A compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, for use in the treatment of a patient infected with pathogenic organisms; wherein X and Y are each independently selected from C, N, O and S, provided at least one of X and Y is N, O or S; wherein R1 and R2 are each independently selected from an optionally substituted C1-C8
alkyl, C1-C8 alkenyl,
aryl, heteroaryl or alkylaryl group; and wherein Z is selected from H, —CN, —NO2, —NR3R4, —NR5(CO)R6; C1-C4
alkyl, C1-C4 alkoxy, —(CO)WR12, hydroxy, amino,
thiol, chloro, fluoro, CF3, CHF2 or CH2F groups. The compounds may be effective in treating patients / animals infected with parasites selected from
Schistosoma, Haemonchus,
Eimeria, Echinococcus, Dirofilaria, Fasciola or Plasmodium parasites. Additionally or alternatively, the compounds of formula (I) may be effective in treating patients infected with
pathogenic bacteria selected from S. aureus, MRSA and
Enterococcus faecalis.