Used primarily to treat parasitic infections such as African sleeping sickness (caused by Trypanosoma brucei gambiense) and leishmaniasis. Also effective against certain fungal infections, particularly Pneumocystis jirovecii pneumonia (PCP), which commonly affects immunocompromised patients like those with HIV/AIDS. Administered via intravenous or intramuscular injection for systemic infections. Inhaled form is used as a preventive measure for PCP in high-risk individuals. Has shown activity against some protozoa and is occasionally used off-label for other opportunistic infections.