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Antiprotozoal agents (ATC code: ATC P01) is a class of pharmaceuticals used in treatment of protozoan infection.
Protozoans have little in common with each other (for example, Entamoeba histolytica is less closely related to Naegleria fowleri than it is to Homo sapiens) and so agents effective against one pathogen may not be effective against another. However, metronidazole is selective for anaerobic organisms, and so it is effective against many (though not all) of these pathogens.
They can be grouped by mechanism or by organism.