Drug used orally for treating scabies: March 2009
**Core Concept**
Oral treatment for scabies involves using medications that are systemically absorbed to kill the mite and its eggs. This approach is particularly useful in severe or resistant cases, as well as in treating scabies in immunocompromised individuals.
**Why the Correct Answer is Right**
The correct answer is ivermectin, an anthelmintic drug that has been shown to be effective in treating scabies. Ivermectin works by binding to the glutamate-gated chloride channels in the nerve and muscle cells of the scabies mite, leading to paralysis and death of the mite. This mechanism is similar to its action against other parasites, such as roundworms and hookworms.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not mention any specific drug used for treating scabies.
* **Option B:** This option is incorrect because permethrin is typically used topically, not orally, for treating scabies.
* **Option C:** This option is incorrect because it does not mention any specific drug used for treating scabies.
**Clinical Pearl / High-Yield Fact**
Ivermectin is a broad-spectrum antiparasitic agent that can be used to treat a range of parasitic infections, including scabies, strongyloidiasis, and onchocerciasis. When used to treat scabies, ivermectin is typically given in a single oral dose of 200 micrograms per kilogram of body weight.
**Correct Answer: D. Ivermectin**