**Core Concept**
Praziquantel is a medication used to treat schistosomiasis, a parasitic disease caused by infection with Schistosoma species. It works by causing changes in the permeability of the parasite's cell membrane, leading to the influx of calcium ions and subsequent muscle contraction, ultimately resulting in the expulsion of the parasite from the host.

**Why the Correct Answer is Right**
Praziquantel is a calcium channel agonist that binds to calmodulin, a calcium-binding protein, which in turn activates the parasite's muscle contraction. This results in the paralysis and expulsion of the parasite from the host. The mechanism of action of praziquantel is not fully understood, but it is thought to involve the disruption of the parasite's calcium homeostasis.

**Why Each Wrong Option is Incorrect**
**Option A:**
* Incorrect because praziquantel is indeed effective against schistosomiasis, and its mechanism of action involves the disruption of the parasite's calcium homeostasis.

**Option B:**
* Incorrect because praziquantel is not a beta-lactam antibiotic, which is a different class of medication used to treat bacterial infections.

**Option C:**
* Incorrect because praziquantel is not a macrolide antibiotic, which is a different class of medication used to treat bacterial infections.

**Option D:**
* Incorrect because praziquantel is not a corticosteroid, which is a different class of medication used to treat inflammation and allergic reactions.

**Clinical Pearl / High-Yield Fact**
Praziquantel is the medication of choice for the treatment of schistosomiasis, but it is not effective against the larval stages of the parasite. Treatment with praziquantel should be repeated after several weeks to ensure that all stages of the parasite are eliminated.

**Correct Answer:** D.