Evaluation of the Association Metformin: Plantago ovata Husk in Diabetic Rabbits.

In this experimental study we have investigated whether the inclusion of the dietary fiber Plantago ovata husk could be recommended as coadjuvant in treatments with oral hypoglycemic drugs. We evaluated the use of Plantago ovata husk-metformin association in diabetic rabbits by determining its effects on glucose and insulin concentrations. Six groups of 6 rabbits were used. Groups 1 to 3 were fed with standard chow and groups 4 to 6 with chow supplemented with Plantago ovata husk (3.5 mg/kg/day). Two groups (numbers 1 and 4) were used as controls (receiving standard or supplemented chow), two groups (numbers 2 and 5) received metformin orally, and the other two (numbers 3 and 6) were treated orally with metformin and psyllium. Plasma glucose concentrations were lower in groups fed with fiber-supplemented chow whereas insulin levels showed important interindividual variations. Glucose pharmacokinetics parameters showed significant differences in Cmax and t(max) in relation to fiber intake. Insulin pharmacokinetics parameters after treatment with oral metformin showed an important increase in Cmax, AUC, and t(max) in animals fed with fiber. We conclude that Plantago ovata husk intake can contribute to the oral antihyperglycemic treatment of type 2 diabetes.

Enrofloxacin: pharmacokinetics and metabolism in domestic animal species.

Enrofloxacin is a fluorquinolone exclusively developed for use in veterinary medicine (1980). The kinetics of enrofloxacin are characterized, in general terms, by high bioavailability in most species and rapid absorption after IM, SC or oral administration. However, several studies reported that enrofloxacin showed low bioavailability after oral administration in ruminants. This drug has a broad distribution in the organism, excellent tissue penetration and long serum half-life. Also, enrofloxacin is characterized by a low host toxicity, a broad antibacterial spectrum and high bactericidal activity against major pathogenic bacteria (both Gram-positive and Gram-negative), and intracellular organisms found in diseased animals. The kinetics vary according to the route of administration, formulation, animal species, age, body condition, and physiological status, all of which contribute to differences in drug efficacy. The pharmacokinetic properties of drugs are closely related to their pharmacological efficiency, so it is important to know their behavior in each species that is used. This article reviews the pharmacokinetics of enrofloxacin in several domestic animal species.

Tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders.

OBJECTIVE: To determine the tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders by measuring its concentration at various sample collection sites. SAMPLE: 26 udders (obtained following euthanasia) from 26 healthy lactating sheep. PROCEDURES: For each isolated udder, 1 mammary gland was perfused with warmed, gassed Tyrode solution. Enrofloxacin (1 g of enrofloxacin/5 g of ointment) was administered into the perfused gland via the intramammary route or systemically via the perfusion fluid (equivalent to a dose of 5 mg/kg). Samples of the perfusate were obtained every 30 minutes for 180 minutes; glandular tissue samples were obtained at 2, 4, 6, and 8 cm from the teat base after 180 minutes. The enrofloxacin content of the perfusate and tissue samples was analyzed via high-performance liquid chromatography with UV detection. RESULTS: After intramammary administration, maximun perfusate enrofloxacin concentration was detected at 180 minutes and, at this time, mean tissue enrofloxacin concentration was detected and mean tissue enrofloxacin concentration was 123.80, 54.48, 36.72, and 26.42 µg/g of tissue at 2, 4, 6, and 8 cm from the teat base, respectively. Following systemic administration, perfusate enrofloxacin concentration decreased with time and, at 180 minutes, tissue enrofloxacin concentrations ranged from 40.38 to 35.58 µg/g of tissue. CONCLUSIONS AND CLINICAL RELEVANCE: By 180 minutes after administration via the intramammary or systemic route in isolated perfused sheep mammary glands, mean tissue concentration of enrofloxacin was greater than the minimum inhibitory concentration required to inhibit growth of 90% of many common mastitis pathogens in sheep. Use of either route of administration (or in combination) appears suitable for the treatment of acute mastitis in sheep.

Pharmacokinetic behavior of doxycycline after intramuscular injection in sheep.

OBJECTIVE: To determine the pharmacokinetics of a commercial formulation of doxycycline hyclate after IM administration of a single dose to sheep. ANIMALS: 11 healthy domestic sheep. PROCEDURES: For each sheep, doxycycline was administered as a single dose of 20 mg/kg, IM. Blood samples were obtained prior to and for 84 hours after doxycycline administration. Plasma concentrations of doxycycline were determined via high-performance liquid chromatography with UV detection. Pharmacokinetic data were analyzed with noncompartmental methods. RESULTS: Mean ± SD values for pharmacokinetic parameters included maximum plasma concentration (2.792 ± 0.791 µg/mL), time to reach maximum plasma concentration (0.856 ± 0.472 hours), mean residence time (91.1 ± 40.78 hours), elimination half-life (77.88 ± 28.45 hours), and area under the curve (65.67 ± 9.877 µg•h/mL). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that doxycycline had prolonged absorption and elimination in sheep after IM administration. A daily dose of 20 mg/kg would be sufficient to reach effective plasma concentrations against Chlamydia spp (minimum inhibitory concentration, 0.008 to 0.031 µg/mL) and Staphylococcus aureus (minimum inhibitory concentration, 0.12 µg/mL). Doxycycline administered IM could be an option for therapeutic use in sheep, although further studies are needed.

A review of the pharmacological interactions of ivermectin in several animal species.

The antiparasitic activity of ivermectin depends on the presence of an active drug concentration at the site of parasites location for an adapted length of time. Ivermectin interactions with another concurrently administered drug can occur. Concomitant administration of some drugs can increase the bioavailability of simultaneously administered ivermectin. This can, in some cases, become a useful pharmacological strategy to improve its antiparasitic efficacy and to delay the development of resistance in livestock or, in other cases, lead to adverse drug reactions and toxicities. On the other hand, other interactions can result in lower levels of this drug, determining that moderate resistant residual populations of the parasites may persist to contaminate pastures. The characterisation of ivermectin interactions can be used to predict and optimise the value of the parasiticide effects. This article reviews the pharmacological interactions of ivermectin in several domestic animal species.

The pharmacokinetics and interactions of ivermectin in humans--a mini-review.

Ivermectin is an antiparasitic drug with a broad spectrum of activity, high efficacy as well as a wide margin of safety. Since 1987, this compound has a widespread use in veterinary medicine and it use has been extended in humans. Here we present a brief review of the information available regarding the pharmacokinetics and interactions of ivermectin in humans. Awareness of these characteristics could improve the clinical efficacy of Ivermectin. All Authors declare that they do not have any Conflict of interest and that the work is original. All Authors agree that the contents of the manuscript are confidential and will not be copyrighted, submitted, or published elsewhere (including the Internet), in any language, while acceptance by the Journal is under consideration.