## **Core Concept**
The administration of rabies immunoglobulin (RIG) is a critical component of post-exposure prophylaxis (PEP) for individuals bitten or exposed to potentially rabid animals. RIG provides immediate antibodies against the rabies virus. The dose and administration route are crucial for effective prophylaxis.

## **Why the Correct Answer is Right**
The correct dose of rabies immunoglobulin for post-exposure prophylaxis is **20 IU/kg**. This dose is administered immediately after exposure and is essential for providing immediate protection against the rabies virus. The RIG is typically infiltrated into the wound(s) if possible, with any remaining volume injected intramuscularly at a site distant from the vaccine injection site. This approach helps to neutralize the virus at the site of entry and systemically.

## **Why Each Wrong Option is Incorrect**
- **Option A:** 10 IU/kg - This is half the recommended dose and would likely provide insufficient immediate protection against the rabies virus.
- **Option B:** 15 IU/kg - Still lower than the recommended dose, potentially compromising the efficacy of the post-exposure prophylaxis.
- **Option D:** 30 IU/kg - While seemingly closer to or even higher than the recommended dose, administering more than the recommended dose does not enhance efficacy and could increase the risk of adverse reactions.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that the dose of rabies immunoglobulin is **20 IU/kg**, and it must be administered only once immediately after exposure. Additionally, it's essential to infiltrate the RIG into the wound if possible, to directly target the virus at the site of entry.

## **Correct Answer:** . 20 IU/kg