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Management of essential thrombocythemia (ET) in high-risk patients is difficult because high platelet numbers can lead to vascular occlusive events and bleeding. Therapeutic interventions in ET are limited to hydroxyurea and anagrelide; however, in Europe, anagrelide is contraindicated in patients with chronic renal disease.
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The present experiments were designed to study the effects of levocetirizine (a potent selective histamine H(1) antagonist) on the contraction induced by histamine on isolated rabbit bronchioles using the precision-cut lung slice technology. Histamine induced a concentration-dependent contraction of isolated rabbit bronchioles (pD(2) value of 5.6). Mepyramine (0.01-1 micromol/l) induced a shift to the right without any decrease in the concentration-response curve to histamine (pA(2) value of 8.2). Levocetirizine (0.03-0.1 micromol/l) induced both a shift to the right and a decrease in the maximal amplitude of the concentration-response curve to histamine (pA(2) and pD'(2) values of 7.9 and 7.0, respectively). The difference between both compounds could be explained in terms of the difference in the dissociation rate from the histamine H(1) receptor coupled to a putative low receptor reserve present in the rabbit bronchioles.
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A prospective medicine usage evaluation based on prescription monitoring was conducted in the medicine OPD of our university teaching hospital to know prescribing trends of different categories of medicines.
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Sensitive enantioselective liquid chromatographic assays using tandem mass spectrometric detection were developed and validated for the determination of S-cetirizine (S-CZE) and R-cetirizine (R-CZE) in guinea pig plasma, brain tissue, and microdialysis samples. Enantioselective separation was achieved on an alpha1-acid glycoprotein column within 14 min for all methods. A cetirizine analog, ucb 20028, was used as internal standard. Cetirizine and the internal standard were detected by multiple reaction monitoring using transitions m/z 389.1 --> 200.9 and 396.1 --> 276.1, respectively. The samples were prepared using protein precipitation with acetonitrile. For guinea pig plasma, the assay was linear over the range 0.25-5000 ng/mL for both S-CZE and R-CZE, with a lower limit of quantification (LLOQ) of 0.25 ng/mL. For the brain tissue and microdialysis samples, the assays were linear over the range 2.5-250 ng/g and 0.25-50 ng/mL, respectively, and the LLOQ values were 2.5 ng/g and 0.25 ng/mL, respectively. The intra- and inter-day precision values were < or =7.1% and < or =12.6%, respectively, and the intra- and inter-day accuracy varied by less than +/-8.0% and +/-6.0% of the nominal value, respectively, for both enantiomers in all the matrices investigated.
Unsupervised learning: principal component analysis (PCA) and supervised learning: consensus orthogonal partial least squares discriminant analysis (OPLS-DA) were utilized to reveal the essential character of Cetirizine impurity profile; 16 differential impurities were finally found, their structures were speculated by HRMS(2) data.
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Summary Background There are no data directly comparing the relative efficacy of modern H(1)-antihistamines in allergic rhinitis using nasal provocation challenge. Objective We elected to study the comparative effectiveness of usual clinically recommended doses of desloratadine (DES), fexofenadine (FEX), and levocetirizine (LEV), on nasal adenosine monophosphate (AMP) challenge in patients with perennial allergic rhinitis (PAR). Methods 16 patients with PAR were randomized in double-blind cross-over fashion to receive single doses of DES 5 mg, FEX 180 mg, LEV 5 mg, or placebo (PL), with nasal AMP challenge performed 12 h after dosing. Measurements of peak nasal inspiratory flow (PNIF) were made over 60 min after nasal AMP challenge. Results Pre-challenge values (mean+/-SEM) for PNIF (L/min) were not significantly different comparing all groups; DES (129+/-9), FEX (128+/-11), LEV (128+/-13), and PL (128+/-12). The maximum % PNIF fall from baseline over 60 min after nasal AMP challenge was significantly attenuated (P<0.05) compared to PL (50+/-4), with DES (32+/-5), FEX (36+/-4), and LEV (36+/-4). The area under the 60-min time-response curve (%.min) was also significantly attenuated (P<0.05) compared to PL (2110+/-268), with DES (1126+/-285), FEX (1225+/-255), and LEV (1261+/-194). There were no significant differences between the three H(1)-antihistamines for any outcomes. Conclusion DES, FEX, and LEV were equally effective in attenuating the response to nasal AMP challenge. However, further long-term studies will be required to study their comparative effects on nasal symptoms, quality of life, as well as on nasal inflammatory cells.
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According to recent literature, the "anti-allergy" properties of antihistamines are linked to their antagonistic ability on receptor H1. In the majority of experimental models the immediate allergic responses is followed by a late phase. Especially at the pulmonary level, the presence of a late response after an allergic provocation is considered to correlate with the severity of asthma. The reference anti-allergy drugs, such as the inhaled corticosteroids or the cromones, without anti H1 activity, inhibit this late pulmonary response. Azelastine, ketotifen and cetirizine, three substances that are antagonistic to the anti-H1 receptor reduce the late pulmonary response. In addition, these three substances have other "anti-allergy" characteristics. Azelastine inhibits production of superoxide by the pulmonary neutrophils and eosinophils after PAF provocation in animals. Cetirizine significantly inhibits eosinophil infiltration in the bronchoalveolar lavage liquid in asthmatics with a late allergic bronchospasm. The presence of anti-histaminic and anti-allergy characteristics on the same molecule may perhaps convey a supplementary therapeutic benefit in the treatment of allergic symptoms.
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The initiation of the antihistamine effect of a single dose of acrivastine (8 mg) or cetirizine (10 mg) on wheals and itch induced by histamine dihydrochloride (10 mg/ml) in the prick test was studied in a randomized cross-over design employing 20 healthy medical students. The prick test was performed before ingestion of the drug and after 15, 20, 25, 30, 60 and 90 min and 2, 3 and 4 h. Local symptoms (itching) were recorded on a visual analogue scale. The inhibitory effect of acrivastine on the histamine wheal was first noticed 20 min (p < 0.01) after ingestion of the drug and that of cetirizine after 60 min (p < 0.001). The maximum effect of cetirizine, at 4 h, was greater than that of acrivastine, at 3 h (p < 0.001). The suppression of itching was first noticed 25 min after ingestion with both drugs.
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Following a single 10-mg oral dose of cetirizine dihydrochloride to 24 healthy volunteers, the analyte was quantified in human plasma. Protein precipitation using acetonitrile (ACN) was followed by reversed-phase liquid chromatography and tandem mass spectrometry. The MS/MS method was optimised using a PE Sciex API 2000 triple quadrupole mass spectrometer in selected reaction monitoring (SRM) mode, using electrospray with positive ionisation. Oxybutynin was used as the internal standard. The assay method represents a robust, high-throughput, highly specific and sensitive quantitative assay procedure, with 0.5 ng/ml being the lowest plasma concentration that could be reliably quantified. The procedure involves minimal sample preparation, and is well suited to clinical studies of the drug involving large numbers of generated samples. Pre-dose as well as post-dose samples up to and including 48 h were quantified, and the data generated were used to determine the pharmacokinetic profile of the drug.
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Bradykinin, 10 to 1000 micrograms given by aerosol into the nasal cavity of normal, healthy volunteers, produced a dose-related increase of nasal airway resistance. Bradykinin also reduced the minimal nasal cross-sectional area (Amin), increased albumin release into nasal lavage fluid and increased the symptoms of nasal inflammation. Pretreatment with cetirizine (10 mg orally) reduced the fall in Amin induced by bradykinin, 300 micrograms, but not by bradykinin, 100 micrograms. Pre-treatment of the subjects with the H1 histamine receptor antgonist cetirizine (10 mg, orally) or terfenadine (60 mg, orally) 3 h before bradykinin administration caused significant reduction of the bradykinin-induced increase in nasal airway resistance in the upper range of bradykinin doses (300-1000 micrograms) but not in the lower range (10-100 micrograms). Cetirizine reduced the albumin release into the nasal airway and the symptoms induced by bradykinin, 1000 micrograms. Following nasal challenge with bradykinin 300 micrograms or 1000 micrograms, no increase could be detected in the histamine content of nasal lavage fluid. Isolated human nasal cells released histamine in response to bradykinin, 33 and 100 microM, anti-IgE and calcium ionophore, A23187. We conclude that the actions of bradykinin in the human nasal airway are, in part, accounted for by the release of histamine.
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H(1)-antihistamines are first line treatment of chronic urticaria, but many patients do not get satisfactory relief with recommended doses. European guidelines recommend increased antihistamine doses of up to 4-fold.
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Allergic rhinitis affects 20 million of people in United States and a higher figure all around the world.
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The warm acupuncture in both summer and winter achieves the definite efficacy on AR and the effect mechanism is relevant with reducing serum IgE level.
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The synthesis and potential H1 receptor antagonistic activity of two novel series of condensed 2-arylaminoethylpyrimidin-4(3H)-ones (4, 5) and 4-amino-2-arylaminoethyl pyrimidines (6) have been reported. All the novel compounds were found to antagonize histamine in a competitive and reversible manner. When tested on guinea-pig ileum, compounds exhibited H1-antagonistic activity, (pA2 values) in the range of 8.6 to 9.7. Some of the lead compounds were evaluated by an in vivo method and were found to protect the guinea pigs against the histamine induced asphyxic shock at the doses comparable to or lower than those of the standard drugs, cetirizine (CAS 83881-51-0) and terfenadine (CAS 50679-08-8). The pA2 acetylcholine values of some of the lead compounds reflect about 1000-fold selectivity for histamine (H1) receptors. The 4-aminopyrimidines (6) were found to be more selective than their 4-one analogs (4, 5). In the radioligand binding study, one of the lead compounds, 6e, was found to bind reversibly at the histamine H1 receptor with the K1 value of 1.3 mumol/l and IC50 of 3.8 mumol/l. The lead compounds were found to have negligible sedative potential when tested in vivo. An indirect type of molecular modeling approach, using temelastine (CAS 86181-42-2) as the standard ligand, indicates that the potent activity of 4, 5 and 6 may be due to the increased spacer chain length between the pyrimidine nucleus and the side-chain aromatic ring.
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There is some evidence suggesting that factors other than autoantibodies to FceRI or IgE and histamine released from mast cells may play a role in skin autoreactivity that characterizes many patients with chronic urticaria (CU) and, possibly, in the pathogenesis of this disease.
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A dissolution test for a once daily combination tablet containing 10 mg of cetirizine dihydrochloride (cetirizine HCl) for immediate release and 240 mg of pseudoephedrine hydrochloride (pseudoephedrine HCl) for extended release was developed and validated according to current ICH and FDA guidelines. The cetirizine HCl is contained within an outer layer of the tablet while a semipermeable membrane of cellulose acetate and polyethylene glycol controls the rate at which pseudoephedrine HCl is released from the tablet core. The dissolution method, which uses USP apparatus 2 with paddles rotating at 50 rpm, 1000 ml of deaerated water as the dissolution medium, and reversed-phased HPLC for quantitation, was demonstrated to be robust, discriminating, and transferable. These test conditions were selected after it was demonstrated that the cetirizine HCl portion of the tablet rapidly dissolved in aqueous media over the physiologically relevant pH range of 1.1-7.5, and that the extended-release profile of pseudoephedrine HCl was independent of dissolution conditions (i.e., apparatus, pH, and agitation).
The aim of the following study was to characterize a passive systemic anaphylaxis rat model of dinitrophenyl (DNP)-induced plasma extravasation in the trachea to determine if the model is appropriate for the evaluation of new drugs targeting airway mast cells by oral and intratracheal (i.t.) route. To this purpose we have used fluticasone and a range of anti-allergic drugs including compounds either active on mast cell activation, such as cromoglycate and the Syk inhibitor R406, or active on mast cell mediators, such as cetirizine and montelukast. To further characterize the model, the effect of fluticasone, cromoglycate and R406 on rat tracheal mast cell degranulation was also assessed histologically. DNP-induced tracheal plasma extravasation was inhibited by cromoglycate (i.v. and i.t.) and R406 (p.o.), but not by fluticasone (i.t.), cetirizine or montelukast (p.o.). Cromoglycate and R406 also showed inhibition of tracheal mast cell degranulation, whereas fluticasone was inactive. These results suggest that the DNP-induced tracheal plasma extravasation model constitutes a useful animal model for the evaluation, by oral and i.t. route, of new anti-allergic drugs intended to target airway mast cells.
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A total of 240 male Swiss mice, 10 weeks of age were synchronized for 3 weeks by 12 h light (rest span)/12 h dark (activity span). Different doses of cetirizine were administered orally at fixed times during the day to determine both the sublethal (TD(50)) and lethal (LD(50)) doses, which were, respectively, 55 +/- 0.35 and 750 +/- 0.40 mg/kg. In the chronotoxicologic study a single dose of cetirizine (DL(50)) was administered to comparable groups of animals at six different circadian stages [1, 5, 9, 13, 17, 21 h after light onset (HALO)].
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The efficiency of wastewater ozonation for the abatement of three nitrogen-containing pharmaceuticals, two antihistamine drugs, cetirizine (CTR) and fexofenadine (FXF), and the diuretic drug, hydrochlorothiazide (HCTZ), was investigated. Species-specific second-order rate constants for the reactions of the molecular, protonated (CTR, FXF) or deprotonated (HCTZ) forms of these compounds with ozone were determined. All three compounds are very reactive with ozone (apparent second order rate constants at pH 7: kO3,pH7 = 1.7·10(5) M(-1)s(-1), 8.5·10(4) M(-1)s(-1) and 9.0·10(3) M(-1)s(-1) for CTR, HCTZ and FXF, respectively). Transformation product (TP) structures were elucidated using liquid chromatography coupled with high-resolution tandem mass spectrometry, including isotope-labeled standards. For cetirizine and hydrochlorothiazide 8 TPs each and for fexofenadine 7 TPs were identified. The main TPs of cetirizine and fexofenadine are their respective N-oxides, whereas chlorothiazide forms to almost 100% from hydrochlorothiazide. In the bacteria bioluminescence assay the toxicity was slightly increased only during the ozonation of cetirizine at very high cetirizine concentrations. The main TPs detected in bench-scale experiments were also detected in full-scale ozonation of a municipal wastewater, for >90% elimination of the parent compounds.
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Although all kinds of medications should be avoided during pregnancy, the majority of pregnant women receive at least one drug and 6% of them during the high-risk period of the first trimester. The aim of the present paper is to discuss the appropriate management of rhinologic and laryngeal conditions that may be encountered during pregnancy. A literature review from Medline and database sources was carried out. Related books and written guidelines were also included. Controlled clinical trials, prospective and retrospective studies, case-control studies, laboratory studies, clinical and systematic reviews, metanalyses, and case reports were analysed. The following drugs are considered relatively safe: beta-lactam antibiotics (with dose adjustment), macrolides (although the use of erythromycin and clarithromycin carries a certain risk), clindamycin, metronidazole (better avoided in the first trimester), amphotericin-B (especially in immunocompromised situations during the second and third trimester) and acyclovir. First-line antituberculous agents isoniazid, ethambutol, pyrazinamide, and ciprofloxacine in drug-resistant tuberculosis can be also used. Non-selective NSAIDs (until the 32nd week), nasal decongestants (with caution and up to 7 days), intranasal corticosteroids, with budesonide as the treatment of choice, second generation antihistamines (cetirizine in the third trimester, or loratadine in the second and third trimester), H2 receptor antagonists (except nizatidine) and proton pump inhibitors (except omeprazole) can be used to relieve patients from the related symptoms. In cases of emergencies, epinephrine, prednisone, prednisolone, methylprednisolone, dimetindene and nebulised b(2) agonists can be used with extreme caution. By contrast, selective COX-2 inhibitors and BCG vaccination are contraindicated in pregnancy. When prescribing to a pregnant woman, the safety of the materno-foetal unit is considered paramount. Although medications are potentially hazardous, misconceptions and suboptimal treatment of the mother might be more harmful to the unborn child. Knowledge update is necessary to avoid unjustified hesitations and provide appropriate counselling and treatment for pregnant women.
A primary culture of human nasal epithelial cells (HNECs) was generated from nasal polyps. After stimulation of epithelial cells with LTA, double-stranded RNA (dsRNA), and LPS, reverse transcription-polymerase chain reaction (RT-PCR) was performed at 1, 6, and 24 h to clarify the optimal stimulation of ICAM-1 in HNECs. To investigate the anti-inflammatory effects of LCEZ, HNECs were pretreated with three different concentrations of LCEZ (500, 50, and 5 nM) for 2 h. HNECs were washed and then stimulated with dsRNA. At 1, 6, and 24 h after stimulation, the level of ICAM-1 was measured by RT-PCR and ELISA. Western blots for TRIF and RIP were performed.
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The histaminergic neurotransmitter system is currently under investigation as a target for drug treatment of cognitive deficits in clinical disorders. The therapeutic potential of new drugs may initially be screened using a model of histaminergic dysfunction, for example, as associated with the use of centrally active antihistamines. Of the selective second generation antihistamines, cetirizine has been found to have central nervous system effects. The aim of the present study was to determine whether cetirizine can be used as a tool to model cognitive deficits associated with histaminergic hypofunction.
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Acupuncture plus rescue medication (RM) (cetirizine) (n = 212), sham acupuncture plus RM (n = 102), or RM alone (n = 108). Twelve treatments were provided over 8 weeks in the first year.
Population analysis predicts a linear increase in cetirizine CL/F and V/F with age, with CL/F being slightly lower in female children, relative to males of the same age. However, this gender difference probably has no clinical consequences. Since V/F increased more rapidly with age than CL/F, a nonlinear increase in half-life was seen, from < 4 h in infants to near the adult value at 12 years of age. The current recommended dosing regimens that younger children should receive lower but more frequent doses, are confirmed by the present analysis.
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A total of 360 patients with perennial allergic rhinitis were randomized in a placebo-controlled, dose-finding study comparing three concentrations (0.06%, 0.125%, and 0.25%) of a cetirizine nasal spray, administered three times a day for 2 weeks. The primary criterion of efficacy was the percentage of days with no or only mild symptoms of rhinitis (PDMax1), as evaluated by the patients. The median PDMax1 were 16.7%, 30.8%, 42.9%, and 26.7% for the placebo, 0.06%, 0.125%, and 0.25% groups, respectively. Although the global comparison among the four groups only approached statistical significance (P = 0.076), the difference (26.2%) between the placebo and 0.125% groups was clinically and statistically significant (P = 0.011). For the global evaluation by the investigator, the best results were seen in the 0.125% group (P = 0.03). The occurrence of adverse events did not differ among the four treatment groups and consisted mainly of nasal events, occurring in 22.5%, 17.1%, 12.9%, and 24.4% of the patients for the placebo, 0.06%, 0.125%, and 0.25% groups, respectively (P = 0.184). These results indicate that the 0.125% concentration is significantly better than placebo and offers the best therapeutic ratio.
Following the end of the treatment, the effect of the antihistamines on skin reaction was subsiding in such an order: after 24 hours in case of loratadine and desloratadine, after two days for both doses of fexofenadine, and 3-4 days for cetirizine and levocetirizine.
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Eight children (3.84 +/- 1.17 years old) received a single oral 5 mg cetirizine dose (0.32 +/- 0.07 mg.kg-1) as a 10 mg.ml-1 solution, 1.73 (+/- 0.64) hours before a minor surgical intervention (mean duration +/- SD = 0.90 +/- 0.25 h). Seven venous blood samples were collected before administration (t0) and 0.5 h, 1.5 h, 4 h, 8 h, 12 h and 24 h after dosing, and urine samples were collected up to 24 hours after the dose. The mean +/- SD kinetic parameters were: peak plasma level (Cmax) 607 +/- 231 micrograms.l-1 reached in 1.93 +/- 1.39 h (tmax), elimination half-life (t1/2) 5.55 +/- 0.98 h, area under the plasma concentration time curve (AUC0-infinity) 4,772.1 +/- 1,318.4 micrograms.l-1.h, mean residence time (MRT) 8.13 +/- 1.31 h, apparent plasma clearance (Cl/f) 1.27 +/- 0.80 ml.min-1.kg-1, apparent volume of distribution (Vz/f) 0.60 +/- 0.38 l.kg-1. Urinary recovery was 38.4 +/- 9.9% (n = 4) of the dose. Renal clearance was 0.42 +/- 0.10 ml.min-1.kg-1 (n = 6). No influence of age on the cetirizine parameters was evidenced among this group, except for MRT (p < 0.05) which decreases with age. When compared with results in adults, elimination half-life (t1/2) was twice as short and apparent clearance twice as great. These results suggest that a higher dosage b.i.d. may be required in children.