Dose of Rabies immunoglobulin is
**Core Concept**
Rabies immunoglobulin (RIG) is a critical component of post-exposure prophylaxis (PEP) for rabies, providing immediate, passive immunity against the virus. The dose of RIG is crucial to ensure effective neutralization of the virus and prevention of rabies.
**Why the Correct Answer is Right**
The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) recommend a dose of 20 IU/kg of RIG for post-exposure prophylaxis. This dose is sufficient to neutralize the virus and prevent its replication. The RIG is administered at the site of the bite or scratch, and the remaining dose is given intramuscularly. The mechanism of action involves the binding of RIG to the rabies virus, preventing it from entering the host cells and replicating.
**Why Each Wrong Option is Incorrect**
**Option A:** 10 IU/kg - This dose is insufficient to provide adequate protection against the virus, increasing the risk of rabies.
**Option B:** 30 IU/kg - This dose is higher than the recommended amount and may increase the risk of adverse reactions without providing additional benefit.
**Option C:** 40 IU/kg - This dose is excessive and not supported by any clinical evidence, potentially leading to complications.
**Clinical Pearl / High-Yield Fact**
It's essential to administer RIG within 7 days of the bite or scratch to ensure effective neutralization of the virus and prevent rabies. Delayed administration may reduce the efficacy of RIG.
**Correct Answer:** D. 20 IU/kg