monensin

Monensin is a polyether antibiotic and ionophore produced by the bacterium Streptomyces cinnamonensis. It is primarily used as a veterinary drug in ruminant animal feeds to prevent coccidiosis in poultry and as a growth promoter in cattle. Monensin acts by forming complexes with monovalent cations (such as Na+, K+, Li+), facilitating their transport across lipid membranes. This disrupts normal ion gradients, particularly functioning as an Na+/H+ antiporter, which alters microbial activity in the rumen and inhibits protozoal growth. Its use increases feed efficiency and milk production efficiency in dairy cows[1][2][3][4][5]. Monensin also blocks intracellular protein transport and has been used experimentally to block Golgi transport[4]. It was the first polyether antibiotic whose structure was elucidated.

Brand names

Rumensin

Other names

monensin AMonensin sodium