摘要:

Soback, S., Bor, A., Kurtz, B., Paz, R.&Ziv, G. Clavulanate‐potentiated amoxycillin:in vitroantibacterial activity and oral bioavailability in calves.J. vet. Pharmacol. Therap.10, 105–113.The minimal inhibitory concentrations (MIC) of amoxycillin and clavulanate‐potentiated amoxycillin (amoxycillinxlavulanic acid, 4:1 by weight) were compared for 171Salmonella, 170Escherichia coli, and 32Pasteurellaisolates recovered from infected neonatal calves. In the presence of clavulanic acid, the MIC of amoxycillin was reduced to levels ≥ 12.5 μg/ml for all theSalmonellagroup B, all thePasteurella, and for 12 out of the 44E.coliisolates which were resistant to amoxycillin (MIC ≥ 100.0 μg/ml). For isolates sensitive to amoxycillin (MIC ≥ 1.56 μg/ml) there was no change in MIC values in the presence of clavulanic acid. A small proportionof SalmonellaandE. coliisolates were resistant to clavulanate‐potentiated amoxycillin. In a cross‐over trial involving 10 preruminant (2 weeks old) calves, amoxycillin trihydrate and clavulanate‐potentiated amoxycillin were administered orally at 10 mg/kg. An analysis of serum amoxycillin level data showed that the pharmacokinetic parameterst½ab,Cmax,t½β, AUC, Cpo, andf(estimated drug absorption ratio) were the same after treatment with amoxydrate and clavulanate‐potentiated amoxycillin. Administration of clavulanate‐potentiated amoxycillin and probenecid resulted in elevation and prolongation of serum amoxycillin levels. Computations showed that in preruminant calves serum amoxycillin concentrations sufficient to inhibit sensitive pathogens can be maintained by oral clavulanate‐potentiated amoxycillin treatment at 10 mg/kg TID. At two times that dose rate serum drug concentrations capable of inhibiting 50% of all types of pathogens examined can be maintained. Amoxycillin was apparently inactivated by the g.i. contents of early ruminant (6 weeks old) calves as oral clavulanate‐potentiated amoxycillin treatment at 20 mg/kg did not result in serum drug levels

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00086.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

van Dijk, P., Degryse, A.‐D., Ooms, L.&Lagerweij, E. Clinical, cardiovascular and respiratory effects of R8110 in premedicated dogs.J, vet. Pharmacol. Therap.10, 114–118.The clinical, cardiovascular and respiratory effects after i.v. administration of R8110, a fluoro analogue of etomidate (Fig. 1), were studied in pre‐medicated dogs. The clinical observations were made at doses of 3 and 4 mg/kg body weight (BW) injected slowly i.v., whereas cardiovascular and respiratory studies were carried out at a dose rate of 3 mg/kg R8110 i.v. Induction and recovery were smooth and no significant side‐effects were observed. The cardiovascular system was slightly influenced, but respiration was hardly affected. The effect of pre‐medication on respiration and the cardiovascular system was hardly potentiated by R8110. Although there were significant changes in cardiovascular and biochemical parameters, all values remained within physiological limits. R8110 appeared to be a safe and reliable induct

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00087.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Ali, B.H., Silsby, J.L.&El Halawani, M.E. The effect of magnesium aspartate, xylazine and morphine on the immobilization‐induced increase in the levels of prolactin in turkey plasma.J. vet. Pharmacol. Therap.10, 119–126.The effect of pre‐treating turkey poults (8 weeks old) with magnesium aspartate, xylazine or morphine on the concentration of prolactin (PRL) in plasma was studied in normal birds, and birds stressed with immobilization. Acute immobilization (2 h) without drug treatment increased significantly the PRL concentration in plasma. Pretreatment with magnesium aspartate (405 mg/ml) at intramuscular doses of 100, 200, and 400 mg/bird decreased significantly, in a dose‐dependent manner, the PRL plasma concentration when compared with the immobilized birds. Drug treatment without immobilization had no significant effect on PRL concentration. Similar results were obtained with xylazine (20 mg/ml) when given to birds intramuscularly at doses of 5, 10, or 20 mg/bird, 1 h before immobilization. Morphine, at intramuscular doses of 5 or 10 mg/kg, did not affect significantly the prolactin concentration of immobilized turkeys. At a dose of 25 mg/kg, however, it significantly lowered the PRL plasma concentration in immobilized birds. Morphine treatment alone did not influence significantly the basal PRL plasma concen

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00088.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Mohammed‐AH, N.A.K.&Bogan, J. A. The pharmacodynamics of the flukicidal salicylanilides, rafoxanide, closantel and oxyclosanide. J. vet. Pharmacol. Therap. 10, 127–133.The pharmacokinetics of oxyclosanide, rafoxanide and closantel were investigated in sheep (n = 5). All three drugs were extensively (<99%) bound to plasma proteins and the plasma concentration/time curve was best described by a tri‐exponential equation. Closantel and rafoxanide had long terminal half‐lives (mean 14.5 and 16.6 days, respectively) compared with oxyclosanide (mean 6.4 days). In a study of the efficacy of rafoxanide againstFasciola hepatica, a dose rate of 7.5 mg kg‐1against 6‐week‐old flukes appeared to be similarly effective to a dose rate of 2.5 mg kg‐1against 10‐week‐old flukes (86% and 88% efficacy, respectively), as assessed at autopsies carried out on all sheep when the flukes were 14 weeks old. Part of this putative efficacy against immature flukes may be due to rafoxanide persisting in the plasma and affecting the mature flukes when they r

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00089.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Cullen, L.K.&Reynoldson, J.A. Cardiovascular and respiratory effects of the acaricide amitraz. J. vet. Pharmacol. Therap. 10, 134–143.Amitraz is a formamidine compound used as a topical acaricide mainly in dogs and cattle. In an initial attempt to explain some of its side‐effects, the actions of amitraz were studied on the cardiovascular and respiratory systems in thiopentone/methoxyflurane‐anaesthetized dogs. In separate experiments, amitraz, at doses of 1, 2 and 5 mg/kg i.v., dissolved in DMSO, increased blood pressure for 1 hour. Heart rate decreased initially then showed a dose‐related return towards control values. Tidal volume, respiratory rate and respiratory minute volume all showed initial transient depression. Hyperventilation was a feature after high doses of amitraz. Cumulative doses of amitraz of 0.5, 1, 2, 5 and 10 mg/kg i.v., at intervals of 5 min, increased blood pressure. Heart rate decreased at lower doses but increased slightly after higher doses. Five minutes after injection, cardiac index had returned to control values while total peripheral resistance showed a dose‐related increase. The mechanism of action of amitraz in dogs cannot be determined from these results; however, other reports have described an ci2‐adrenoceptor agonist action of this formamidi

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00090.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Davis, L.E., Neff‐Davis, C.A., Koritz, G.D., Bevill, R.F., Sharma, G.C., Langston, V.C.&Munsiff, I.J. Effect of organic vehicles on the pharmacokinetics of aminophylline administered intravenously to goats.J, vet. Pharmacol. Therap.10, 144–149.Aminophylline dissolved in water, propylene glycol, or dimethyl sulfoxide was administered intravenously to goats in a randomized cross‐over experiment. Model‐dependent and model‐independent pharmacokinetic parameters for theophylline were compared on the basis of the solvent used in the dosage form administered. No difference was found in any pharmacokinetic parameter. Thus, we found no evidence for the possibility that the organic solvents studied would confound pharmacokinetic investigations of theophylline and similar lipophi

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00091.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Dawson, J., Lees, P.&Sedgwick, A.D. Actions of non‐steroidal antiinflammatory drugs on equine leucocyte movement in vitro. J. vet. Pharmacol. Therap. 10, 150–159.The direct effects of four non‐steroidal anti‐inflammatory drugs (NSAIDs) on equine polymorphonuclear (PMN) and mononuclear (MN) leucocyte movement were investigated using twoin vitroassay systems. The Boyden chamber microfilter technique measures both chemokinetic and chemotactic locomotion, and the agarose microdroplet assay measures solely chemokinesis. Zymosan‐activated plasma (ZAP) and the synthetic peptide N‐formyl‐methionyl‐leucyl‐phenylalanine (FMLP) were used as standard chemoattractants for PMN and MN leucocytes, respectively. The actions of six concentrations of each NSAID, indomethacin (50 μM–10 mM), phenylbutazone (10 μM–1 mM), oxyphenbutazone (2.5 μM–500 μM) AND flunixin (0.1 μw–50 μM), in suppressing cell movement induced by ZAP and FMLP were investigated. All four drugs exerted inhibitory effects on induced movement of both cell types in the Boyden chamber assay, usually in a concentration‐dependent manner, although oxyphenbutazone action on PMN cells occurred only at the highest concentration tested. Significant inhibition of PMN and MN cell locomotion was produced by indomethacin, flunixin and oxyphenbutazone, and inhibition of PMN movement by phenylbutazone occurred in the agarose microdroplet assay. Flunixin was the most potent of the four drugs investigated in both assay systems. The findings may be of importance to the use of phenylbutazone and flunixin as NSAIDs in equine medicine, since the concentrations used were similar to concentrations of both drugs and the phenylbutazone metabolite oxyphenbutazone previously reported to occur in equin

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00092.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00093.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00094.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1987.tb00095.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY