TIAMULIN

Chemistry - A semisynthetic diterpene-class antibiotic derived from pleuromulin, tiamulin isavailable commercially for oral use as the hydrogen fumurate salt. It occurs as white to yellow, crystalline powder with a faint but characteristic odor. Approximately 60 mg of the drug are solublein 1 ml of water.

Storage, Stability, Compatibility

Protect from moisture; store in a dry place. In unopenedpackets, the powder is stable for up to 5 years. Fresh solutions should be prepared daily whenusing clinically.

Pharmacology - TIAMULIN

Tiamulin is usually a bacteriostatic antibiotic, but can be bactericidal in very highconcentrations against susceptible organisms. The drug acts by binding to the 50S ribosomalsubunit, thereby inhibiting bacterial protein synthesis.
Tiamulin has good activity against many gram positive cocci, including most Staphylococci and Streptococci (not group D streps). It also has good activity against Mycoplasma and spirochetes.
With the exception of Haemophilus sp. and some E. coli and Klebsiella strains, the drug's activityis quite poor against gram negative organisms.
Uses, Indications - Tiamulin is approved for use in swine to treat pneumonia caused by susceptiblestrains of Haemophilus pleuropneumoniae and swine dysentery caused by Treponema hyodysenteriae. As a feed additive it also used to cause increased weight gain in swine.

Pharmacokinetics - TIAMULIN

Tiamulin is well absorbed orally by swine. Approximately 85% of a dose isabsorbed and peak levels occur between 2-4 hours after a single oral dose. Tiamulin is apparentlywell distributed, with highest levels found in the lungs.
Tiamulin is extensively metabolized to over 20 metabolites, some having antibacterial activity.
Approximately 30% of these metabolites are excreted in the urine with the remainder excreted in thefeces.

Contraindications, Precautions, Reproductive Safety

Tiamulin should not be administered toanimals having access to feeds containing polyether ionophores (e.g., monensin, lasalocid, narasin, or salinomycin) as adverse reactions may occur. Not for use in swine over 250 pounds.
Teratogenicity studies done in rodents demonstrated no teratogenic effects at doses up to 300mg/kg. The manufacturer has concluded that the drug is not tumorigenic, carcinogenic, teratogenicor mutagenic.

Adverse Effects, Warnings

Adverse effects occurring with this drug at usual doses are considered unlikely. Rarely, redness of the skin, primarily over the ham and underline, has been observed.
It is recommended to discontinue the medication, provide clean drinking water and hose down thearea or move affected animals to clean pens.

Overdosage, Acute Toxicity

Oral overdoses in pigs may cause transient salivation, vomiting and CNS depression (calming effect). Discontinue drug and treat symptomatically and supportively ifnecessary.

Drug Interactions

Tiamulin should not be administered to animals having access to feedscontaining polyether ionophores (e.g., monensin, lasalocid, narasin, or salinomycin) asadverse reactions may occur. Although not confirmed with this drug, concomitant use with otherantibiotics that bind to the 50S ribosome (e.g., clindamycin, lincomycin, erythromycin, tylosin) could lead to decreased efficacy due to competition at the site of action.