How many doses of immunoglobulin are given after a tick bite? - briefly
A single dose of rabies immune globulin (20 IU per kilogram of body weight) is administered after a tick bite, infiltrated around the wound and the remainder given intramuscularly. This is the only immunoglobulin dose required in the post‑exposure regimen.
How many doses of immunoglobulin are given after a tick bite? - in detail
A single dose of rabies immunoglobulin is administered after a tick bite that poses a risk of rabies exposure. The dose is calculated at 20 IU (international units) per kilogram of body weight. For an adult weighing 70 kg, the total volume equals 1,400 IU, typically supplied in a 5 mL vial of 300 IU/mL; the required amount is drawn and the remainder discarded.
The immunoglobulin is infiltrated directly around the bite site as far as anatomically feasible, ensuring that the entire calculated dose is delivered into the wound tissue. Any remaining volume is injected intramuscularly at a site distant from the vaccine administration, usually the deltoid muscle.
Following the immunoglobulin, a rabies vaccine series begins on the same day (day 0) and continues on days 3, 7, and 14. For immunocompromised individuals, an additional dose on day 28 is recommended.
Key points for proper administration:
- Verify that the tick bite occurred in a region where rabies is endemic or that the animal is suspected of being rabid.
- Use human rabies immunoglobulin (HRIG) or, where unavailable, equine rabies immunoglobulin (ERIG) with appropriate monitoring for hypersensitivity.
- Do not repeat the immunoglobulin dose; a single calculated dose provides passive immunity until active immunity develops from the vaccine series.
- Document the exact dose, route of infiltration, and site of any remaining injection.
In summary, one calculated dose of rabies immunoglobulin, administered locally at the bite site, is required, followed by a four‑dose vaccine schedule to complete post‑exposure prophylaxis.