This drug can clear trypanosomes from blood and lymph nodes and is active in late CNS stages of African sleeping sickness. It is :
**Core Concept**
The question is testing the knowledge of a specific antiparasitic drug used to treat African sleeping sickness. Trypanosomiasis is a disease caused by the parasite *Trypanosoma brucei* and is transmitted by the tsetse fly. The disease has two stages: the early hemolymphatic stage and the late CNS stage.
**Why the Correct Answer is Right**
The correct answer is Melarsoprol, a drug that belongs to the arsenical class of compounds. It works by inhibiting the synthesis of proteins and nucleic acids in the parasite, ultimately leading to its death. Melarsoprol is highly effective in clearing trypanosomes from the blood and lymph nodes, and it is also active against the late CNS stages of the disease. This is because it can cross the blood-brain barrier, allowing it to reach the parasites in the central nervous system.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Suramin is another antiparasitic drug used to treat African sleeping sickness, but it is not effective against the late CNS stages of the disease.
**Option B:** This option is incorrect because Eflornithine is an antiparasitic drug used to treat African sleeping sickness, but it is not active against the late CNS stages of the disease.
**Option C:** This option is incorrect because Pentamidine is an antiparasitic drug used to treat other types of trypanosomiasis, but it is not effective against African sleeping sickness.
**Clinical Pearl / High-Yield Fact**
Melarsoprol is a high-risk medication due to its potential to cause arsenic toxicity. The risk of toxicity is highest in patients with pre-existing kidney disease, and close monitoring of kidney function is essential when using this medication.
**Correct Answer: C. Melarsoprol**