Pharmacokinetics of tilmicosin in equine tissues and plasma

Abstract

netics of tilmicosin in equine tissues and plasma. J. vet. Pharmacol. Therap. 31, 66-70.The macrolide antibiotic tilmicosin has potential for treating bacterial respiratory tract infections in horses. A pharmacokinetic study evaluated the disposition of tilmicosin in the horse after oral (4 mg ⁄ kg) or subcutaneous (s.c.) (10 mg ⁄ kg) administration. Tilmicosin was not detected in equine plasma or tissues after oral administration at this dose. With s.c. injection, tilmicosin concentrations reached a maximum concentration of approximately 200 ng ⁄ mL in the plasma of the horses. Tilmicosin concentrations in plasma persisted with a mean residence time (MRT) of 19 h. Maximum tissue residue concentrations (C max ) of tilmicosin measured in equine lung, kidney, liver and muscle tissues after s.c. administration were 2784, 4877, 1398, and 881 ng ⁄ g, respectively. The MRT of tilmicosin in these tissues was approximately 27 h. Subcutaneous administration of tilmicosin resulted in severe reactions at the injection sites.(Paper

Acute toxicity study of tilmicosin-loaded hydrogenated castor oil-solid lipid nanoparticles

“…These results demonstrated that this nanoparticle carrier remarkably reduced the acute toxicity of tilmicosin. The lower transient drug concentration of Til-HCO-SLN could account for the reduction of acute toxicity of tilmicosin [ 7 , 8 ].…”

“…The ineffectiveness of tilmicosin against infections may be related to inadequate therapeutic drug concentrations and/or an insufficient residence time of the antibiotic in the mammary gland [ 5 ]. Repeated administrations and high dose could enhance the clinical efficacy, but high doses of tilmicosin can result in acute cardiac toxicity in cattle and severe reactions at the injection sites such as vascular collapse and transient swelling caused by a transient high drug concentration [ 6 , 7 ]. The severity of the side effects is dose-dependent [ 8 ].…”

Antimicrobial drug concentrations and sampling techniques in the equine lung

“…After oral administration, it was difficult to maintain clinically relevant drug concentrations of trimethoprim in PELF as only half of the total drug concentrations measured in plasma were found in PELF and these depleted rapidly. (Table 3) Homogenised lung tissue Concentrations of tilmicosin in lung homogenates have been studied in foals treated either orally or subcutaneously (SC) (Clark et al, 2008). Tilmicosin was not detectable by HPLC in serum or tissues after oral dosing.…”

Donkey Internal Medicine—Part II: Cardiovascular, Respiratory, Neurologic, Urinary, Ophthalmic, Dermatology, and Musculoskeletal Disorders

“…Cardiotoxicity of several antibiotics is widely known in donkeys. An example is tilmicosin, a macrolide commonly used in respiratory diseases in some species [22]. Doses used in horses (10 mg/kg) have been shown to induce transient and short-lasting changes in cardiac function and indexes measured by echocardiography in donkeys [23].…”