1. Clinical Overview
Tetanus Immunoglobulin (TIG) is a sterile, concentrated solution of immunoglobulin G (IgG) antibodies derived from the pooled plasma of human donors hyperimmunized with tetanus toxoid. It provides passive immunity against tetanus by neutralizing circulating tetanus toxin. It is a critical biological for post-exposure prophylaxis and adjunctive therapy in the management of tetanus infection, especially in the Indian context where tetanus remains a significant public health concern due to incomplete vaccination coverage and high-risk occupational exposures.
| Onset | Duration | Bioavailability |
|---|---|---|
| Rapid, with detectable antibody levels within hours of intramuscular administration. | Approximately 28 days (4 weeks). The half-life of IgG is about 21-28 days, providing passive protection for the incubation period of Clostridium tetani. | 100% via intramuscular route (intended route). Intravenous administration is not standard for TIG. |
2. Mechanism of Action
Tetanus Immunoglobulin provides immediate, short-term passive immunity against tetanus. It contains high titers of antibodies specific to tetanus toxin (tetanospasmin). These antibodies bind directly to circulating, unbound tetanus toxin, forming antigen-antibody complexes. This neutralization prevents the toxin from binding to neuronal gangliosides and being transported retrogradely to the central nervous system, thereby inhibiting its action on inhibitory interneurons (Renshaw cells) in the spinal cord and brainstem.
3. Indications & Uses
- Prophylaxis of tetanus in wound management for individuals with tetanus-prone wounds and unknown/ incomplete (<3 doses) tetanus vaccination history.
- Treatment of clinical tetanus as an adjunct to wound care, antibiotics, muscle relaxants, and supportive measures.
4. Dosage & Administration
Adult Dosage: Prophylaxis: 250-500 IU intramuscularly. Treatment of Tetanus: 3000-6000 IU intramuscularly, with part of the dose infiltrated around the wound if possible. Indian National Immunization Schedule (NIS) and standard guidelines recommend 250 IU for prophylaxis.
Administration: Administer by DEEP INTRAMUSCULAR injection, preferably in the upper outer quadrant of the gluteal region or the deltoid muscle. Do NOT administer intravenously. For tetanus treatment, a portion of the dose may be infiltrated around the wound site. Use a separate syringe, needle, and injection site from tetanus toxoid vaccine. Shake vial gently before use. Do not mix with other products.
5. Side Effects
Common side effects may include:
- Pain, tenderness, erythema, and induration at the injection site.
- Mild fever, chills, headache, malaise.
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Live Attenuated Vaccines (e.g., MMR, Varicella, Yellow Fever) | TIG may interfere with the immune response to live viral vaccines. Administration should be deferred for at least 3 months after TIG administration, or TIG should be given at least 2 weeks after the vaccine. | Moderate |
| Other Immunoglobulin Preparations | May increase the risk of systemic adverse reactions. | Moderate |
7. Patient Counselling
- DO inform your doctor about any history of allergies, especially to blood products or immunoglobulins.
- DO report any previous vaccinations, especially recent live vaccines.
- DO expect some pain, redness, or swelling at the injection site; this is common.
- DON'T rub the injection site.
- DON'T miss the concurrent tetanus toxoid vaccine if advised; it is crucial for long-term protection.
8. Toxicology & Storage
Overdose: Unlikely due to fixed vial sizes. Theoretical overdose could lead to increased severity of known side effects, particularly systemic inflammatory reactions (fever, chills, headache, myalgia).
Storage: Store at +2°C to +8°C (in a refrigerator). DO NOT FREEZE. Protect from light. Keep the vial in the outer carton. Do not use if the solution is cloudy or contains particulate matter. Do not use after the expiry date.