lonophores

THE ionophores are a group of antibiotics produced by the fermentation of fungal [i]Streptomyces[/i] species which have activity against some Gram‐positive bacteria, coccidia, [i]Neospora[/i] and [i]Toxoplasma[/i]. The ionophores have a narrow therapeutic index in some species and are incompatible with drugs which interfere with hepatic metabolism. Toxicity is only seen when they are administered at the wrong dose, to the wrong species or together with those products with known interactions. The ionophores are used as growth promoters in cattle and pigs and as coccidiostats in poultry and ruminants. They include maduramicin, monensin, lasalocid, narasin, salinomycin and semduramicin.