Human Tetanus Immunoglobulin

Approved Indications:

• Post-exposure prophylaxis of tetanus:
• In individuals with wounds that are tetanus-prone (e.g., deep puncture, contaminated, avascular injuries) who are either unvaccinated, incompletely vaccinated, or whose immunization history is uncertain.
• Treatment of clinical tetanus (Tetanus Therapeutic Use):
• As adjunctive therapy in patients diagnosed with active tetanus infection, in combination with appropriate antimicrobial therapy and supportive care.

Important Off-label / Clinically Accepted Uses:

• Neonatal tetanus management:
• Occasionally used in resource-limited or outbreak scenarios where passive immunity is required rapidly in neonates exposed to Clostridium tetani.

Route of Administration: Intramuscular (IM) injection only.
Formulation: Sterile solution for injection, available in single-dose vials.

Adults (Post-exposure prophylaxis):

• 250 IU as a single dose IM.
• If the wound is especially severe or more than 24 hours old, 500 IU may be administered.

Adults (Treatment of tetanus):

• 3,000 to 6,000 IU administered IM in a single dose, given as early as possible. Higher doses (up to 10,000 IU) may be used in severe cases, based on clinical judgment.

Pediatrics:

• Same dosage as adults (based on clinical need, not body weight), especially in post-exposure prophylaxis.
• In neonates or small children, volume may be adjusted and administered at multiple sites if needed.

Elderly:

• No specific dosage adjustment required. Monitor for local or systemic reactions.

Renal/Hepatic Impairment:

• No dose adjustment necessary.

Administration Notes:

• Do not administer intravenously.
• Preferably inject into the gluteal or anterolateral thigh muscle.
• If the volume exceeds 5 mL, split the dose across multiple sites.
• Avoid injection into fat tissue to ensure proper absorption.

Human Tetanus Immunoglobulin (TIG) provides passive immunity by supplying high titers of neutralizing antibodies (IgG) against the tetanus neurotoxin produced by Clostridium tetani. These antibodies bind to and inactivate free tetanospasmin before it binds to nerve endings. Since the toxin irreversibly binds to neurons, early administration of TIG prevents progression or worsening of symptoms, especially in post-exposure scenarios or early stages of clinical tetanus.

• Absorption: Slowly absorbed from the intramuscular site into systemic circulation.
• Bioavailability: High, with near-complete systemic availability over 2–3 days.
• Distribution: Distributed throughout the extracellular fluid; does not cross blood-brain barrier.
• Metabolism: Catabolized in the liver and reticuloendothelial system into peptides and amino acids.
• Half-life: Approximately 3 to 4 weeks in immunocompetent individuals.
• Elimination: Metabolic degradation; no active renal elimination.
• Onset of Action: Passive immunity begins within 24 hours post-injection and peaks around 48–72 hours.
• Duration of Action: Protective levels maintained for approximately 3 to 4 weeks.

• Pregnancy:
  Human Tetanus Immunoglobulin is considered safe in pregnancy. Though not classified under an FDA pregnancy category anymore, its use is recommended when clinically indicated, especially for tetanus-prone wounds in unvaccinated or partially vaccinated pregnant women.
• Lactation:
  TIG is safe during breastfeeding. It does not pass into breast milk in significant quantities and poses minimal risk to nursing infants.
• Caution:
  No teratogenic effects observed. Use when clearly needed. No adverse fetal outcomes reported in human data.

• Primary Class: Passive Immunizing Agent
• Subclass: Human Normal Immunoglobulin (Specific) – Antitoxin
• Category: Tetanus Antitoxin (Immunoglobulin)

• Known hypersensitivity to human immunoglobulin preparations
• History of anaphylactic reaction to immunoglobulins
• IgA-deficiency with documented antibodies against IgA and a history of hypersensitivity

• Hypersensitivity Reactions: Rare but possible; anaphylaxis may occur, especially in IgA-deficient patients.
• Thrombosis Risk: High doses or patients with predisposing risk factors (e.g., cardiovascular disease, immobility) may have a rare risk of thrombosis.
• Hemolysis: Rare cases of hemolytic anemia have been reported post-administration.
• Infection Transmission Risk: Although screened, there remains a theoretical risk of transmission of infectious agents (e.g., HIV, hepatitis), but no confirmed cases exist.
• Injection Site Reactions: Pain, redness, swelling, or induration may occur.
• Monitoring: Watch for signs of allergic reactions, especially during the first 30 minutes post-injection.

Common (≥1%):

• Local: Pain, swelling, redness at injection site
• Systemic: Mild fever, malaise, headache

Uncommon (<1%):

• Nausea
• Arthralgia
• Myalgia

Rare but Serious:

• Anaphylactic shock
• Hypersensitivity reactions (e.g., urticaria, chest tightness)
• Hemolytic anemia
• Thrombosis (very rare)

Onset: Local reactions usually occur within 24 hours; systemic reactions within 72 hours.

• Live Attenuated Vaccines (e.g., MMR, varicella):
  Administration of TIG may reduce efficacy of live vaccines. If such vaccines are needed, delay for at least 3 months after TIG administration.
• Other Immunoglobulins:
  Avoid co-administration with other immunoglobulins unless specifically indicated.
• No known food or alcohol interactions.
• No significant CYP450 enzyme involvement.

• WHO Recommendation (Latest):
  Emphasizes the importance of TIG in both therapeutic and prophylactic roles, especially in low-resource settings where vaccination records are unclear.
• CDC Guidelines (Updated):
  Prophylaxis with TIG is mandatory for tetanus-prone wounds in patients with incomplete or unknown vaccination status.
• EMA Update:
  Reinforced guidance on safe use in pregnancy and lactation; no change in dosage or administration protocol.

• Temperature: Store at +2°C to +8°C (Refrigerated); Do not freeze.
• Light Protection: Keep in original packaging, protect from light.
• Handling: Gently invert to mix before administration; do not shake vigorously.
• Shelf Life: Typically 36 months from manufacturing if properly stored.
• Reconstitution: Not applicable—supplied in ready-to-use form.