnosis, which is 12-24 times higher than the 250-unit prophylactic dose used in wound management. 1
Treatment Protocol for Established Tetanus
Immediate Priorities
Secure the airway immediately and prepare for mechanical ventilation, as respiratory failure from laryngospasm and respiratory muscle rigidity is the leading cause of death in tetanus. 2 The case fatality rate remains 18-21% even with modern intensive care. 2
Immunologic Treatment with TIG
- Administer 3,000-6,000 units of TIG as soon as possible after diagnosis to neutralize circulating tetanus toxin. 1
- TIG cannot neutralize toxin already bound to nerve endings, which explains why even optimal treatment carries significant mortality risk. 1
- The standard of care remains intramuscular administration of TIG. 2
- When administering TIG, it must be given at a different anatomic site than any tetanus toxoid-containing vaccine using separate syringes. 1, 2
Important distinction: The therapeutic dose for active tetanus (3,000-6,000 units) is vastly different from the prophylactic dose for wound management (250 units). 1, 3 This is a critical point—do not confuse these two clinical scenarios.
Intrathecal TIG: Evidence vs. Current Practice
While the CDC recommends standard intramuscular administration 2, there is research evidence suggesting potential benefit from intrathecal administration:
- A meta-analysis of 942 patients across 12 trials showed intrathecal TIG reduced mortality with a relative risk of 0.71 (95% CI, 0.62-0.81) compared to intramuscular administration. 4
- In mild tetanus specifically, intrathecal TIG (250 IU) significantly reduced disease progression, hospital stay, ICU stay, need for tracheostomies, and sedative requirements. 5
- Another study showed that only 3 of 49 patients (6%) worsened with intrathecal TIG versus 15 of 48 (31%) with intramuscular administration. 6
However, current CDC guidelines do not recommend intrathecal administration as standard practice, and the intramuscular route remains the standard of care in the United States. 2 The intrathecal route may be considered in resource-limited settings or severe cases, but this is not part of routine U.S. guidelines.
Active Immunization During Acute Management
- Administer tetanus toxoid vaccine (Td preferred for adults ≥7 years) immediately during acute management at a separate anatomic site from TIG using a separate syringe. 2, 3
- This is critical because tetanus infection does not confer immunity—patients who survive tetanus remain fully susceptible to future infections unless actively immunized. 2
- For adults ≥7 years, Td is the preferred preparation. 2
- Use only adsorbed toxoid when TIG and tetanus toxoid are given together. 2
Wound Management
- Perform thorough surgical debridement of all necrotic tissue to remove anaerobic conditions favorable for Clostridium tetani growth. 2
- Proper wound cleaning and debridement are as critical as immunization in tetanus management. 2
Special Population Considerations
Elderly Patients
- Older adults have significantly higher mortality from tetanus. 2
- Prioritize TIG administration in patients >60 years if supplies are limited, as 49-66% of those ≥60 years lack protective levels of circulating antitoxin. 2, 7
Immunocompromised Patients
- Severely immunocompromised patients require TIG regardless of vaccination history. 2
- This includes patients with HIV infection or severe immunodeficiency. 2, 7
Patients with Unknown/Incomplete Vaccination Status
- Treat patients with unknown or uncertain vaccination histories as having had no previous tetanus toxoid doses. 7, 3
- These patients require both TIG and tetanus toxoid vaccine at separate sites. 7, 3
- They must complete a 3-dose primary tetanus vaccination series for long-term protection. 7
Critical Clinical Pearls
- Despite proper treatment with TIG, tetanus still carries an 18-21% mortality risk, emphasizing the importance of prevention through proper immunization. 1, 2
- The therapeutic dose for active tetanus (3,000-6,000 units) is 12-24 times higher than prophylactic dosing (250 units)—this is not a minor difference. 1, 3
- TIG works by neutralizing circulating toxin but cannot reverse toxin already bound to nerve endings, which is why early administration is crucial. 1
- Natural tetanus infection provides no immunity whatsoever—active immunization with tetanus toxoid must be initiated during acute management. 2
- In mass-casualty settings with limited TIG supply, prioritize patients >60 years and immigrants from regions outside North America/Europe. 2, 7
Common Pitfalls to Avoid
- Do not confuse the prophylactic dose (250 units) with the therapeutic dose (3,000-6,000 units) for active tetanus—this is the most critical error to avoid. 1, 3
- Do not assume that tetanus infection confers immunity—always administer tetanus toxoid vaccine during acute management. 2
- Do not administer TIG and tetanus toxoid at the same anatomic site—use separate syringes at different sites. 1, 2, 3
- Do not delay TIG administration—it should be given as soon as possible after diagnosis. 1
- Do not forget that respiratory management takes priority over all other interventions. 2