Antiprotozoal

Antiprotozoal agents (ATC code: ATC P01) is a class of pharmaceuticals used in treatment of protozoan infection.

A paraphyletic group, protozoans have little in common with each other. For example, Entamoeba histolytica, a unikont eukaryotic organism, is more closely related to Homo sapiens (humans), which also belongs to the unikont phylogenetic group, than it is to Naegleria fowleri, a "protozoan" bikont. As a result, agents effective against one pathogen may not be effective against another.

Antiprotozoal agents can be grouped by mechanism or by organism. Recent papers have also proposed the use of viruses to treat infections caused by protozoa.

Overuse or misuse of antiprotozoals can lead to the development of antiprotozoal resistance.