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Antihistamines added to an antileukotriene in treating seasonal allergic rhinitis: histamine and leukotriene antagonism.

Cysteinyl leukotrienes (CysLTs) are a key element of allergic inflammation. Thus, the antagonism of CysLTs appears a potential target of allergic rhinitis management. Antileukotrienes and antihistamines combined showed a synergistic effect in treating seasonal allergic rhinitis (SAR). This double blind, parallel group, randomized study aimed at evaluating the clinical and anti-inflammatory effects exerted by two combinations of antihistamine plus antileukotriene in patients with SAR and mild intermittent asthma. Thirty patients were treated with montelukast added to cetirizine (M-C group) or desloratadine (M-D group) for 2 weeks. The visits, including spirometry, nasal scraping and lavage, were performed in all subjects before and directly after the treatment. Evaluation parameters were: i) nasal symptoms, ii) number of eosinophils and neutrophils, and iii) IL5 and IL8 levels. Both combinations significantly reduced: nasal symptoms (p<0.001), eosinophils and neutrophils (p<0.001), IL5 (p<0.001 for M-C groupand p<0.01 for M-D group), and IL8 levels (p<0.001 for M-C group and p<0.05 for M-D group). M-C combination reduced more significantly than M-D combination: nasal symptoms (p<0.01), inflammatory cells (p<0.01), and cytokines (p<0.01). The present study demonstrates that these antileukotriene-antihistamine combinations are effective in relieving nasal symptoms in SAR. Moreover, these combinations exert additional anti-inflammatory activity as provided by reduction of inflammatory infiltrate and cytokine levels. Finally, cetirizine might exert more beneficial activity than desloratadine when added to montelukast.

Acetates↗

Onset of action for the relief of allergic rhinitis symptoms with second-generation antihistamines.

Onset of action for relief of allergic rhinitis symptoms is of clinical significance to both the physician and the patient. Using either subjective or objective methods, the onset of action after a single, oral dose of an antihistamine can be measured. Multicenter studies, outdoor studies, and pollen challenge systems have been used to measure the onset of action. A literature search from 1985 to May 2002 was performed. All published, randomized, placebo-controlled clinical studies pertaining to the onset of action for relief of allergic rhinitis symptoms after a single, oral dose of a second-generation antihistamine (not combined with a decongestant) including cetirizine, desloratadine, fexofenadine, and loratadine, were reviewed. The onset of action for cetirizine ranged from 59 minutes to 2 hours and 6 minutes and for loratadine onset of action ranged from 1 hour and 42 minutes to none identified during the duration of the study. Cetirizine had a shorter onset of action than loratadine for all comparisons. Fexofenadine had an onset of action within 60 minutes. The literature search did not reveal any published onset of action studies for desloratadine. The onset of action for a given second-generation antihistamine depends on how it is defined and subsequently measured.

Cetirizine↗

Comparative efficacy of wheal-and-flare suppression among various non-sedating antihistamines and the pharmacologic insights to their efficacy.

BACKGROUND AND OBJECTIVE: Non-sedating antihistamines (loratadine, fexofenadine, and cetirizine) have been widely used in Thailand. This study examined the time-of-onset and compared the 95% inhibitory effect of these agents on histamine-induced cutaneous reaction so as to understand the diversity of their efficacy. PATIENTS AND METHOD: Thirty-one atopic patients were randomized into 4 treatment groups, placebo (n = 7), loratadine (n = 8), fexofenadine (n = 8), and cetirizine (n = 8). They were pricked with histamine every 30 min for 4 hrs. The percentage change of the wheal/flare area was calculated. RESULTS: All active treatments showed wheal suppression superior to placebo after 210 min for loratadine (P = 0.04); 90 min for fexofenadine (P = 0.009); and 60 min for cetirizine (P = 0.02), while flare suppression was significantly marked after 150 min (P = 0.0008) for loratadine; 90 min for fexofenadine (P = 0.0001), and 60 min for cetirizine (P = 0.006). All drugs except loratadine demonstrated a 95% suppression of wheal superior to the placebo (P = 0.001 for fexofenadine; P = 0.0001 for cetirizine). Only fexofenadine exhibited a 95% suppression of flare statistically superior to placebo (P = 0.02). Discrepancies among the effects of these 3 antihistamines were also detected. DISCUSSION AND CONCLUSION: All antihistamines tested repressed the wheal-and-flare area superbly over the placebo within 4 hours. Cetirizine exerted the fastest onset, and it also appeared to be the most efficacious inhibitor. The heterogeneity of their efficacy probably stems from their diverse physicochemical properties, which have also been discussed.

Adolescent↗

Infusion-related reactions to infliximab in patients with rheumatoid arthritis in a clinical practice setting: relationship to dose, antihistamine pretreatment, and infusion number.

OBJECTIVE: We describe infusion-related reactions to infliximab (during infusion or within 1 hour postinfusion) in patients with active rheumatoid arthritis (RA) treated in a quaternary care center. METHODS: We followed 113 patients for a mean of 60.6 +/- 28.9 weeks, obtaining 10.5 +/- 4.9 infusions per patient. RESULTS: We observed 1183 infusions resulting in 104 infusion reactions (8.8%). All reactions resolved within several hours following cessation of the infusion and none was serious enough to warrant hospitalization. Reactions included allergic reactions (pruritus, urticaria) in 4.2% of infusions, cardiopulmonary (hypotension, hypertension, tachycardia) in 3.0%, and miscellaneous reactions (headache, nausea, vomiting) in 2.0%. Reactions occurred in 8.0% of 3 mg/kg infusions and in 10.3% of 5 mg/kg infusions. Reactions occurred in 13.2% of infusions that involved antihistamine pretreatment compared to only 7.5% of infusions that involved no pretreatment. At both infliximab doses, there was a similar frequency of infusion reactions in patients pretreated due to a previous infusion (12.6%) compared to those pretreated strictly based on infusion number (14.7%). A number of the reactions involving antihistamine pretreatment may be explained by known side effects of diphenhydramine, including headache, dizziness, nausea, and palpitations. CONCLUSION: Infusion-related reactions to infliximab were infrequent, rarely severe, and easily manageable. The frequency of reactions was equivalent in patients treated with 3 mg/kg compared to 5 mg/kg. Reactions were significantly more frequent in infusions where patients were pretreated with the antihistamine diphenhydramine, compared to those not involving pretreatment.

Adolescent↗

[Comparative activity of antihistamines on area under dose-response curve from histamine-induced wheal and flare responses in human skin].

OBJECTIVE: To compare the activity of antihistamines by the index of area under dose-response curve (AUDRC) obtained from histamine-induced wheal and flare reactions. METHODS: Mizolastine 10 mg, loratadine 10 mg, and placebo were given to 90 healthy volunteers and 60 allergic patients in a double-blind and randomized manner. Histamine titration tests (histamine concentrations 54.3, 20.0, 7.3, and 2.7 mmol/L) were performed for each one before dosing and 2, 4, and 24 hours after dosing. The reactivity was evaluated by histamine-induced wheal and flare areas. The AUDRC values of the wheal and flare areas as a function of the natural logarithm transformed histamine concentration were calculated for each subject, and compared. RESULTS: There was no significant difference of the wheal and flare areas between health volunteers and allergic patients. The AUDRC(27-54.3 mmol/l.) for wheal and flare of mizolastine was 115.7, 23.4, 7.7, 49.8 and 902.1, 40.9, 2.6, 46.9 ln (mmol/L) x mm2 at each time (before dosing and 2, 4, 24 hours after dosing) respectively. Compared with loratadine [116.2, 80.2, 49.7, 71.9 and 957.6, 495.3, 153.5, 205.9 ln (mmol/L) x mm2], mizolastine decreased AUDRC(2.7 - 54.3 mmol/L significantly (P < 0.01). CONCLUSION: Histamine-induced wheal and flare inhibition test is a reliable pharmacodynamic model for antihistamines, and AUDRC may be an useful index to predict antihistamines pharmacodynamic activity.

Adolescent↗

Review of H1 antihistamines in the treatment of chronic idiopathic urticaria.

Chronic idiopathic urticaria (CIU) can have a profound effect on patient quality of life (QOL). Ideally, any therapy used to treat CIU should be effective across a wide range of doses without causing unwanted side effects; a wide therapeutic window allows the physician to tailor treatment to the individual. Oral H1 antihistamines are the mainstay of therapy for CIU, but agents within this class diverge in their individual therapeutic indices. The literature was reviewed to compare the currently available oral H1 antihistamines regarding their efficacy and safety at a wide range of doses. If sedation and cognitive impairment are considered relevant to treatment selection due to their effect on QOL and safety, then newer-generation agents should be selected over older-generation antihistamines. There are few well-controlled clinical studies in which newer-generation agents have been directly compared. Moreover, there are no evidence-based data demonstrating statistical superiority of one newer-generation agent over another in the treatment of CIU. However, of the newer agents, those that are labelled nonsedating at recommended doses (fexofenadine, loratadine, and desloratadine) should be selected over cetirizine. In cases where the physician judges that a higher-than-recommended dose should be prescribed, or when the patient is likely to take a higher dose, the relative safety profile of these agents demands detailed consideration.

Anti-Inflammatory Agents↗

[Nonsedative H1 antihistaminics].

Recent research provided evidence that effective H1-antihistaminic drugs need not exert a central and sedative action. Non-sedative H1-antihistaminics can aptly replace older combined preparations of classical H1-antihistaminics, motivated by an effort to weaken their sedative action by the concurrent administration of pharmaceutical preparations with a central stimulating action (e.g. Bromadryl F). The new group of non-sedative histamine H1-antagonists uses in a rational way changes of the physical and chemical properties of these substances or differences in their affinity to histamine H1-receptors in different areas to reduce the incidence of typical undesirable effects.

Animals↗

Objective antihistamine side effects are mitigated by evening dosing of hydroxyzine.

First-generation antihistamines have potency, pharmacokinetic, and cost advantages compared with nonsedating second-generation antihistamines. Bedtime dosing of hydroxyzine was investigated as a dosing strategy to minimize reaction time degradation and adverse subjective symptoms previously documented for hydroxyzine in divided doses. Hydroxyzine, 50 mg qhs, was compared with terfenadine, 60 mg bid, in this double-blind, placebo-controlled crossover study of 15 healthy, asymptomatic adults. Computer-based eye-hand reaction time tests of simple reaction time (SRT) and choice reaction time (CRT) were not statistically different among the three drugs. Drowsiness, dry mouth, and irritability were significant for hydroxyzine (P = .0001, .001 and .02, respectively) compared with terfenadine or placebo, but less than seen in a previous study of hydroxyzine, 25 mg bid. Symptom scores with terfenadine were comparable to placebo. Histamine skin test wheal and flare were both significantly and comparably suppressed by hydroxyzine and terfenadine (P = .0001). While wheal suppression by hydroxyzine was universal, four of the 15 subjects showed little or no suppression with terfenadine (P = .03). Although bedtime dosing of hydroxyzine did not eliminate subjective symptoms, it maintained skin H1-receptor antagonism the following morning and alleviated the prolongation of reaction times previously reported with hydroxyzine in divided doses. The significant adverse subjective symptoms and psychomotor performance degradations caused by first-generation antihistamines can be mitigated by creative dosing schedules.

Administration, Oral↗

Cetirizine: more than an antihistamine?

Cetirizine, a metabolite of hydroxyzine, is an antihistamine with as distinguishing features: 1) exquisite anti-H1 specificity: cetirizine appears unique in being devoid of action on receptors other than the H1 receptor; 2) potency: at unit dose it is the most potent antihistamine in the skin and the lung; 3) absence of metabolism. These three characteristics suggest that cetirizine be considered the choice H1 antagonist for experiments on the immediate allergic reaction. Cetirizine additionally in vitro inhibits the migration of eosinophils, and in vivo, in the skin, the infiltration by eosinophils that is characteristic for the late phase allergic reaction. Other antihistamines are less active or inactive with respect to this property. According to several lines of evidence, the effect of cetirizine on eosinophils is unlikely to be due to H1 antagonism, but is more likely a novel property of the compound.

Allergens↗

[Enhancement of nonsteroidal, anti-inflammatory drugs and preventive effect of antihistamines and disodium cromoglycate on wheat allergy].

BACKGROUND: Aspirin has been known to be an enhancer to wheat allergy, including wheat-dependent, exercise-induced anaphylaxis. OBJECTIVE: To investigate whether nonsteroidal, anti-inflammatory drugs (NSAIDs) other than aspirin would enhance allergic reactions after wheat ingestion and whether antihistamines and disodium cromoglycate would prevent these reactions. METHODS: Seven cases, whose reactions after wheat ingestion were enhanced by aspirin on challenge tests, were enrolled. Skin prick tests (SPT) and CAP-RAST were undergone for wheat and gluten. We used challenge tests of wheat after pretreatment of NSAIDs and preventive drugs. RESULTS: Four cases were diagnosed with wheat allergy, 3 cases had wheat-dependent, salicylic acid-induced anaphylaxis. SPT and CAP-RAST were positive for wheat and gluten in 5 of 7 cases and 4 of 7 cases, respectively. Dicrofenac enhanced the allergic reactions after wheat ingestion in 1 of 2 cases, whereas etodolac failed to enhance the symptoms in all 5 cases performed. Furthermore, disodium cromoglycate could not completely prevent the allergic reaction in all 4 cases and even enhanced the reaction in 1 case of them. To see an inhibitory effect of antihistamines on the symptoms, fexofenadine (in 2, 1 and 1 case, respectively), olopatadine, and chlorpheniramine were administrated before the challenge test, and as a result these drugs were found to have inhibitory effects on the allergic reaction. CONCLUSION: In this study, it was suggested that etodolac might be a relatively safe anti-inflammatory drug on wheat allergy and antihistamines could prevent allergic reactions more than DSCG in patients with wheat allergy.

Adult↗

Quantitative determination of four antihistamines in combination by high-pressure liquid chromatography.

A procedure used to assay four antihistamines--brompheniramine maleate, chlorpheniramine maleate, pheniramine maleate and pyrilamine maleate in combination--is discussed. The method requires a high-pressure liquid chromatograph and an intermediate polarity column. The method is accurate and appears to be stability-indicating. The four antihistamines can be separated and assayed accurately. There is no interference from the two commonly used decongestants, phenylephrine hydrochloride and phenylpropanolamine hydrochloride, from the expectorant potassium guaiacolsulfonate, from the preservative propyl paraben or from two other antihistamines, diphenhydramine hydrochloride and bromdiphenhydramine hydrochloride. Guaifenesin, methylparaben and sodium benzoate interfere only with pheniramine maleate. Methapyrilene hydrochloride interferes only with pyrilamine maleate.

Chromatography, High Pressure Liquid↗

A study on CNS-side effects of mequitazine, an H1-specific antihistamine in healthy Thai volunteers.

Mequitazine is a potent, non-sedative, long-acting H1-specific antihistamine proven to be a better therapeutic drug than other conventional antihistamines. It is also reported by many authors that the drug produces less sedative or other depressive actions on the central nervous system than other antihistamines. In order to evaluate the advantage of this drug in Asian people, an assessment of side effects of mequitazine, in comparison with chlorpheniramine, on the central nervous system was done in 20 healthy Thai volunteers, 10 males and 10 females 23-39 years of age, using a double blind crossover placebo controlled trial. Various subjective tests: alertness scale rating, visual analogue scale rating as well as objective tests: card sorting, glassbead picking and estimation of reaction time, were performed. There were no significant differences in side effects on the central nervous system between mequitazine and the placebo, whereas chlorpheniramine did produce side effects.

Adult↗

Postadulticide pulmonary hypertension of canine heartworm disease: successful treatment with oxygen and failure of antihistamines.

Postadulticide pulmonary hypertension mechanisms and treatment with antihistamines and supplemental oxygen were studied in eight dogs with heartworm disease. To ensure severe postadulticide thromboembolism, additional heartworms (either 20 or 40 into 4 dogs each) were transplanted into naturally infected dogs before thiacetarsamide treatment. During pentobarbital anesthesia, 2 pulmonary hemodynamic studies were conducted on each dog with a sequence of baseline, hypoxia with FlO2 = 10%, hyperoxia with FlO2 = 100%, a second baseline, treatment with either diphenhydramine (D) or cimetidine (C), and another hypoxia. All dogs were pulmonary hypertensive, with each dog having a mean pulmonary arterial pressure (PPA) greater than 20 mm of Hg. Mean PPA increased from baseline conditions (25.0 +/- 4.5 SD for D and 24.3 +/- 4.4 for C) to hypoxia (28.5 +/- 4.7 for D and 28.4 +/- 3.7 for C), and decreased during hyperoxia (16.9 +/- 3.0 for D and 17.4 +/- 3.0 for C), respectively. Neither antihistamine reduced PPA at normoxia. The degree of pulmonary hypertension when breathing room air increased even more during hypoxia, and this increase was not attenuated by either antihistamine. Histamine did not appear to mediate pulmonary hypertension during postadulticide thromboembolism, nor to modify the hypoxia-mediated pulmonary hypertension at this disease stage. Because baseline PO2 was low (66.6 +/- 11.7 mm of Hg for D and 69.4 +/- 14.2 for C) and because PPA decreased during administration of oxygen, the pulmonary hypertension was mostly hypoxia-induced. In addition to the arterial lesions, much of the pulmonary hypertensive mechanism was an active and reversible vasoconstriction in response to hypoxia caused by the secondary lung disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Histamine in the rat brain: effect of acute and chronic treatment with tricyclic antidepressants and H1-antihistaminics.

Prolonged (for two weeks), but not acute, intensive treatment with tricyclic antidepressant drugs (amitriptyline, AMI; doxepine, DOX; imipramine, IMI) and H1-antihistaminics (chloropyramine, CPYR; diphenhydramine, DPHA; promethazine, PMZ; tripelenamine, TPA) decreased histamine (HI) level in rat brain, especially in the cerebral cortex. These drugs did not modify L-histidine decarboxylase activity in any analyzed brain structure, except chronically given AMI and IMI which significantly increased the enzyme activity. None of the tested compounds, administered both acutely or chronically, affected the activity of HI-methyltransferase, as well as HI level in the heart. Under in vitro conditions, all antidepressants, PMZ and CPYR, but not DPHA or TPA, only at high concentrations (10(-3) or 3 X 10(-3M) released HI from both pleural and PMZ did not modulate the pleural mast cells HI-releasing profile of both DOX or DPHA. Chronic treatment with the antidepressants and the H1-antihistaminics decreased slightly but not significantly HI contents in the brains of L-histidine-treated rats. It is suggested that the decrease in the brain HI levels induced by chronic administration of both tricyclic antidepressants and H1-antihistaminics is, most probably, a consequence of HI release from central histaminergic nerve terminals; this release could result from the drug-produced persistent blockade of central H1- and/or H3- (i.e. HI auto-receptors)receptors.

Animals↗

The effects of H1 antihistamines on the early allergic response.

To increase understanding of the effect of H1 antihistamines on the immediate response to nasal challenge with antigen, we performed two double blind, placebo-controlled, crossover studies using cetirizine and terfenadine. The subjects underwent nasal challenge with antigen after premedication with either cetirizine (20 mg QD for two days, n = 10), terfenadine (60 mg BID for 1 week, n = 12), or placebo for equivalent periods of time. We monitored the response to challenge by counting the number of sneezes and by measuring the levels of inflammatory substances in recovered nasal lavages. Compared with placebo, both antihistamines significantly reduced sneezing and the levels of recovered albumin and TAME esterase activity, suggesting that both reduced the expected increase in vascular permeability. With cetirizine, there was also a reduction in the levels of LTC4 (not measured in terfenadine studies) but not in those of recovered histamine and prostaglandin D2. These data suggest that cetirizine did not affect mast cell mediator release, that histamine release is due to the direct action of antigen stimulation and that leukotrienes are generated by cells in addition to mast cells. With terfenadine, there were significant reductions in the levels of histamine and kinins (not measured in cetirizine study) seen after nasal challenge with antigen. The reduction in kinins most likely reflects alteration in vascular permeability, whereas the effect on histamine presumably reflects inhibition of mast cell activation. When combined, these experiments demonstrate effects of H1 antihistamines on histamine release beyond those usually described, as well as differences between drugs within a single classification.

Benzhydryl Compounds↗

A primate model for the evaluation of antihistamines.

Studies of the efficacy of antihistamines in treating human upper airway pathology are difficult to design and conduct. In part, this is the result of a lack of objective measures of the nasal response. The purpose of this study was to develop a monkey model for the objective evaluation of antihistamine effectiveness and, using this model, to study the efficacy of cetirizine. Computer-assisted active anterior rhinomanometry was used to assess nasal airway resistance (NAR) before and after a nasal histamine provocation in conscious rhesus monkeys (Macaca mulatta). To establish dose-response relationships for oral antihistamines in monkeys, we measured the suppression of wheal-and-flare reactions by two such agents, oral cetirizine (CET) 0.1 to 1 mg/kg and chlorpheniramine (CHL) 0.07 to 0.2 mg/kg. The decreases in wheal sizes were maximal 60 to 120 minutes after CET 1.0 mg/kg (90%), and after CHL 0.2 mg/kg (70%). The four monkeys were challenged intranasally with increasing histamine doses (0.5, 1, 5, and 10 mg). The NAR was measured 15 minutes after each dose. At least three days later and 90 minutes after oral pretreatment with either CET 1 mg/kg or CHL 0.2 mg/kg, the intranasal challenges were repeated. Postchallenge NAR data are given as the percent increase from the baseline NAR values. The four monkeys studied had coefficients of variation of 13%, 15%, 16%, and 26% respectively for baseline studies. Mean percent increases in NAR +/- standard deviation were 14% +/- 0.4%, 47% +/- 10.0%, 45% +/- 3.0%, and 72% +/- 6.0% after intranasal challenge with 0.5, 1, 5, and 10 mg of histamine, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

The use of antihistamines for the treatment of airway disease.

This report reviews studies of the use of antihistamines for the treatment of allergic respiratory diseases. The cumulative results indicate that the nonsedative antihistamine terfenadine, given orally at a dosage of 60 mg twice daily, is effective in the treatment of seasonal allergic rhinitis in both adults and children. No major side effects have been reported, and sensitivity to this agent is not decreased after eight weeks of treatment. Preliminary data on the use of antihistamines for the treatment of asthma are also reviewed.

Astemizole↗

[Antihistaminic and antiserotonin properties of new complex tropine esters].

The antihistaminic and antiserotonin properties of 16 new tropine esters, analogues of atropine, tropacin and tropaphen, were studied. All of them were found to lessen the spasmogenic effects of histamine and serotonin. The intensity of the antihistaminic and antiserotonin action of the drugs varied depending upon the structure of the radical at the alpha-carbon atom in the acidic part of the molecule. Both types of the activity are most marked in the desoxymethyl propyl and butyl analogues of atropine. The absence of the oxymethyl group at alpha-carbon in the series of atropine analogues is shown to facilitate the manifestation of the antihistaminic activity.

Animals↗