Introduction of Tiamulin fumarate 

Tiamulin hydrogen fumarate (14-deoxy-14 [(2-diethylaminoethyl)-mercapto-acetoxy] mutilin hydrogen fumarate) is a semisynthetic derivative of the diterpene antibiotic pleuromutilin and is effectively used in the treatment of airsacculitis, which is primarily caused by Mycoplasma spp. Infected animals become more susceptible to different viral infections such as infectious bronchitis and Newcastle disease as well as bacterial pathogens, such as Escherichia coli (coli septicemia). This will lead to reduced growth, impaired feed conversion efficiency, and an increased rate of morbidity and mortality.

Commercial Availability of Tiamulin

Tiamulin is available as a crystalline powder with white to yellowish color. It is commercially available in soluble formulations with 45% tiamulin hydrogen fumarate in a lactose carrier, as a 12.5% solution for inclusion in drinking water, and as a medicated feed premix, commonly 2, 10, and 80% strength, and is available in most countries of the world.

In Vitro Susceptibility of Mycoplasma Species Against Tiamulin

One of the predominant indications for the use of tiamulin is to treat mycoplasma infections in poultry. Tiamulin is highly active in vitro against Mycoplasma strains (M. gallisepticum, M. synoviae, M. meleagridis, and M. iowae), Spirochaetes (Brachyspira hyodysenteriae, Brachyspira innocens, B. pilosicoli, B. intermedia), gram-positive bacteria (staphylococci, streptococci, Clostridia, Arcanobacterium spp), but less active against gram-negative bacteria (Pasteurella, Klebsiella, Haemophilus, Fusobacterium, Campylobacter, Bacteroides spp.)

Mode of Action of Tiamulin

Poulsen et al. (2001) reported that tiamulin binds with the rRNA in the peptidyl transferase slot on the ribosome, in which it prevents the correct positioning of the CCA ends of tRNA for peptide transferase and subsequent protein production.

Interaction of Tiamulin with Other Drugs in Farm Animals

Tiamulin hydrogen fumarate is a semisynthetic derivative of the diterpene antibiotic pleuromutilin used in poultry medicine to treat mainly Mycoplasma- and Brachyspira-related diseases. Its use over 30 yr has not generally increased the development of resistance to these pathogens but occasionally resistant isolates are encountered. Tiamulin administered at therapeutic levels is relatively quickly absorbed, metabolized in the liver, and eliminated from the body of the bird after a withdrawal period of 72 h, and as a result, meat products can be safely consumed. A zero withdrawal period for eggs has been granted in several European Union states. When administered with different drugs, tiamulin has been shown to have an enhanced activity with the tetracyclines. There is a strong interaction, even death, with the ionophore anticoccidials monensin, narasin, and salinomycin when tiamulin is used at therapeutic levels, but this is doserelated and low doses do not interact. It is thought to be caused by the preferential metabolism of tiamulin in the liver resulting in a build up of the ionophore leading to clinical signs of overdosage. Tiamulin shows a milder interaction, such as temporary growth depression, with maduramicin and semduramicin but is compatible with lasalocid. Although tiamulin shows small benefits in improving performance in healthy animals, its main production benefit is in the face of infection, as a true therapeutic antibiotic.

References:

[1] K.M.S. ISLAM D. G S B U Klein. The activity and compatibility of the antibiotic tiamulin with other drugs in poultry medicine—A review[J]. Poultry Science, 2009, 88 11: Pages 2353-2359. DOI:10.3382/ps.2009-00257.