Dose of Human Rabies Immunoglobulin is:
**Core Concept**
Human Rabies Immunoglobulin (HRIG) is a post-exposure prophylaxis (PEP) measure used to neutralize the virus and prevent the development of clinical rabies. HRIG is a concentrated preparation of antibodies against the rabies virus.
**Why the Correct Answer is Right**
The recommended dose of HRIG is 20 IU/kg body weight, administered intramuscularly as soon as possible after exposure. This dose is based on the amount of antibodies required to neutralize the virus in the bitten individual. HRIG is usually administered at the site of the bite, if possible, and the remaining dose is given intramuscularly in the deltoid region or the anterior aspect of the thigh. The dose of HRIG should not be reduced or omitted, as it is essential for preventing the development of clinical rabies.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the dose of HRIG is not 10 IU/kg body weight. This dose is lower than the recommended dose and may not provide adequate protection against the rabies virus.
* **Option B:** This option is incorrect because the dose of HRIG is not 30 IU/kg body weight. This dose is higher than the recommended dose and may increase the risk of adverse reactions.
* **Option C:** This option is incorrect because the dose of HRIG is not 40 IU/kg body weight. This dose is significantly higher than the recommended dose and is not supported by clinical evidence.
**Clinical Pearl / High-Yield Fact**
HRIG is usually administered in conjunction with the first dose of rabies vaccine to provide immediate immunity and prevent the development of clinical rabies. It is essential to administer HRIG as soon as possible after exposure to maximize its effectiveness.
**Correct Answer: C. 20 IU/kg body weight.**