Used primarily as an antimalarial agent, it acts as a prodrug that is metabolized to cycloguanil, an active metabolite that inhibits the Plasmodium falciparum dihydrofolate reductase enzyme, disrupting folate synthesis essential for parasite DNA replication. Commonly combined with atovaquone to enhance efficacy and reduce the risk of resistance development. Employed for malaria prophylaxis in travelers visiting endemic regions and in the treatment of acute uncomplicated malaria when paired with other antimalarials. Its use is favored in areas with chloroquine-resistant strains. Also investigated for potential synergistic effects in combination therapies targeting parasite mitochondrial electron transport.