ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00359.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A computer method for calculation of the pharmacokinetic parameters of drugs after multiple dosing is described. It is shown that the program can be used to calculate the pharmacokinetic parameters of sulphadimethoxine in pigs and rabbits. The program can be used in calculations of kinetic parameters even in cases where few blood samples are taken. This method for the calculation of pharmacokinetic parameters after repetitive dosing as a new approach in an endeavour to obtain more useful pharmacokinetic parameters is discussed.

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00360.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The pharmacokinetics of the two active anti‐inflammatory compounds, isopropylaminophenazone and phenylbutazone, were investigated in the horse. Therapeutic intravenous doses of 12 mg/kg body weight and 6 mg/kg body weight, respectively, were given separately and as a combination to five horses. Blood concentrations were described by two‐compartment kinetics. Significantly lower total clearances, unchanged volumes of distribution, and hence significantly higher elimination half‐lives were found for both substances when administered as a combination. It is possible that the hydroxylated metabolites of the substances are responsible for the presumed metabolic interfe

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00361.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

As part of a general study of the pharmacokinetics of drugs in the ruminant animal, the absorption and distribution kinetics of meclofenamic acid between the gastro‐intestinal tract and plasma of sheep and cattle were investigated. Meclofenamic acid is a non‐steroidal anti‐inflammatory drug which has been shown to possess anti‐anaphylactic activity in cattle (Aitken&Sanford, 1969; 1972; Wells, Eyre&Lumsden, 1973) and sheep (Alexander, Eyre, Head&Sanford, 1970) and although marketed only for the horse in the United Kingdom (Arquel, Warner‐Lambert) is known to be used in ruminant animals as an anti‐inflammatory drug, for its inhibitory effects on prostaglandin synthesis (Smith G. G. A. 1977, personal communication) and for its anti‐pyretic action (Van Miert, Van der Wal‐Komproe&Van Duin, 1977). The aims of the study were first to evaluate the contribution of reticular (oesophageal) groove closure in directing orally administered drug directly to the abomasum and to assess the rate of absorption through the ruminal epithelium. Second, since Aitken&Sanford (1975) have described the plasma levels of meclofenamate after administration of sodium meclofenamate to cattle by the oral, intravenous and intra‐ruminal routes, it was decided to complement their study and to measure the plasma levels after intra‐muscular injection of sodium meclofenamate. This route is more convenient in cattle than the oral and intravenous routes examined by them. Lastly, the biphasic pattern of plasma levels of meclofenamate observed by Aitken&Sanford (1975) following oral administration of sodium meclofenamate to cattle was further examined using weaned and unweaned calves in an attempt to confirm their view that some of the drug is delivered to the abomasum directly, by‐passing the rumen, by closure of

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00362.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

On five separate occasions, five adult cats were dosed orally with 100 mg chloramphenicol tablets or chloramphenicol palmitate suspension. Each preparation was given once when the cats were fasted and once when fedad lib.In addition, fasted cats were given the tablet preparation on one occasion with 10 ml water orally immediately afterwards. Chloramphenicol concentrations were determined at intervals after dosing, and all urine passed in 24 h after dosing was collected for chloramphenicol assay. The initial plasma antibiotic concentrations were lower with chloramphenicol palmitate suspension than with chloramphenicol tablets, and the bioavailability of chloramphenicol from the palmitate ester was especially poor in starved cats. Chloramphenicol palmitate may thus be undesirable for antimicrobial therapy in inappetent cats. Food and fluid did not appear to influence the availability of chloramphenicol from the tablet preparation, although effects on plasma drug concentrations within 1.5 h of dosing would have been missed in this study. A relatively large proportion of an oral dose of chloramphenicol is excreted unchanged in feline urine. Because of the potential toxicity of the drug, chloramphenicol dose rates should be restricted in cats with renal insufficiency or another antibiotic used.

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00363.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Five cats were dosed on five occasions with 20 mg chloramphenicol/kg body weight. The drug was given three times as chloramphenicol sodium succinate (by intravenous, intramuscular and subcutaneous injections) and twice as crystalline chloramphenicol in capsules. Plasma chloramphenicol concentrations were determined at fixed intervals after administration. Parenteral injection of the ester usually produced highest plasma levels at the initial sampling, 0.5 h after dosing. When capsules were given, there was greater variation between cats: highest plasma levels were recorded usually at 0.5‐2 h after dosage but delayed absorption was evident in some cases. There were no statistically significant differences between the different routes with regard to mean plasma antibiotic levels at each sampling or mean area under the curve of plasma level versus time, except that mean plasma levels at 0.5 h were higher with intravenous or intramuscular injection than with oral administratio

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00364.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Pharmacokinetics and urinary excretion of sulphadimidine were determined in sheep and goats following a single intravenous injection (100 mg/kg). The disposition of the drug was described in terms of exponential expression:Cp=Be‐βt. Based on total (free and bound) sulphonamide level in plasma, pseudo‐distribution equilibrium was rapidly attained and the half‐life for elimination was 3.88 ± 0.64 h and 4.00 ± 0.34 h in sheep and goats, respectively. Body clearance, which is the sum of all clearance processes was 88 ± 19 and 55 ± 4 ml/kg/h in sheep and goats. Based on this study a satisfactory intravenous dosage regimen might consist of 100 and 60 mg sulphadimidine/kg body wt for sheep and goats and should be repeated at 12 h intervals. The influence of disease conditions on predicted plasma levels remain to be verified experimentally. Three‐quarters of an intravenously injected dose of sulphadimidine was excreted in the urine of sheep and goats within 24 h of administration. The drug was mainly excreted as free amine while acetylated drug constituted 7 and 8% of total drug content in the urine of sheep and goats,

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00365.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Isolated sheep lung parenchymal strips responded to histamine>carbachol>PGF2a>5‐HT with contractions, and to isoproterenol (Isop), and to large doses of epinephrine (E), norepinephrine (NE) and phenylephrine (PE) with relaxations. PGF2a‐contracted lung strip responded to PGE1and PGE2with relaxation. The strips which were partially contracted to histamine, PGF2a, 5‐HT and carbachol also responded to isop, E and NE with relaxations. Histamine responses were not modified by metiamide (an H2‐receptor antagonist). Mepyramine and atropine selectively antagonized contractions to histamine and carbachol, respectively. After β‐blockade with propranolol, lung strips responded to NE>E>PE>isop with contractions, which were inhibited or reversed by phentolamine and dibenzyline. It is concluded that H1receptors are present in sheep peripheral airway smooth muscles, and that a‐ and β‐adrenoceptors mediate contraction and relaxation, respectively, in sh

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00366.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00367.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Book reviewed in this article:ANIMAL HEALTH PRODUCTS, DESIGN&EVALUATION, Ed. D. C. Monkhouse, G. C. BRANDERDRUGS IN VETERINARY PRACTICE, J. S. Spinelli, L. R. Enos, LLOYD E. DAVISADVERSE RESPONSE TO INTRAVENOUS DRUGS, J. Watkins, A. Milford Ward, A. T. YOXALLPERSPECTIVES IN THE CONTROL OF PARASITIC DISEASE IN ANIMALS IN EUROPESYMPOSIUM OF THE ASSOCITION OF VETERINARIANS IN INDUSTRY, Eds D. W. Jolly, J. M. Sommerville, E.J. L. SOULSBY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1979.tb00368.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY