Albendazole, marketed as Albenza among others, is medication used for the treatment of a variety of parasitic worm infestations. It is useful for giardiasis, trichuriasis, filariasis, neurocysticercosis, hydatid disease, pinworm disease, and ascariasis, among others. It is taken by mouth. Common side effects include nausea, abdominal pains, and headaches. Potentially serious side effects include bone marrow suppression which usually improves on stopping the medication. Liver inflammation has been reported and those with prior liver problems are at greater risk. It is pregnancy category C in the United States and category D in Australia, meaning it may cause harm if taken by a pregnant women. Albendazole is a broad-spectrum antihelminthic agent of the benzimidazole type. Albendazole developed in 1975. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. The wholesale cost in the developing world is between 0.01 and 0.06 USD per dose. In the United States, however, it is very expensive as of 2014 at about 50 USD per dose.