Tetanus Immunoglobulin Dosage for Active Tetanus Disease
For a patient with established tetanus disease, administer 3,000-6,000 units of tetanus immunoglobulin (TIG) intramuscularly as soon as possible after diagnosis. 1, 2
Standard Therapeutic Dosing
The therapeutic dose for active tetanus is 3,000-6,000 units IM, which is 12-24 times higher than the 250-unit prophylactic dose used in wound management. 1, 2
The FDA-approved product information for HyperTET documents successful treatment of 20 tetanus patients using single doses of 3,000-6,000 antitoxin units, with a 30% mortality rate that compared favorably to historical controls using equine antitoxin. 2
TIG must be administered at a different anatomic site than any tetanus toxoid-containing vaccine, using separate syringes. 1
Critical Mechanism and Timing
TIG works by neutralizing circulating tetanus toxin but cannot neutralize toxin already bound to nerve endings, which explains why early administration is crucial. 1
The CDC emphasizes that TIG should be administered as soon as possible after diagnosis to maximize effectiveness. 1
Peak blood levels of IgG are obtained approximately 2 days after intramuscular injection, with a half-life of approximately 23 days in circulation. 2
Concurrent Active Immunization Required
Always administer tetanus toxoid vaccine (Td preferred for adults ≥7 years) simultaneously with TIG at a separate anatomic site, as natural tetanus infection provides no immunity whatsoever. 3
Patients who survive tetanus remain fully susceptible to future infections unless actively immunized with tetanus toxoid. 3
Use only adsorbed toxoid when TIG and tetanus toxoid are given together. 3
Evidence Regarding Optimal Dosing
A CDC data analysis of 545 tetanus cases from 1965-1971 found that survival was no better with 8,000 units of TIG than with 500 units, though an optimal dose could not be definitively determined. 2
Despite this uncertainty, the standard of care remains 3,000-6,000 units IM based on historical clinical experience and FDA-approved dosing. 1, 2
Intrathecal Administration Controversy
Some research suggests potential benefit from intrathecal TIG administration (250 IU intrathecally showed lower mortality than 1,000 IU IM in one study), but this remains investigational. 4
The standard of care remains intramuscular administration of 3,000-6,000 units, as intrathecal use is not FDA-approved and guideline recommendations consistently specify IM dosing. 1, 3, 2
Critical Clinical Context
Despite proper treatment with TIG, tetanus still carries significant mortality risk (18-21% case fatality rate even with modern intensive care), emphasizing the importance of prevention through proper immunization. 1, 3
Respiratory failure from laryngospasm and respiratory muscle rigidity is the leading cause of death in tetanus, requiring immediate airway management and preparation for mechanical ventilation. 3
Older adults (>60 years) have significantly higher mortality from tetanus and should be prioritized for TIG administration if supplies are limited. 3