Search results for "H1 antagonist"

Models with clinically-relevant and life-threatening histamine-related cardiovascular disturbances: Evaluation of the clinical effectiveness of H1/H2…

1996

Pharmacological characterisation of a new model of antigen-induced pulmonary late-phase reaction in the conscious guinea pig which uses additional po…

1996

The aim of the present study was to develop a new model of allergic late-phase reaction in the airways of conscious guinea pigs (GPs) and to characterise it by pharmacological intervention. GPs were pretreated with cyclophosphamide and sensitized with ovalbumin (OA) in Al(OH)3. Weekly inhalations of polymyxin B were performed before and during sensitization and continued throughout the study period. Under cover of 10 mg/kg i.p. mepyramine all GPs still exhibited a pronounced immediate reaction (IR), peaking during the first 15 min after OA. Nine out of 15 GPs demonstrated, during screening, a reproducible (twice) second phase (late phase reaction (LPR)] of decreased airflow and tidal volume…

Involvement of prostaglandins and 5-hydroxytryptamine in the contractile effect of platelet-activating factor in rat isolated gastric corpus

1996

Abstract The present study characterizes the nature of the response to the platelet-activating factor (PAF) in isolated gastric corpus with and without mucosa. PAF (10-8 M) induced contraction of rat isolated gastric corpus strips followed by desensitization of this tissue. Incubation of strips with the specific PAF-receptor antagonist WEB 2086 (5 × 10-8 − 5 × 10-5 M), the prostaglandin blocker indomethacin (10-6 M) and the 5-hydroxytryptamine antagonist methysergide (10-5 M) reduced significantly the contraction induced by PAF. Neither of the histamine H1/H2 antagonists diphenhydramine (10-6 M) or cimetidine (10-5 M) affected the contraction induced by PAF. In contrast with the whole gastr…

Clinic modelling randomised trials (CMRT's) in animals as a new intermediate between biological experiments and randomised clinical trials: applicati…

1998

Histamine release in mesenteric traction syndrome during abdominal aortic aneurysm surgery: prophylaxis with H1 and H2 antihistamines

2002

Objective and design: Mesenteric traction syndrome is described as sudden tachycardia, hypotension and flush. Among other etiological factors eventeration or mesenteric traction of the small intestine may cause histamine release from mesenteric mast cells. We hypothesized that mesenteric traction syndrome may be positively influenced by prophylactic antihistamine administration.¶Methods: Male patients (n = 17, ASA groups III-IV, 48–78 years old) were investigated in a randomised double blind study during elective abdominal aortic aneurysm (AAA) repair. Eight patients had pre-anaesthetic prophylaxis with dimetindene (H1-receptor antagonist) plus cimetidine (H2-receptor antagonist), 9 patient…

Quantitation of antihistamines in pharmaceutical preparations by liquid chromatography with a micellar mobile phase of sodium dodecyl sulfate and pen…

2002

Abstract A reversed-phase liquid chromatographic procedure with a micellar mobile phase of sodium dodecyl sulfate (SDS), containing a small amount of pentanol, was developed for the control of 7 antihistamines of diverse action in pharmaceutical preparations (tablets, capsules, powders, solutions, and syrups): azatadine, carbinoxamine, cyclizine, cyproheptadine, diphenhydramine, doxylamine, and tripelennamine. The retention times of the drugs were <9 min with a mobile phase of 0.15M SDS–6% (v/v) pentanol. The recoveries with respect to the declared compositions were in the range of 93–110%, and the intra- and interday repeatabilities and interday reproducibility were <1.2%. Th…

Enantiomeric quality control of antihistamines in pharmaceuticals by affinity electrokinetic chromatography with human serum albumin as chiral select…

2007

The present paper deals with the enantiomeric separation of six antihistaminic enantiomers by affinity electrokinetic chromatography (AEKC)-partial filling technique using human serum albumin (HSA) as chiral selector. A multivariate optimization approach of the most critical experimental variables in enantioresolution, running pH, HSA concentration and HSA plug length (SPL) was carried out since there are interactions between variables that could not be considered in an univariate optimization. The estimated and experimental resolution values obtained for antihistaminic enantiomers varied from 1.13 (for orphenadrine) to 2.15 (for brompheniramine). The optimum experimental conditions for ena…

Use of molecular topology for the prediction of physico-chemical, pharmacokinetic and toxicological properties of a group of antihistaminic drugs

2002

We used molecular connectivity to search mathematical models for predicting physico-chemical (e.g. the partition coefficient, P), pharmacokinetic (e.g. the time of maximum plasma level, and toxicological properties (lethal dose, LD) for a group of antihistaminic drugs. The results obtained clearly reveal the high efficiency of molecular topology for the prediction of these properties. Randomization and cross-validation by use of leave-one-out tests were also performed in order to assess the stability and the prediction ability of the connectivity functions selected.

Model building strategies for risk analysis of perioperative histamine-related cardiorespiratory disturbances.

1995

Development of predictive retention-activity relationship models of tricyclic antidepressants by micellar liquid chromatography.

1999

The distribution of tricyclic antidepressants from plasma to brain, where these drugs exert their main clinical action, and other organs is related to transport events across the cell membranes of the different tissues. It could be expected that all the molecular features that condition the transport processes (mainly hydrophobicity and molar total charge) also control the pharmacokinetic and biochemical behavior. Micellar liquid chromatography (MLC) has been proposed to emulate in vitro the partitioning process in the biomembranes. The use of micellar solutions of Brij35 as mobile phases in reversed-phase liquid chromatography has proven to be valid to predict the biological activities of …