How much immunoglobulin is administered after a tick bite? - briefly
The recommended dose of human rabies immunoglobulin after a tick bite is 20 IU per kilogram of body weight, infiltrated as much as possible around the wound and the remainder administered intramuscularly. This dosage is based on standard WHO guidelines for post‑exposure prophylaxis.
How much immunoglobulin is administered after a tick bite? - in detail
The recommended amount of rabies‑specific immunoglobulin given after a tick bite that poses a rabies risk is calculated on body weight. For human rabies immune globulin (HRIG), the dose is 20 IU per kilogram of the patient’s weight. The entire calculated volume should be infiltrated directly into and around the bite site; any remaining volume is administered intramuscularly at a site distant from the vaccine injection. When equine rabies immune globulin (ERIG) is used, the dosage is 40 IU per kilogram, following the same infiltration and supplemental intramuscular administration protocol. The immunoglobulin is administered only once, concurrently with the first dose of the rabies vaccine, and must be given as soon as possible after exposure, ideally within 24 hours.
Key points for proper administration:
- Calculate dose based on exact body weight; pediatric patients receive proportionally smaller volumes.
- Use sterile technique; dilute the product only if manufacturer instructions require it.
- Infiltrate the full dose into the wound(s); if multiple bites exist, distribute the volume among them.
- Administer any surplus intramuscularly in the deltoid or thigh, opposite the vaccine site.
- Record the total IU administered and the anatomical sites of infiltration for future reference.
- Monitor the patient for rare hypersensitivity reactions, especially when using ERIG.
The immunoglobulin provides passive immunity that bridges the period until active immunity develops from the vaccine series. No repeat dosing of the globulin is required; subsequent vaccine doses follow the standard post‑exposure schedule (days 0, 3, 7, 14, 28).