Topic:Pharmaceuticals
Pharmaceuticals in equine medicine encompass a wide range of drugs and therapeutic agents used to treat various conditions in horses. These substances include analgesics, anti-inflammatories, antibiotics, sedatives, and anthelmintics, among others. Each class of pharmaceuticals is designed to address specific health issues, such as pain management, infection control, or parasitic infestations. The pharmacokinetics and pharmacodynamics of these drugs can vary significantly between horses and other species, necessitating careful consideration of dosage and administration methods. This page compiles peer-reviewed research studies and scholarly articles that explore the development, efficacy, safety, and regulatory aspects of pharmaceuticals used in equine healthcare.
Influence of furosemide on the detection of flunixin meglumine in horse urine samples. The possibility of false negative results from TLC when a diuretic is administered concomitantly with flunixin was studied. Samples were subjected to solvent extraction from acidic aqueous solutions; duplicate samples were also subjected to alkaline hydrolysis at pH 12.5. The internal standard was flufenamic acid. The quantification of flunixin was performed by HPLC and the results confirmed by GC/MS. The data show that furosemide influences the urinary concentration of flunixin.
The influence of furosemide on plasma elimination and urinary excretion of drugs in standardbred horses. A study of the effects of intravenous administration of either 150 mg or 250 mg of furosemide to standardbred mares pre-treated with other drugs was undertaken to determine whether a unique pattern of drug elimination into urine and from plasma for each compound occurred. Furosemide significantly reduced the plasma concentrations of codeine compared to control 2-6 h after furosemide administration. In contrast, the plasma concentrations of theophylline, phenylbutazone, pentazocine, guaifenesin and flunixin were not markedly altered by furosemide. In the case of acepromazine, clenbuterol and fe...
Veterinary use of ivermectin. Following the development of a unique claim structure encompassing both nematode and arthropod species, ivermectin was first introduced as a veterinary parasiticide in 1981. For cattle(c), sheep(s), horses(h) and pigs(p) injectable(c,s,p), oral(c,s,h) and topical(c) products are available delivering ivermectin at 200 to 500 micrograms/kg. Efficacy extends to nematodes of the gastrointestinal and respiratory tracts, conjunctival sac and soft tissues. Among the arthropod parasites claims have been established for the biting fly Haematobia irritans(c), the screw-worm Chrysomyia bezziana(c), larva...
Pharmacokinetic studies of cimetidine hydrochloride in adult horses. Histamine type II (H2) antagonists inhibit gastric acid secretion and are useful in treating gastric and duodenal ulcer disease. To provide some information on the pharmacokinetics of the H2 antagonist cimetidine, adult horses were given 3.3 mg/kg cimetidine intravenously (iv) or 3.3 and 10 mg/kg orally. Plasma cimetidine concentrations after 3.3 mg/kg orally were too low to measure. Following 3.3 mg/kg iv, cimetidine displayed two-compartment characteristics with a t1/2 of 0.083 +/- 0.039 h and t1/2 of 2.23 +/- 0.64 h. The total body clearance was 0.443 +/- 0.160 litre/h/kg and the mean resid...
High-performance liquid chromatography/tandem mass spectrometry: its use for the identification of stanozolol and its major metabolites in human and equine urine. A screening procedure for the anabolic steroid stanozolol in human and equine urine was developed based on enzymatic hydrolysis, liquid-liquid extraction and reversed-phase liquid chromatography combined on-line with tandem mass spectrometry. The column effluent was introduced into the atmospheric pressure ionization source of a triple-quadrupole mass spectrometer via a heated pneumatic nebulizer liquid chromatograph/mass spectrometer interface. Abundant protonated molecular ions were generated by corona discharge ionization. Confirmation of stanozolol and several of its hydroxylated and dihyd...
Pharmacokinetic disposition of an immediate-release aminophylline and a sustained-release theophylline formulation in the horse. The pharmacokinetic disposition of theophylline was determined by high-performance liquid chromatographic analysis of plasma samples from six healthy, adult horses following the administration of intravenous aminophylline (dosed at 9.94 mg/kg as theophylline), immediate-release aminophylline tablets (dosed at 9.94 mg/kg as theophylline), and sustained-release theophylline tablets (dosed at 20 mg/kg). The elimination rate constant (lambda z), apparent volume of distribution (Vz), and clearance (Cl) determined by compartmental analysis of the intravenous data were 0.07 +/- 0.01 h-1, 0.80 +/- 0.0...
An improved TLC method for the detection of flunixin in equine serum. A method for flunixin detection in equine serum extracts involving thin layer chromatography, spraying the chromatogram with alkaline sodium hypochlorite solution and heating with a detection limit of 50 ng ml-1 is described.
Simultaneous analysis of furosemide and bumetanide in horse plasma using high performance liquid chromatography. A high performance liquid chromatographic method is described for the simultaneous determination of furosemide and bumetanide in horse plasma. The C8 (3 microns) reversed phase column (4.8 x 150 mm) provided clear separation of furosemide and bumetanide with other components present in the horse plasma. The detection limit for both the drugs was 10 ng/mL. Both drugs were stable in plasma (at natural or acidic pH) for up to 24 h. The method is sufficiently sensitive to detect furosemide levels in plasma obtained from horses receiving a therapeutic dose of furosemide.
Extrapyramidal side effects caused by fluphenazine decanoate in a horse. To provide long-term sedation, a horse was given fluphenazine decanoate, a human antipsychotic drug. The horse was progressively agitated and made unusual repetitive motions. Sedation with barbiturates was an effective treatment. This case is not unusual, and the use of fluphenazine by veterinarians in horses as a mild long-acting tranquilizer is not uncommon.
Screening of steroids in horse urine and plasma by using electron impact and chemical ionization gas chromatography-mass spectrometry. Gas chromatography with chemical ionization mass spectrometry and selected-ion monitoring provided a sensitive method for the screening and confirmation of steroids in horse urine and plasma. Chemical ionization mass spectrometry was more sensitive than the electron impact ionization mass spectrometry for most of the steroids except for testosterone, prednisone-metabolite-2 and prednisolone-metabolite-2. The chromatographic conditions used in this study provided clean separation of different natural and synthetic steroids. Approximately 75-85% of the steroids added to plasma and approximately ...
Effects of pharmacological agents on gastrointestinal motility. The control mechanisms of gastrointestinal motility are complex. Extrinsic neurohormonal effects modulate an intrinsic system, often called the "gut brain," composed of nervous and neuropeptide components. To exert pharmacologic influence on GI motility, use is made of agents that mimic the external control system. Agents that stimulate opioid receptors, block adrenoceptors, block or facilitate acetylcholine action, or antagonize the action of prostaglandins are used to effect changes in GI motility. The major indications for pharmacologic intervention are to increase motility in constipation,...
GC/MS confirmatory method for etorphine in horse urine. A highly sensitive procedure for GC/MS determination of etorphine in horse urine is described. This assay provides both specificity and reliability and is particularly well suited for the confirmation of radioimmunoassay screening procedures usually used for etorphine. After solvent extraction and purifications, the etorphine is characterized as a pentafluoroacetic derivative (PFAA) by using mass fragmentography. The detection limit is 0.1 ng/mL in urine; the coefficient of variation of the estimations is 10.9%. The procedure has been validated after on-field administration of 5 to 90 microgra...
Screening and confirmation of drugs in horse urine by using a simple column extraction procedure. A simple and reproducible column (Clean Screen-DAU, copolymeric bonded-phase silica column) extraction procedure has been described for the screening and confirmation of drugs in horse urine. The recovery of drugs by the column extraction was better than or comparable to the recovery by the liquid-liquid extraction, which is commonly used in the equine analytical laboratories. The column extraction provided broad coverage of drugs, separated extracts into three fractions (acidic/neutral, steroids, basic), produced a cleaner extract, and eliminated the need for special liquid-liquid extraction ...
Metabolism and pharmacokinetic studies of propionylpromazine in horses. The propionylpromazine concentrations in plasma after intramuscular administration to horses were determined using gas chromatography with nitrogen-phosphorus detection. After hydrolysis by beta-glucuronidase/arylsulphatase, the parent drug and three metabolites were detected in urine. The metabolites were identified as 2-(1-hydroxypropyl)promazine, 2-(1-propenyl)promazine and 7-hydroxypropionylpromazine by gas chromatography-mass spectrometry. No N-demethylated or sulphoxidated metabolites of propionylpromazine were observed in the horse urine.
Urinary excretion of pentoxifylline and its metabolites by standardbred mares. The urinary excretion of a sustained-release formulation of pentoxifylline was studied in the horse after the oral administration of 4.0 grams of Trental tablets. Urine samples were collected for 24 hours after dosing and analyzed for pentoxifylline and its metabolites using high-performance liquid chromatography coupled with an ultraviolet detector. Six metabolites of pentoxifylline were identified in horse urine in addition to less than 0.2% of unchanged drug. Concomitant use of gas chromatography/mass spectrometry allowed for the elucidation of the chemical structures of the metabolites. Me...
ELISA detection of fentanyl in horse urine and plasma. The prototype of a commercial ELISA test kit designed for fentanyl determination in human urine has been evaluated for screening fentanyl in horse urine and plasma. The measurement of fentanyl after intravenous (2 mg) and intramuscular (0.25 mg) administration in undiluted plasma was not reproducible while accurate quantification of fentanyl in urine greatly depends on the composition of the horse urine. The ELISA assay, however, is simple and could be successfully used for quantitative measurements in diluted urine and for rapid qualitative screening for fentanyl in large numbers of urine sam...