Topic:Amikacin
Amikacin is an aminoglycoside antibiotic commonly used in equine medicine to treat bacterial infections, particularly those caused by Gram-negative organisms. It operates by inhibiting protein synthesis in bacteria, leading to cell death. Amikacin is often administered to horses for conditions such as septicemia, respiratory infections, and joint infections. Its use is carefully monitored due to the potential for nephrotoxicity and ototoxicity, especially with prolonged treatment. The pharmacokinetics and dosing regimens of amikacin in horses are crucial to maximizing therapeutic efficacy while minimizing adverse effects. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacology, clinical applications, safety, and resistance patterns associated with amikacin in equine health.
Faster perfusate instillation time results in more systemic leakage of amikacin sulfate when performing intravenous regional limb perfusion in horses. To evaluate if a difference in synovial amikacin concentrations exists in the radiocarpal joint (RCJ) following different durations of instillation of an IV regional limb perfusion (IVRLP) perfusate. Methods: 7 healthy horses. Methods: Horses received 2 IVRLPs with 2 g amikacin diluted to 60 mL with 0.9% NaCl via the cephalic vein in a crossover study design with a wash-out period between procedures. Instillation of the perfusate was administered over a 1-minute (technique 1) and 5-minute (technique 5) period. Concentrations of amikacin within the RCJ were measured at time (T) 5, 10, 15, 20, 2...
Antimicrobial susceptibility of Rhodococcus equi strains isolated from foals in Chile. Rhodococcus equi is responsible for foal pneumonia worldwide, with a significant economic impact on the production and breeding of horses. In Chile, the first case was reported in 2000, and since then, its incidence has been increasing. Distinctive characteristics of R. equi as an intracellular pathogen in macrophages, emergence of virulence plasmids encoding surface lipoprotein antigens, and appearance of antibiotic resistance against macrolides and rifampicin have significantly complicated the treatment of R. equi pneumonia in foals. Therefore, in vitro susceptibility studies of first-line a...
Increasing tourniquet number has no effect on amikacin concentration within the radiocarpal joint in horses undergoing intravenous regional limb perfusion. To determine whether IV regional limb perfusion (IVRLP) performed in the cephalic vein with a wide rubber tourniquet (WRT) applied proximal and distal to the carpus results in a higher peak concentration (Cmax) of amikacin in the radiocarpal joint (RCJ), compared with the Cmax for IVRLP using a single WRT proximal to the carpus. Methods: 7 healthy adult horses. Methods: Horses underwent IVRLP using standing sedation with 2 g of amikacin sulfate diluted to 60 mL by use of saline (0.9% NaCl) solution in the cephalic vein with 2 different tourniquet techniques; proximal WRT (P) and proximal and d...
Time required to achieve maximum amikacin concentration in the synovial fluid of the tarsocrural joint following administration of the drug by intravenous regional limb perfusion in horses. To determine the median time to maximum concentration (t) of amikacin in the synovial fluid of the tarsocrural joint following IV regional limb perfusion (IVRLP) of the drug in a saphenous vein of horses. Methods: 7 healthy adult horses. Methods: With each horse sedated and restrained in a standing position, a 10-cm-wide Esmarch tourniquet was applied to a randomly selected hind limb 10 cm proximal to the point of the tarsus. Amikacin sulfate (2 g diluted with saline [0.9% NaCl] solution to a volume of 60 mL) was instilled in the saphenous vein over 3 minutes with a peristaltic pump. Tarsocrur...
Antimicrobial susceptibility patterns of Rhodococcus equi from necropsied foals with rhodococcosis. Mainstay therapy for rhodococcosis in foals is the combination of rifampicin and a macrolide. While emergence of resistance to rifampicin and macrolides has been reported, studies demonstrating the development of resistance to such drugs is limited in necropsied foals with rhodococcosis. In this study, the foal necropsy records between 01/01/2011 and 08/30/2019 were reviewed for culture-positive R. equi with MICs and, whether or not the affected foals received any mainstay dual therapy before their deaths. Resistance to antimicrobials in the R. equi isolates from necropsied foals were then com...
Time required to achieve maximum concentration of amikacin in synovial fluid of the distal interphalangeal joint after intravenous regional limb perfusion in horses. OBJECTIVE To determine the maximum concentration (Cmax) of amikacin and time to Cmax (Tmax) in the distal interphalangeal (DIP) joint in horses after IV regional limb perfusion (IVRLP) by use of the cephalic vein. ANIMALS 9 adult horses. PROCEDURES Horses were sedated and restrained in a standing position and then subjected to IVRLP (2 g of amikacin sulfate diluted to 60 mL with saline [0.9% NaCl] solution) by use of the cephalic vein. A pneumatic tourniquet was placed 10 cm proximal to the accessory carpal bone. Perfusate was instilled with a peristaltic pump over a 3-minute period. Synovial ...
Aerobic uterine isolates and antimicrobial susceptibility in mares with post-partum metritis. The potential for life-threatening complications of metritis requires prompt initiation of antimicrobial treatment, often before microbiological test results are reported. However, published studies to guide first-line antibiotic selection are scarce. Objective: To report the most frequent bacterial species, antimicrobial susceptibility and prevalence of multidrug resistance (MDR) in cases of equine metritis. Methods: Retrospective analysis of uterine bacterial culture and antimicrobial susceptibility test (AST) results from mares with metritis. Methods: Data from uterine culture and AST from ...
Effect of Dose on Intra-Articular Amikacin Sulfate Concentrations Following Intravenous Regional Limb Perfusion in Horses. To compare synovial concentrations of amikacin following intravenous regional limb perfusion (IVRLP) with two different doses, and to compare their ability to reach target concentrations for bacterial isolates from common orthopedic conditions. Methods: Randomized crossover experiment. Methods: Six adult horses. Methods: Horses received IVRLP with 2 and 3 g of amikacin in the cephalic vein of alternate limbs (20 minutes tourniquet application and ≥14 days washout period). Amikacin concentrations were quantified in synovial fluid collected from the middle carpal and metacarpophalangeal joints...
The Effects of Mepivacaine Hydrochloride on Antimicrobial Activity and Mechanical Nociceptive Threshold During Amikacin Sulfate Regional Limb Perfusion in the Horse. To determine the effect of intravenous regional limb perfusion (IVRLP) with a combination of mepivacaine hydrochloride and amikacin sulfate on synovial fluid amikacin sulfate concentration, antimicrobial activity, and mechanical nociceptive threshold (MNT). Methods: Experimental study. Methods: Healthy adult horses (n=9). Methods: One IVRLP treatment was randomly administered by cephalic vein of each limb: amikacin alone (1 g amikacin in 60 mL saline) or amikacin with mepivacaine (1 g amikacin and 500 mg mepivacaine in 60 mL saline). Opposite treatments were repeated after a 24 hour wash-out p...
The Effect of Perfusate Volume on Amikacin Concentration in the Metacarpophalangeal Joint Following Cephalic Regional Limb Perfusion in Standing Horses. To determine the influence of 3 perfusate volumes on amikacin concentration in the metacarpophalangeal joint following cephalic regional limb perfusion (RLP) in standing horses. Methods: Seven healthy horses. Methods: Three perfusate volumes (100, 60, and 30 mL), containing 2 grams of amikacin, were tested during intravenous RLP at the cephalic vein, placing the tourniquet at mid antebrachium, in standing sedated horses. Synovial fluid was collected from the metacarpophalangeal joint before perfusion and at 30 and 120 minutes after perfusion. Serum samples were taken from the jugular vein at t...
Evaluation of 10-minute versus 30-minute tourniquet time for intravenous regional limb perfusion with amikacin sulfate in standing sedated horses. The objective of the article is to determine the synovial fluid concentrations of amikacin sulfate (AS) after performing an intravenous regional limb perfusion (IVRLP) with the tourniquet in place for 10 minutes and compare this with 30 minutes. This is a randomised crossover experimental design. Animals were seven healthy adult horses. Horses underwent two IVRLP procedures in a randomised, crossover design. The horses received IVRLP with 2 g AS diluted to 60 ml using 0.9% saline in the cephalic vein of alternate limbs with the tourniquet in place for either 10 or 30 minutes, with a ...
The Effect of Intravenous Regional Perfusion of the Distal Limb With Amikacin Sulfate on Wounds Healing by Second Intention in Horses. To compare the gross and histological effects of intravenous regional limb perfusion (IVRLP) using amikacin sulfate on second intention healing of distal limb wounds in adult horses with healing in untreated wounds. Methods: In vivo experimental study. Methods: Adult horses (n = 7). Methods: Two full thickness wounds (2.5 × 2.5 cm) were created aseptically on the dorsal aspect of each metacarpus and maintained under sterile bandages. One forelimb was randomly selected from each horse for IVRLP on days 2, 3, and 4 post-wounding. Sequential biopsies were taken from 1 wound on each limb to evalu...
Accumulation of amikacin in synovial fluid after regional limb perfusion of amikacin sulfate alone and in combination with ticarcillin/clavulanate in horses. To determine the effect of regional limb perfusion (RLP) with amikacin sulfate alone and in combination with ticarcillin/clavulanate on synovial fluid concentration and antimicrobial activity of amikacin. Methods: Experimental study. Methods: RLP with amikacin alone (A; 2.5 g) or amikacin and ticarcillin/clavulanate (AT; 2.5 g amikacin, 7 g ticarcillin/clavulanate) was performed with a tourniquet placed at mid-antebrachium in standing, sedated horses. Perfusate blood was collected immediately after injection and again before tourniquet release. Blood from the jugular vein was collected before ...
Mutant prevention concentration and mutant selection window for 10 antimicrobial agents against Rhodococcus equi. The objectives of this study were to determine the mutant prevention concentration (MPC), time above the MPC and mutant selection window for 10 antimicrobial agents against Rhodococcus equi and to determine if the combination of a macrolide with rifampin would decrease emergence of resistant mutants. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, amikacin, gentamicin, enrofloxacin, vancomycin, imipenem, and doxycycline) were selected based on in vitro activity and frequency of use in foals or people infected with R. equi. Each antimicrobial agent or co...
In vitro synergy, pharmacodynamics, and postantibiotic effect of 11 antimicrobial agents against Rhodococcus equi. There are no studies investigating interactions between clarithromycin or azithromycin and rifampin or other commonly used antimicrobial agents against virulent isolates of Rhodococcus equi. In addition, there is no published data on the postantibiotic effects (PAEs) and pharmacodynamics properties of antimicrobial agents against R. equi. The objectives were to assess in vitro interactions, pharmacodynamics, and PAEs of 11 antimicrobial agents belonging to various antimicrobial classes against R. equi. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, ami...
Evaluation of regional limb perfusion with amikacin using the saphenous, cephalic, and palmar digital veins in standing horses. Previous studies have shown that regional limb perfusion (RLP) using the palmar digital (PD) vein delivers therapeutic concentration of amikacin to the distal limb. Our hypothesis was that using the cephalic and saphenous veins for RLP will enable delivery of therapeutic concentrations of amikacin to the distal limb. Nineteen healthy horses participated in the study. The cephalic, saphenous, or PD vein was used to perfuse the limb with amikacin. Two grams of amikacin was used for RLP using the saphenous and the cephalic veins, and one gram was used in the PD vein. Synovial samples were collect...
Effect of experimentally induced synovitis on amikacin concentrations after intravenous regional limb perfusion. To determine the effects of experimentally induced synovitis of the radiocarpal joint on the intra-articular pharmacokinetics and pharmacodynamics of amikacin after intravenous regional limb perfusion (IVRLP). Methods: Randomized crossover experimental design. Methods: Adult horses (n = 8). Methods: Horses were randomly assigned into 2 trials: synovitis and no-synovitis. Radiocarpal joint synovitis was induced with lipopolysaccharide 6 hours before IVRLP. IVRLP (5-mg/kg amikacin qs 60 mL) was performed with a pneumatic tourniquet under general anesthesia. Synovial fluid was obtained before and...
Comparison of two tourniquets and determination of amikacin sulfate concentrations after metacarpophalangeal joint lavage performed simultaneously with intravenous regional limb perfusion in horses. To determine whether joint lavage performed simultaneously with IV regional limb perfusion (IVRLP) reduces the effectiveness of IVRLP and to compare 2 types of tourniquets used for this procedure in horses. Methods: 11 adult horses. Methods: 2 groups of 6 horses were tested by use of a pneumatic or an Esmarch tourniquet (1 horse was tested twice [once in each group]). Standing IVRLP with amikacin (500 mg) was performed for 30 minutes. Simultaneously, the metacarpophalangeal joint was lavaged with 2 L of lactated Ringer's solution and the egress fluids were collected. Samples of the distal inte...
Pharmacokinetics of amikacin in plasma and selected body fluids of healthy horses after a single intravenous dose. No studies have determined the pharmacokinetics of low-dose amikacin in the mature horse. Objective: To determine if a single i.v. dose of amikacin (10 mg/kg bwt) will reach therapeutic concentrations in plasma, synovial, peritoneal and interstitial fluid of mature horses (n=6). Methods: Drug concentrations of amikacin were measured across time in mature horses (n=6); plasma, synovial, peritoneal and interstitial fluid were collected after a single i.v. dose of amikacin (10 mg/kg bwt). Results: The mean±s.d. of selected parameters were: extrapolated plasma concentration of amikacin at time ze...
Effect of topical application of 1% diclofenac sodium liposomal cream on inflammation in healthy horses undergoing intravenous regional limb perfusion with amikacin sulfate. To determine whether topical application of 1% diclofenac sodium cream would decrease inflammation at sites of IV regional limb perfusion (IVRLP) in healthy horses. Methods: 6 healthy adult horses (12 forelimbs). Methods: Bilateral IVRLP with 2.5 g of amikacin sulfate was performed twice in each horse, with 24 hours between each session. Horses were treated with topical 1% diclofenac liposomal cream (treated limbs) or a placebo cream (control limbs). All injection sites were evaluated before the first IVRLP session and 24 hours after the second session by means of ultrasonographic examination ...
Association of Stenotrophomonas maltophilia infection with lower airway disease in the horse: a retrospective case series. Stenotrophomonas maltophilia is being reported with increasing frequency as a human nosocomial pathogen, especially among immuno-compromised patients. To the authors' knowledge, this pathogen has not previously been associated with lower airway disease in the horse. In this paper the clinical findings, laboratory diagnosis and response to treatment of seven cases of respiratory infection with S. maltophilia in horses, presented at three equine referral hospitals in Denmark in 2007, are described. In all cases there was a clinical history of chronic coughing and abundant mucopurulent exudate wa...
In vitro and in vivo evaluation of ferric-hyaluronate implants for delivery of amikacin sulfate to the tarsocrural joint of horses. To assess the antimicrobial elution characteristics, toxicity, and antimicrobial activity of amikacin-impregnated ferric-hyaluronate implants (AI-FeHAI) for amikacin delivery to the tarsocrural joint of horses. Methods: Experimental study. Methods: AI-FeHAI implants, equine cartilage, and synovium, and horses (n=6). Methods: In vitro study: Five AI-FeHAI were placed in saline solution with daily replacement until implant degradation. Eluent was tested for amikacin concentration and bioactivity. Synovial and cartilage explants were incubated in the presence or absence of AI-FeHAI for 72 hours a...
Effect of intrathecal amikacin administration and repeated centesis on digital flexor tendon sheath synovial fluid in horses. To determine the effect of intrathecal amikacin administration and repeated tenovaginocentesis on the total nucleated cell count (TNCC), total protein (TP) concentration and cytologic characteristics of synovial fluid of the equine digital flexor tendon sheath (DFTS). Methods: Randomized, cross-over experimental design. Methods: Adult horses (n=8). Methods: Synovial fluid was aseptically collected from the DFTS and either 1 mL amikacin sulfate (250 mg/mL) or lactated Ringer's solution (LRS) was injected into the DFTS. Serial synovial fluid samples were obtained at 0, 12, 24, 48, and 72 hours. ...
Pharmacokinetics and pharmacodynamics of enrofloxacin and a low dose of amikacin administered via regional intravenous limb perfusion in standing horses. To evaluate the pharmacokinetic-pharmacodynamic parameters of enrofloxacin and a low dose of amikacin administered via regional IV limb perfusion (RILP) in standing horses. Methods: 14 adult horses. Methods: Standing horses (7 horses/group) received either enrofloxacin (1.5 mg/kg) or amikacin (250 mg) via RILP (involving tourniquet application) in 1 forelimb. Samples of interstitial fluid (collected via implanted capillary ultrafiltration devices) from the bone marrow (BMIF) of the third metacarpal bone and overlying subcutaneous tissues (STIF), blood, and synovial fluid of the radiocarpal joi...
Pharmacokinetics of a high dose of amikacin administered at extended intervals to neonatal foals. To determine disposition kinetics of amikacin in neonatal foals administered high doses at extended intervals. Methods: 7 neonatal foals. Methods: Amikacin was administered (21 mg/kg, i.v., q 24 h) for 10 days. On days 1, 5, and 10, serial plasma samples were obtained for measurement of amikacin concentrations and determination of pharmacokinetics. Results: Mean +/- SD peak plasma concentrations of amikacin extrapolated to time 0 were 103.1 +/- 23.4, 102.9 +/- 9.8, and 120.7 +/- 17.9 microg/mL on days 1, 5, and 10, respectively. Plasma concentrations at 1 hour were 37.5 +/- 6.7, 32.9 +/- 2.6, ...
Comparison of intraosseous or intravenous infusion for delivery of amikacin sulfate to the tibiotarsal joint of horses. To establish the route of infusion (IV or intraosseous) that results in the highest concentration of amikacin in the synovial fluid of the tibiotarsal joint and determine the duration of peak concentrations. Methods: 21 horses. Methods: Regional perfusion of a limb on 15 horses was performed. Amikacin sulfate was infused into the saphenous vein or via intraosseous infusion into the distal portion of the tibia (1 g in 56 ml of lactated Ringer's solution) or proximal portion of the metatarsus (1 g of amikacin in 26 ml of lactated Ringer's solution). Amikacin concentrations were measured in seque...
Comparison of 2 techniques for regional antibiotic delivery to the equine forelimb: intraosseous perfusion vs. intravenous perfusion. The purpose of this study was to compare the synovial fluid concentrations and pharmacokinetics of amikacin in the equine limb distal to the carpus following intraosseous and intravenous regional perfusion. The front limbs of 6 horses were randomly assigned to either intraosseous or intravenous perfusion. A tourniquet was placed distal to each carpus and the limb perfused with 500 mg of amikacin. Systemic blood samples and synovial fluid samples were collected over 70 min from the distal interphalangeal (DIP) joint, metacarpophalangeal joint, and digital flexor sheath. The tourniquet was remov...