Intramuscular administration in horses involves the injection of medications directly into the muscle tissue. This method is commonly used for delivering vaccines, antibiotics, and other therapeutic agents. The technique requires knowledge of equine anatomy to ensure the injection is placed in the correct location, such as the neck or hindquarters, to minimize discomfort and avoid complications. Proper intramuscular administration can facilitate the absorption of medications into the bloodstream, allowing for effective therapeutic interventions. This page compiles peer-reviewed research studies and scholarly articles that explore the techniques, benefits, and potential complications associated with intramuscular administration in equine practice.
Dow SM, Wilson AM, Goodship AE.Horses with acute injuries of the superficial digital flexor tendon were treated with a course of seven intramuscular injections of 500 mg of polysulphated glycosaminoglycan at four-day intervals. Clinical assessments of the lesions were made by a veterinary surgeon at the time of each injection and 14 and 28 days after the last injection. A total of 150 courses of the drug were administered and adequately completed assessment forms were returned for 80 cases. Long-term follow-up data were obtained for 19 cases. The subjective assessments by the veterinary surgeons showed that in 80 per cent o...
Aramaki S, Ishidaka O, Suzuki E, Momose A, Umemura K.In a doping test for racing horses, it is useful for the elucidation of the illegal use of drugs if one can estimate the time at which the detected drug was administered. In order to estimate the time which has elapsed after the administration of caffeine (CA) into horses, the ratios of concentration for the respective metabolites to the unchanged CA in the plasma or the urine were determined. These ratios have been known to be independent of the dose of CA. The relationship between [plasma or urinary concentration of a metabolite]/ [plasma or urinary concentration of the unchanged drug] and t...
Milne EM, Doxey DL, Woodman MP, Cí·¯ord D, Pearson RA.A clinical trial was carried out to determine the effect of cisapride on rate of passage of digesta and clinical parameters in horses with chronic grass sickness. Sixteen horses were given intramuscular cisapride (0.1 mg kg-1 three times daily) (group I), and 15 received oral cisapride (0.8 mg kg-1 three times daily) (group O). A liquid-phase marker (cobalt-EDTA) and a solid-phase marker (polystyrene pellets) were given by stomach tube at the beginning of each of three consecutive 7 day periods, i.e., before, during and after cisapride therapy. Seven horses in each group completed the rate of ...
Klee S, Nürnberger MC, Keller H, Ungemach FR.A therapeutical dose of kanamycin was tested intravenously and intramuscularly in four normal standardbreds and plasma concentrations were measured over a 12 hour period. Plasma levels exceeded a minimum inhibitory concentration of 4 micrograms/ml within only 15 minutes for 8 hours both after i.v. and i.m. injection. Kanamycin revealed a mean plasma half life of 2.3 hours. Bioavailability of an intramuscular dose was about 76%. The pharmacokinetic parameters demonstrate the rapid onset of antibacterial plasma levels of the test compound. A dose regimen for horses of two times daily 5 mg/kg bod...
McKellar QA, Varma KJ.Florfenicol was administered to horses and ponies at a dose rate of 22 mg/kg bwt by i.v., i.m. and oral routes. Following i.v. administration it had an elimination half-life of 1.8 ± 0.9 h, a body clearance of 0.4 ± 0.11/h.kg and a volume of distribution at steady-state of 0.7 ± 0.2 1/kg. It was highly bioavailable following i.m. (81%) and oral (83%) administration. Less than 15% of the administered dose was excreted unchanged in the urine during the 30 h following administration. Animals treated with florfenicol had elevated bilirubin concentrations. Florfenicol was well tolerated by anima...
Orsini JA, Park MI, Spencer PA.Concentrations of amikacin in endometrial tissue and plasma were studied in mares in estrus after intrauterine infusion of 1.0 or 2.0 g once a day for 3 consecutive d, and after 9.7 or 14.5 mg/kg body weight (BW) had been injected intramuscularly once a day for 3 consecutive d to determine concentrations of amikacin sulfate in plasma and endometrial tissues, and whether parenteral administration provides any advantages over intramuscular infusion. No amikacin was detected in serum at the 1.0 g dose. At the infusion dose of 2.0 g once a day, very low levels of serum amikacin were detected at 1 ...
Soraci AL, Mestorino ON, Errecalde JO.The pharmacokinetics and bioavailability of cefoperazone (CPZ) were studied following intravenous (IV) and intramuscular (IM) administration of single doses (30 mg/kg) to horses. Concentrations in serum, urine and synovial fluid samples were measured following IV administration. CPZ concentrations in serum, synovial fluid and spongy bone samples were measured following IM administration. After IV administration a rapid distribution phase (t1/2 (alpha): 4.22 +/- 2.73 min) was followed by a slower elimination phase (t1/2(beta) 0.77 +/- 0.19 h). The apparent volume of distribution was 0.68 +/- 0....
Geor R, Hope E, Lauper L, Piela S, Klassen J, King V, Murphy M.The effects of dexamethasone (0.2 mg/kg of body weight; IV, IM, and PO) and methylprednisolone acetate (120 mg given intra-articularly) on serum osteocalcin and cortisol concentrations were studied in 6 horses. Serum osteocalcin and cortisol concentrations were serially monitored after each treatment. A significant (P < 0.05) decrease in serum osteocalcin and cortisol concentrations was observed from 12 to 24 and 2 to 48 hours, respectively, after IV and IM administrations of dexamethasone. Serum osteocalcin and cortisol concentrations were significantly decreased from 6 to 48 and 3 to 72 h...
Swan GE, Guthrie AJ, Mülders MS, Killeen VM, Nurton JP, Short CR, van den Berg JS.The pharmacokinetics of gentamicin following single and multiple intravenous and intramuscular doses were compared in a two phase, randomised cross-over study in horses. Gentamicin was administered to 6 healthy, conditioned Thoroughbred mares at a dosage of 3.3 mg/kg body weight every 12 hours for 5 intravenous or intramuscular consecutive treatments. Equal numbers of horses were treated by either route during each phase. There was a wash-out period of 5 days between phases. During each phase serial blood samples were collected from each mare immediately before treatment and at 16 intervals fo...
Toutain PL, Lassourd V, Costes G, Alvinerie M, Bret L, Lefebvre HP, Braun JP.The present study was undertaken to measure the weight of muscle destroyed by an intramuscular injection of phenylbutazone (PBZ) in horses. In six horses, CK disposition parameters were evaluated after intravenous (i.v.) and intramuscular (i.m.) administration of a CK horse preparation. The same horses received PBZ, a potentially irritating agent, by i.v. and i.m. (neck and hindquarter) routes. Data were analysed using compartmental approaches and instantaneous CK flux was calculated using a discrete deconvolution method. For a 150 U/kg CK dose, the steady-state volume of distribution was 0.05...
el-Komy AA.The pharmacokinetics of piperacillin (430 mg/kg.b.wt.) and cephapirin (20 mg/kg.b.wt.) were investigated following a single intravenous and intramuscular injection in normal mares. The serum concentration-time curve following a single intravenous injection of both antibiotics obeyed a two-compartment open model. After intravenous dose, piperacillin and cephapirin were transferred from central to peripheral compartment (k12) with values 0.46 and 0.52 h-1, while their passages from peripheral to central compartment (k21) were equal to 0.56 and 0.49 h-1, respectively. The elimination half-lives [...
Bonnaire Y, Dehennin L, Plou P, Toutain PL.A pharmacological dose of a long-acting testosterone ester, testosterone hexahydrobenzoate, was administered intramuscularly to two mares. The time course for some characteristic metabolites in blood and urine was then studied using an analytical method based on gas chromatography-mass spectrometry associated with stable isotope dilution. Among the plasma analytes, testosterone glucuronide was found to be the most adequate indicator for the monitoring of exogenous testosterone up to 2 weeks postadministration if a threshold value of 200 ng/L was applied. In urine, the simultaneous measurement ...
Lavy E, Ziv G, Glickman A.An aqueous solution of norfloxacin nicotinate (NFN) was administered to donkeys (Aquus asinus) intravenously (once at 10 mg/kg), intramuscularly and orally (both routes once at 10 and 20 mg/kg, and for 5 days at 20 mg/kg/day). Blood samples were collected at predetermined times after each treatment and urine was sampled after intravenous drug administration. Serum NFN concentrations were determined by microbiological assay. Intravenous injection of NFN over 45-60 s resulted in seizures, profuse sweating and tachycardia. The intravenous half-life (t1/2 beta) was 209 +/- 36 min, the apparent vol...
Sarasola P, McKellar QA.Ampicillin is an antibiotic commonly administered to horses by both the intramuscular (i.m.) and the intravenous (i.v.) route. Its physicochemical properties restrict its absorption after oral administration and explain its rapid elimination from the body. To prolong the effects of ampicillin in the horse, attempts have been made to alter its elimination and absorption rates. The alteration of urinary pH did not change the plasma disposition of the antibiotic but when probenecid was administered concurrently with ampicillin, a significant reduction of total body clearance was achieved. Ampicil...
Jaglan PS, Roof RD, Yein FS, Arnold TS, Brown SA, Gilbertson TJ.Ceftiofur sodium, a broad spectrum cephalosporin antibiotic approved for veterinary use, is metabolized to desfuroylceftiofur which is conjugated to micro as well as macromolecules. Twelve horses, weighting 442-618 kg, were injected intramuscularly with a single dose of 2.2 mg ceftiofur/kg (1.0 mg/lb) body weight. Blood was collected at various intervals over 24 h after treatment. Three groups of four horses each were euthanized and lungs were collected at 1, 12, and 24 h after treatment. The concentration of desfuroylceftiofur and desfuroylceftiofur conjugates in the plasma and lungs was dete...
Chui YC, Esaw B, Laviolette B.Urine samples collected from a horse after intramuscular administration of 40 mg of azaperone were extracted at pH 10 before and after acid hydrolysis. The extracts were concentrated and analysed by LC-MS-MS. Two N-dealkylated metabolites, N-despyridinylazaperol and N-despyridinylazaperone, and a low concentration of azaperone were detected in the unhydrolysed urine. Six metabolites; hydroxyazaperol, two hydroxyazaperones, azaperol, N-despyridinylazaperol and N-despyridinylazaperone were detected in the hydrolysed urine extracts. Using XAD-2 resin extraction, three glucuronide conjugated azape...
Landuyt J, Delbeke FT, Debackere M.The plasma concentrations of phenylbutazone (PBZ) and its major metabolites, oxyphenbutazone (OPBZ) and gamma-OH-phenylbutazone (OHPBZ) were determined for up to 72 h in six horses, following intravenous (i.v.) and intramuscular (i.m.) administration of 4 g phenylbutazone, 20 ml Phenylarthrite Ventoquinol (Vetoquinol Spécialités Pharmaceutiques Vétérinaires, Magny-Vernois, 70200 Lure, France). After i.v. dosing the plasma disposition was best described by a two-compartment open model. The hydroxylated metabolites OPBZ and OHPBZ were present in detectable concentrations for 72 h and 48 h, r...
Firth EC, Whittem T, Nouws JF.Six adult ponies were injected in the same intramuscular site with kanamycin sulphate (10 mg/kg). Two hours later, arthrocenteses of the right metacarpophalangeal, radio-carpal, intercarpal, tibio-tarsal and metatarsophalangeal joints were performed within 3 minutes. Arthrocenteses of the same joints on the left side were conducted 5 hours later. When expressed as a percentage of plasma drug concentration, differences in synovial fluid drug concentration between the joints sampled at 2 and 5 hours after injection were not detected.
Fubini SL, Boatwright CE, Todhunter RJ, Lust G.Intra-articularly administered, long-acting corticosteroids are a beneficial treatment for many equine joint disorders because they alleviate inflammation and signs of pain, but they also exert detrimental effects on the biochemical composition and morphologic features of articular cartilage. Chondroprotective drugs have been shown to mitigate some of the deleterious effects of intra-articularly administered corticosteroids on articular cartilage of laboratory animals. Twenty-one ponies were assigned at random to receive 1 of 3 treatments in the right middle carpal joint. Group-1 ponies (n = 8...
Cervantes CC, Brown MP, Gronwall R, Merritt K.Each of 5 healthy mares was given 5 consecutive IM injections of ceftiofur sodium (2 mg/kg of body weight; 50 mg/ml) at 12-hour intervals. Ceftiofur concentrations were measured serially in serum, synovial fluid, peritoneal fluid, and urine, and were measured in CSF and endometrial tissue after the fifth dose. Mean elimination rate constant was 0.354 +/- 0.101 h-1 and elimination half-life was 2.49 +/- 0.49 hour. Mean serum ceftiofur concentrations peaked approximately 1 hour after each injection. The highest mean ceftiofur concentration was 5.09 micrograms/ml at 1 hour after the fifth dose fo...
Carli S, Sonzogni O, Villa R, Bignazzi R, Montesissa C.The pharmacokinetic profile of a sulphamonomethoxine-trimethoprim (SMM-TMP) combination was investigated in five horses. The combination was administered intravenously, intramuscularly and orally at a constant dose of 20 mg SMM plus 4 mg TMP kg-1 bodyweight. Following intravenous administration both drugs dispersed rapidly with distribution half-lives of about 12 minutes for SMM and about 18 minutes for TMP. Elimination half-lives for intravenous, intramuscular and oral administration were closely similar, indicating that elimination was independent of administration route. Bioavailability of ...
Mahrt CR.Ceftiofur sodium, a broad-spectrum cephalosporin antibiotic, was evaluated for safe use in horses. Male or female horses were allotted to groups and were given either saline solution (control), or 2.2, 6.6, or 11 mg of an aqueous solution of ceftiofur sodium/kg of body weight/d, IM, for 30 or 31 days. These dosages are expressed in terms of the ceftiofur free acid, and represent 1 to 5 times the proposed therapeutic dosage (2.2 mg/kg/d) administered for 3 times the maximal recommended duration of 10 days. Some of the horses were euthanatized and necropsied on day 31 or 32. The other horses wer...
Uboh CE, Soma LR, Rudy JA, Morgan E, Mengeringhausen K, Sams R.This study was undertaken to determine the applicability of plasma concentration of furosemide and specific gravity (SG) of urine in regulating the use of furosemide administered 4 hours prior to race time in Exercise-Induced Pulmonary Hemorrhage (EIPH) race horses. Nonbleeders (CTL) and certified bleeders (FUR) actively racing in Illinois (IL) and Pennsylvania (PA) were used in the study. Various doses (less than 250, 250, 300, 350, 400 and 500 mg) were administered either as a single intravenous (IV) dose or as a combination (IV-IM) of IV and intramuscular (IM) administrations 4 hours before...
Chapman CB, Courage P, Nielsen IL, Sitaram BR, Huntington PJ.Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penic...
Baggot JD.The route of administration and formulation of the dosage form affect the bioavailability (rate and extent of absorption) of a drug and may thereby influence the intensity and duration of the pharmacological effect. Location of injection site may affect the plasma concentration profile of drugs administered as aqueous suspensions or sustained release parenteral preparations (procaine penicillin G). When absorption influences the rate of elimination ('flip-flop' phenomenon), the apparent half-life of the drug will be increased (cefazolin sodium, i.m.; meclofenamic acid, p.o.). Absorption genera...
Staigmiller RB, Bellows RA, Anderson GB, Seidel GE, Foote WD, Menino AR, Wright RW.Superovulation has been practiced in cattle for more than 50 years but the results have been highly variable. Scientists at six locations compared a horse pituitary extract (HAP) with a single batch of porcine FSH (pFSH) to determine the efficacy of these hormones to induce superovulation and to test for variability in the superovulatory response. Acetone-dried equine pituitaries were suspended in 40% ethanol containing 6% ammonium acetate, and the supernatant was mixed with 2.5 volumes of cold ethanol. The resulting precipitate was washed with cold ether and dried. Total doses of 18 mg of HAP...
Lyons ET, Tolliver SC, Drudge JH, Granstrom DE, Collins SS, Stamper S.The activity of moxidectin was evaluated in 1988 and 1989 against natural infections of internal parasites in 20 critical tests (n = 20 equids) and three controlled tests (n = 20 equids). Two formulations, injectable administered intramuscularly (i.m.) or intraorally (i.o.) and gel i.o., were given at dose rates of 0.2, 0.3 or 0.4 mg kg-1 body weight. For the critical tests (all three dose rates evaluated), removals of second instar Gasterophilus intestinalis were 93-100%, except (89%) for the injectable formulation (i.m.) at 0.2 mg kg-1. Removals of third instar G. intestinalis were 88-100% f...
Stevenson AJ, Weber MP, Todi F, Young L, Beaumier P, Kacew S.Plasma and urinary concentrations of procaine were examined in Standardbred mares after subcutaneous administration of various doses (80 mg to 1600 mg) of procaine hydrochloride. Regardless of dose, peak plasma procaine values occurred within 1 h, but remained detectable in a dose-dependent manner, with procaine present at 1 h with the 80 mg dose and 6 h at the 1600 mg dose. Similarly, peak urinary procaine concentrations were attained within 1.5 to 3 h, irrespective of dose, while detection time was dose-dependent, being 23 h for 80-200 mg doses but as long as 30-54 h with the 1600 mg dose. W...
Hopen LA, Colahan PT, Turner TA, Nixon AJ.Subchondral cyst-like lesions of the cubital joint were diagnosed in 7 horses at the teaching hospital between 1983 and 1987. Diagnosis of the lesions was made by administration of intra-articular local anesthesia and/or radiographically. Initial treatment for all horses consisted of stall rest for 60 to 90 days. In addition, 2 horses were administered sodium hyaluronate intra-articularly, 1 horse was given injections of polysulfated glycosaminoglycans IM, and 1 horse was given phenylbutazone orally. Follow-up information was compiled 6 weeks to 4 years after initial examination. At the time o...
Ensink JM, Klein WR, Barneveld A, Vulto AG, Van Miert AS.Tissue chambers, implanted subcutaneously in ponies, were inoculated with Streptococcus zooepidemicus. The animals received either no antibiotics or one of the following treatments: pivampicillin per os (19.9 mg/kg, equivalent to 15 mg/kg ampicillin, every 12 h) for 7 or 21 days (7 and 5 ponies, respectively), procaine penicillin G intramuscularly (12 mg/kg = 12,000 IU/kg, every 24 h) for 7 days (7 ponies), or ampicillin sodium intravenously (equivalent to 15 mg/ kg ampicillin, every 8 h) for 1 day (5 ponies). Only intravenous administration was started before infection (prophylactically), the...
Parkinson KC, Vanderwall DK, Rigas J, Sweat A.The objective of this study was to determine if intramuscular administration of 60 units of oxytocin once daily for 29 days, regardless of when treatment was initiated during the estrous cycle (i.e., without monitoring estrous behavior and/or detecting ovulation), would induce prolonged corpus luteum (CL) function in cycling mares. Mares were randomly assigned to two groups: (1) saline-treated control (n = 7) and (2) oxytocin-treated (n = 9) subjects. Control mares received 3 cc of saline, and oxytocin-treated mares received 60 units (3 cc) of oxytocin intramuscularly for 29 consecutive d...
Brown MP, Gronwall R, Gossman TB, Houston AE.Six healthy foals, from 4 to 6 days of age, were given a single IM injection of sodium cephapirin (250 mg/ml) at a rate of 20 mg/kg of body weight. Serum concentrations of cephapirin were measured serially over an 8-hour period. The mean peak serum concentration was 21.2 micrograms/ml at 10 minutes. The overall elimination rate constant was 1.06/hr and the elimination half-life was 0.70 hour. The apparent volume of distribution at steady state was 1.06 L/kg and plasma clearance was 1,105 ml/hr/kg.
Brown MP, Stover SM, Kelly RH, Farver TB.Six healthy adult mares were given a single dose of kanamycin sulfate (200 mg/ml) IM at a dosage rate of 5 mg/kg of body weight. Kanamycin concentrations in serum, synovial fluid, peritoneal fluid, and urine were measured serially over a 48-hour period. The mean peak serum kanamycin concentration was 12.55 microgram/ml at 1 hour. Mean peak kanamycin concentrations in synovial fluid and peritoneal fluid were 7.25 microgram/ml and 9.27 microgram/ml at 2 hours and 3 hours, respectively. These concentrations decreased steadily in parallel with serum concentrations and were still measurable at 48 h...
Firth EC, Nouws JF, Klein WR, Driessens F.A pilot study in two ponies showed that the plasma concentrations of intramuscularly administered procaine penicillin were higher if phenylbutazone was administered concurrently. In two other trials, each involving five horses, intravenous sodium penicillin was administered with and without concurrent intravenously injected phenylbutazone, and procaine penicillin was injected intramuscularly with and without oral phenylbutazone. In both cases the plasma concentrations of penicillin were higher when phenylbutazone was given. The pharmacokinetic parameters indicated that the effect was probably ...
MacAllister CG, Perdue BD.Unilateral ectopic ureter was diagnosed by endoscopic examination in an 18-month-old filly examined because of chronic urine dribbling. Intramuscular administration of azosulfamide discolored the urine and enhanced visualization of the ectopic ureter. Endoscopy proved valuable in determining that only one ureter entered the urinary bladder and in locating the ectopic ureter in the ventral portion of the vagina.
Brown MP, Gronwall RR, Houston AE.Six healthy adult horse mares were each given a single injection of sodium cephapirin (20 mg/kg of body weight, IV), and serum cephapirin concentrations were measured serially over a 6-hour period. The mean elimination rate constant was 0.78 hour-1 and the elimination half-life was 0.92 hours. The apparent volume of distribution (at steady state) and the clearance of the drug were estimated at 0.17 L/kg and 598 ml/hour/kg, respectively. Each mare was then given 4 consecutive IM injections of sodium cephapirin (400 mg/ml) at a dosage level of 20 mg/kg. Cephapirin concentrations in serum, synovi...
Frerichs WM.The effect of imidocarb dipropionate [3, 3' bis-(2-imidazolin-2-yl) carbanilide dipropionate] on spermatogenesis in 3 pony stallions was studied. The drug alone had no deleterious effect on spermatogenesis when given intramuscularly 4 times at a dosage level of 4 mg/kg at 72-hour intervals. Hemicastration, with or without subsequent drug treatment, caused almost complete cessation of spermatogenesis 30 days after the operation.
Slone DE, Purohit RC, Ganjam VK, Lowe JL.Three ponies and 1 horse were bilaterally adrenalectomized (BADX). The initial hypoadrenal episode after BADX was reversed with 20 mg of dexamethasone (DXM) IM (n = 2) or 20 mg of triamcinolone (TMC) IM (n = 2). Nine hypoadrenal crises were reversed with 20 mg of DXM given IM (n = 4) or 20 mg of TMC given IM (n = 5). Sodium and chloride retention and potassium excretion were documented based on changes in serum electrolytes and urinary excretion. Eight intact adult horses were randomly assigned to 2 groups to study the effects of a single IM injection of DXM (0.044 mg/kg of body weight) or TMC...
DiPietro JA, Todd KS, Lock TF, McPherron TA.The anthelmintic activity of ivermectin was evaluated in 18 female horses with naturally acquired parasitic infections. Horses were treated once (IM) with vehicle only (n = 6), 200 microgram/kg of body weight (n = 6), and 300 microgram/kg (n = 6). Efficacy of both dosages of ivermectin was greater than 99% against Gasterophilus spp, 100% against Trichostrongylus axei, Habronema muscae, H majus, and Draschia megastoma, 98% to 99% against adult cyathostomes, 86% to 97% against 4th-stage cyathostomes, and 100% against adult large strongyles. Although ivermectin was incomplete in its activity agai...
Mirck MH, van Meurs GK.Seven foals naturally infected with Strongyloides westeri were injected intramuscularly with ivermectin at a dosage rate of 200 mcg per kg body weight. No adverse effects to treatment were observed. Weekly faecal egg counts showed a greater than 99 per cent reduction of S. westeri egg output compared with 7 untreated foals during the 21 days following treatment.
Yi R, Zhao S, Lam G, Sandhu J, Loganathan D, Morrissey B.Cathinone is the principal psychostimulant present in the leaves of khat shrub, which are widely used in East Africa and the Arab peninsula as an amphetamine-like stimulant. Cathinone readily undergoes metabolism in vivo to form less potent cathine and norephedrine as the metabolites. However, the presence of cathine and norephedrine in biological fluids cannot be used as an indicator of cathinone administration. The metabolism of pseudoephedrine and ephedrine, commonly used in cold and allergy medications, also produces cathine and norephedrine, respectively, as the metabolites. Besides, cath...
Robinson MA, Guan F, McDonnell S, Uboh CE, Soma LR.Dermorphin is a μ-opioid receptor-binding peptide that causes both central and peripheral effects following intravenous administration to rats, dogs, and humans and has been identified in postrace horse samples. Ten horses were intravenously and/or intramuscularly administered dermorphin (9.3 ± 1.0 μg/kg), and plasma concentration vs. time data were evaluated using compartmental and noncompartmental analyses. Data from intravenous administrations fit a 2-compartment model best with distribution and elimination half-lives (harmonic mean ± pseudo SD) of 0.09 ± 0.02 and 0.76 ± 0.22 h, respe...
Plotka ED, Seal US, Eagle TC, Asa CS, Tester JR, Siniff DB.Forty-eight newly captured free-ranging feral stallions (Equus caballus) from two different locations and six captive stallions were immobilized using combinations of etorphine hydrochloride, xylazine hydrochloride and atropine sulfate with or without acepromazine. Six animals were immobilized twice, 1 mo apart. The drugs were administered either intramuscularly (n = 13) or intravenously (n = 44). Mean immobilization time (+/- SE) after intravenous (i.v.) injection of etorphine, xylazine and atropine was 55 +/- 4 sec (range 20 to 185 sec) compared to 708 +/- 131 sec (range 390 to 1,140 sec) fo...
Chapman CB, Courage P, Nielsen IL, Sitaram BR, Huntington PJ.Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penic...
McNeal CD, Ryan CA, Berghaus LJ, Credille BC, Lo CP, Fajt VR.Cephalosporin antimicrobials can be utilized for the treatment of sepsis in neonatal foals, particularly when an aminoglycoside is contraindicated. Some cephalosporins, however, are not utilized because of cost, sporadic availability, or uncertainty about efficacy. The plasma disposition of ceftazidime, a third-generation cephalosporin with a broad spectrum of activity against a wide variety of gram-negative bacteria and minimal renal side effects has not been reported in neonatal foals. In this study, the plasma disposition of single intravenous (IV) and intramuscular (IM) doses of ceftazidim...
Pradella GD, Taschetto PM, Duarte CA, da Silva Azevedo M, Góss GC.Adverse drug reactions in horses are rare. The antimicrobials are in the list of the most common drugs associated with reaction in horses. The aim of this report is to describe the clinical presentation of an adverse drug reaction after the intramuscular administration of ceftiofur hydrochloride. A 5-year-old crioulo broodmare at one day postpartum presented signs of difficulty to walk, positive pulse in the four limbs, and heart rate of 80 beats per minute (bpm), with a history of fighting with another mare. The clinical suspicions were rhabdomyolysis and laminitis. Initially a dose of flunix...
Kuroda T, Minamijima Y, Mita H, Tamura N, Fukuda K, Kuwano A, Toutain PL, Sato F.A pharmacokinetics/pharmacodynamics (PK/PD) approach was used to determine the best empirical dosage regimen of cefazolin (CEZ) after intramuscular (IM) administration of CEZ in horses. Seven horses received a single IM or intravenous (IV) administration of CEZ of 5 mg/kg bodyweight (BW) according to a crossover design. CEZ plasma concentrations were measured using LC-MS/MS. The plasma concentrations in these seven horses and those of six other horses obtained in a previous study with an IV CEZ dose of 10 mg/kg were modelled simultaneously using NonLinear Mixed-Effect modelling followed by M...
Jansen BC, Knoetze PC.An intramuscular injection of 8-16 Lf tetanus toxoid in water-in-oil emulsion protected adult horses against tetanus for at least 128 weeks. A booster dose of 8 Lf toxoid in aqueous solution protected them for a further period of at least 3 1/2 years. Colostral immunity protected foals for at least 10 weeks. An intramuscular injection of 8 Lf toxoid in water-in-oil emulsion given to foals from immune dams when they were 10-18 weeks old did not elicit any antibody response. They did respond, however, to a booster injection of 8 Lf toxoid in aqueous solution given 12 weeks after the first dose. ...
Shults T, Kownacki AA, Woods WE, Valentine R, Dougherty J, Tobin T.In horses given (rapid IV) methylphenidate (Ritalin, alpha-phenyl-2-piperidinacetic acid methyl ester; 0.70 mg/kg), plasma concentrations of the drug decreased rapidly at first, with an apparent alpha half-life of about 19 minutes, and then more slowly, with an apparent beta half-life of about 2.4 hours. These data were well fitted by a 2-compartment open model. In blood, about 40% of the methylphenidate present was in the plasma fraction, and of this, about 80% was plasma-protein bound. If given by subcutaneous or IM injection, plasma concentrations of methylphenidate peaked in about 1 hour a...
Fernández-Varón E, Cárceles CM, Marín P, Martos N, Escudero E, Ayala I.To study the pharmacokinetics of difloxacin (5 mg/kg) following IV, IM, and intragastric (IG) administration to healthy horses. Methods: 6 healthy mature horses. Methods: A crossover study design with 3 phases was used (15-day washout periods between treatments). An injectable formulation of difloxacin (5%) was administered IV and IM in single doses (5 mg/kg); for IG administration, an oral solution was prepared and administered via nasogastric tube. Blood samples were collected before and at intervals after each administration. A high-performance liquid chromatography assay with fluorescence ...
Gordon DL, Foreman JH, Connolly SL, Schnelle AN, Fan TM, Barger AM.Acute phase protein (APP) measurement is used to detect inflammation. Intramuscular (IM) injections could cause tissue injury and induce an acute phase response (APR). Objective: To evaluate the effects of IM procaine penicillin G (PPG) injections on APP concentrations in horses. Methods: Prospective longitudinal design. Methods: PPG was administered intramuscularly to six horses, twice daily, for 5 days. Plasma fibrinogen (FIB), serum amyloid A (SAA), haptoglobin (HAP), creatine kinase (CK), and aspartate aminotransferase (AST) were quantified daily for 5 days before the first injection, ...
Weil AB, Keegan RD, Greene SA.To determine whether a low dose of atropine is associated with decreased requirement for cardiovascular supportive treatment in horses given detomidine prior to maintenance of general anesthesia with halothane. Methods: 3 groups of 10 healthy horses. Methods: Detomidine (20 micrograms/kg of body weight, i.m.) was administered to all 30 horses. Then, 10 horses received atropine (0.006 mg/kg, i.v.) 1 hour after detomidine administration, 10 horses received atropine (0.012 mg/kg, i.m.) at the time of detomidine administration, and 10 horses served as a control group. Heart rate was measured prior...