Tiamulin hydrogen fumarate is a semi-synthetic diterpene antimicrobial. The mode of action is by inhibition of ribosomal protein synthesis in sensitive bacteria. It is a bacteriostatic antimicrobial and the following organisms show sensitivity in-vitro:

Brachyspira: Brachyspira hyodysenteriae, B. pilosicoli.

Mycoplasmas: Mycoplasma hyopneumoniae, M. hyorhinis, M. hyosynoviae, Ureaplasma spp.

Gram-positive: Staphylococcus spp., Streptococcus spp., Arcanobacterium pyogenes.

Gram-negative: Pasteurella spp., Klebsiella pneumoniae, Actinobacillus (Haemophilus) spp., Fusobacterium necrophorum, Bacteroides spp., Campylobacter coli, Lawsonia intracellularis.

For the treatment, prevention and control of swine dysentery caused by Brachyspira hyodysenteriae and complicated by Fusobacterium and Bacteroides spp.