What is the first-line treatment for ascariasis in adults?

Albendazole is recognized as the first-line treatment for ascariasis in adults due to its efficacy against Ascaris lumbricoides, the parasite responsible for the infection. Albendazole works by inhibiting the parasite's metabolism, specifically by disrupting the synthesis of microtubules, which ultimately leads to its death.

In clinical practice, albendazole is favored because it has a favorable safety profile, a convenient dosing regimen, and a broad spectrum of activity against a variety of helminths, making it a more versatile option compared to other treatments. Pyrantel and mebendazole are also effective against ascariasis, but they are typically considered secondary options. Pyrantel is less potent against adult Ascaris infections and is limited in its use due to drug resistance. Mebendazole, while effective, is often supplanted by albendazole for this specific indication due to convenience and effectiveness. Levamisole is primarily used as an immunomodulator and has limited efficacy against helminths compared to the other agents listed.

Thus, the choice of albendazole is supported by both clinical guidelines and extensive research demonstrating its effectiveness for treating ascariasis in adults.