Efficacy and safety of mizolastine 10 mg in a placebo-controlled comparison with loratadine in chronic idiopathic urticaria: results of the MILOR study

Effect and safety of probiotics for treating urticaria: A systematic review and meta-analysis

BACKGROUND

To assess the effect and safety of probiotics for treating urticaria.

METHODS

Randomized controlled trial (RCT) papers on the probiotics treatment published before May 2019 were retrieved from various databases like PubMed, EMbase, MEDLINE (Ovid), SCI-Hub, Springer, ClinicalKey, VIP, and CNKI. The treatment plan that we include are oral administration of single probiotic, multiple probiotics, and the combination of probiotics and antihistamines. Meta-analysis of the data was performed by RevMan 5.3 software.

RESULTS

A total of nine RCT papers were included: four papers for oral administration of single probiotic, three papers for oral administration of multiple probiotics, and two papers for oral administration of a probiotic combined with antihistamines. The results of meta-analysis showed that the therapeutic effect of the probiotic group was significantly higher than the control group (placebo or antihistamines) (RR = 1.09, 95% CI: 1.03-1.16, p = 0.006). And compared with the placebo group, the therapeutic effect of single probiotic group was significantly improved (RR = 1.11, 95% CI: 1.01-1.21, p = 0.03). Regarding therapeutic effect, there was no statistically significant difference between the multiple probiotics group and placebo group (RR = 1.00, 95% CI: 0.94 ~ 1.07, p = 0.91); the therapeutic effect of single probiotic combined antihistamine group was significantly higher than the antihistamine group (RR = 1.13, 95% CI: 1.07-1.19, p < 0.0001). Regarding the incidence of adverse reactions, there was no significant difference between the probiotic group and the control group (p = 0.46).

CONCLUSION

The treatment plan of oral administration of probiotics has significant therapeutic effects on urticaria, but the therapeutic effects of the administration of multiple probiotics and the safety of probiotic therapy are still not yet obvious. Some large-scale, multi-centered RCT studies are needed in the future for clarification.

Comparative Safety Profiles of Individual Second-Generation H1-Antihistamines for the Treatment of Chronic Urticaria: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The comparative safety and/or dosing regimens of individual second-generation H1-antihistamines (sgAHs) in patients with chronic urticaria (CU) remain poorly elucidated.

OBJECTIVE

To compare the safety profiles of individual sgAHs and/or dosing regimens in adolescents or adult patients with CU using a systematic review and network meta-analysis of all available evidence.

METHODS

With limited English publications, electronic databases and gray literature were searched for randomized clinical trials from inception, with searches last updated on January 20, 2023. Relevant safety outcomes included treatment unacceptability (all-cause discontinuation), tolerability (discontinuation due to any adverse events), adverse events, serious adverse events, central nervous system (CNS) side effects, and anticholinergic side effects. Regarding the network estimates, the probability of being associated with the highest adverse outcome risk was estimated for each treatment comparison.

RESULTS

Fifty-one randomized clinical trials with 14 individual sgAHs and different dosing regimens, involving 7502 participants, were included. On the basis of the findings from network meta-analyses, variations in sgAH treatment comparisons were observed regarding the unacceptability of treatment, tolerability, adverse events, and CNS side effects. There were no statistically significant differences between the results of sgAH treatment for serious adverse events and those for anticholinergic side effects. On the basis of the ranking of safety profiles, emedastine 4 mg, mizolastine 10 mg, and cetirizine 10 mg were the top 3 ranked treatments with unfavorable safety profiles associated with CNS side effects and any adverse events.

CONCLUSIONS

These findings suggest evidence of variations in safety profiles among sgAHs for CU treatment, particularly in terms of adverse events and CNS side effects.

Adjunct therapy with probiotics for chronic urticaria in children: randomised placebo-controlled trial

Backgrounds

Chronic urticaria is a common disorder of the skin, characterised by recurrent skin wheals and angioedema. Recent reports have shown that altered diversity and composition of the gut microbiota may lead to imbalances in immune regulation, a causal factor in the occurrence of chronic urticaria.

Objective

This study aimed to evaluate the efficacy of the Yimingjia^® probiotic formula in the adjuvant treatment of chronic urticaria in children.

Methods

We enrolled 206 children with confirmed diagnoses of chronic urticaria and randomly assigned them to the treatment (n = 104) or placebo group (n = 102). The children in each group were treated with desloratadine dry suspension, and those in the treatment group also received Yimingjia^®. Clinical efficacy was evaluated at 1, 2 and 4 weeks.

Results

Clinical symptom scores did not differ significantly at weeks 1 and 2 (p > 0.05), but at 4 weeks, wheal size and attack frequency were significantly reduced in the treatment group (p = 0.049 and 0.03, respectively). The overall response rate (significant improvement + complete response) significantly differed between the treatment (80.8%) and placebo groups (62.5%) (χ² = 4.20, p = 0.04).

Conclusion

Adjunct therapy with Yimingjia^® was safe and effective at 4 weeks in the treatment of chronic urticaria in children. The study was registered under trial number NCT03328897.

BSACI guideline for the management of chronic urticaria and angioedema

This guidance for the management of patients with chronic urticaria and angioedema has been prepared by the Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI). The guideline is based on evidence as well as on expert opinion and is aimed at both adult physicians and paediatricians practising in allergy. The recommendations are evidence graded. During the development of these guidelines, all BSACI members were included in the consultation process using a Web-based system. Their comments and suggestions were carefully considered by the Standards of Care Committee. Where evidence was lacking, a consensus was reached by the experts on the committee. Included in this management guideline are clinical classification, aetiology, diagnosis, investigations, treatment guidance with special sections on children with urticaria and the use of antihistamines in women who are pregnant or breastfeeding. Finally, we have made recommendations for potential areas of future research.

Antihistamines and itch

Histamine is one of the best-characterized pruritogens in humans. It is known to play a role in pruritus associated with urticaria as well as ocular and nasal allergic reactions. Histamine mediates its effect via four receptors. Antihistamines that block the activation of the histamine H₁receptor, H₁R, have been shown to be effective therapeutics for the treatment of pruritus associated with urticaria, allergic rhinitis, and allergic conjunctivitis. However, their efficacy in other pruritic diseases such as atopic dermatitis and psoriasis is limited. The other histamine receptors may also play a role in pruritus, with the exception of the histamine H₂receptor, H₂R. Preclinical evidence indicates that local antagonism of the histamine H₃receptor, H₃R, can induce scratching perhaps via blocking inhibitory neuronal signals. The histamine H₄receptor, H₄R, has received a significant amount of attention as to its role in mediating pruritic signals. Indeed, it has now been shown that a selective H₄R antagonist can inhibit histamine-induced itch in humans. This clinical result, in conjunction with efficacy in various preclinical pruritus models, points to the therapeutic potential of H₄R antagonists for the treatment of pruritus not controlled by antihistamines that target the H₁R.

H1-antihistamines for chronic spontaneous urticaria

Background Chronic spontaneous urticaria (CSU) is characterised by the development of crops of red, itchy, raised weals or hives with no identifiable external cause.Objectives To assess the effects of H1-antihistamines for CSU.Search methods We searched the following databases up to June 2014: Cochrane Skin Group Specialised Register, CENTRAL (2014, Issue 5), MEDLINE(from 1946), EMBASE (from 1974) and PsycINFO (from 1806). We searched five trials registers and checked articles for references to relevant randomised controlled trials.Selection criteria We included randomised controlled trials of H1-antihistamines for CSU. Interventions included single therapy or a combination of H1-antihistamines compared with no treatment (placebo) or another active pharmacological compound at any dose.Data collection and analysis We used standard methodological procedures as expected by The Cochrane Collaboration.Our primary outcome measures were proportion of participants with complete suppression of urticaria: 'good or excellent' response,50% or greater improvement in quality of life measures, and adverse events.We present risk ratios (RR) with 95% confidence intervals(CIs). Main results We identified 73 studies (9759 participants); 34 studies provided data for 23 comparisons. The duration of the intervention was up to two weeks (short-term) or longer than two weeks and up to three months (intermediate-term).Cetirizine 10mg once daily in the short term and in the intermediate term led to complete suppression of urticaria by more participants than was seen with placebo (RR 2.72, 95% CI 1.51 to 4.91). For this same outcome, comparison of desloratadine versus placebo in the intermediate term (5 mg) (RR 37.00, 95% CI 2.31 to 593.70) and in the short term (20 mg) (RR 15.97, 95% CI 1.04 to 245.04)favoured desloratadine, but no differences were seen between 5 mg and 10 mg for short-term treatment.Levocetirizine 20 mg per day (short-term) was more effective for complete suppression of urticaria compared with placebo (RR 20.87,95% CI 1.37 to 317.60), and at 5 mg was effective in the intermediate term (RR 52.88, 95% CI 3.31 to 843.81) but not in the shortterm, nor was 10 mg effective in the short term.Rupatadine at 10 mg and 20 mg in the intermediate term achieved a 'good or excellent response' compared with placebo (RR 1.35,95% CI 1.03 to 1.77).Loratadine (10 mg) versus placebo (RR 1.86, 95% CI 0.91 to 3.79) and loratadine (10 mg) versus cetirizine (10 mg) (RR 1.05, 95%CI 0.76 to 1.43) over short-term and intermediate-term treatment showed no significant difference for 'good or excellent response' or for complete suppression of urticaria, respectively.Loratadine (10 mg) versus desloratadine (5 mg) (intermediate-term) showed no statistically significant difference for complete suppression of urticaria (RR 0.91, 95% CI 0.78 to 1.06) or for 'good or excellent response' (RR 1.04, 95% CI 0.64 to 1.71). For loratadine(10 mg) versus mizolastine (10 mg) (intermediate-term), no statistically significant difference was seen for complete suppression of urticaria (RR 0.86, 95% CI 0.64 to 1.16) or for 'good or excellent response' (RR 0.88, 95% CI 0.55 to 1.42).Loratadine (10mg) versus emedastine (2mg) (intermediate-term) showed no statistically significant difference for complete suppression(RR 1.04, 95% CI 0.78 to 1.39) or for 'good or excellent response' (RR 1.09, 95% CI 0.96 to 1.24); the quality of the evidence was moderate for this comparison.No difference in short-term treatment was noted between loratadine (10mg) and hydroxyzine (25mg) in terms of complete suppression(RR 1.00, 95% CI 0.32 to 3.10).When desloratadine (5 to 20 mg) was compared with levocetirizine (5 to 20 mg), levocetirizine appeared to be the more effective (P value < 0.02).In a comparison of fexofenadine versus cetirizine, more participants in the cetirizine group showed complete suppression of urticaria(P value < 0.001).Adverse events leading to withdrawals were not significantly different in the following comparisons: cetirizine versus placebo at 10 mg and 20 mg (RR 3.00, 95% CI 0.68 to 13.22); desloratadine 5 mg versus placebo (RR 1.46, 95% CI 0.42 to 5.10); loratadine 10 mg versus mizolastine 10 mg (RR 0.38, 95% CI 0.04 to 3.60); loratadine 10mg versus emedastine 2mg (RR 1.09, 95%CI 0.07 to 17.14);cetirizine 10 mg versus hydroxyzine 25 mg (RR 0.78, 95% CI 0.25 to 2.45); and hydroxyzine 25 mg versus placebo (RR 3.64, 95%CI 0.77 to 17.23), all intermediate term.No difference was seen between loratadine 10 mg versus mizolastine 10 mg in the proportion of participants with at least 50%improvement in quality of life (RR 3.21, 95% CI 0.32 to 32.33).Authors' conclusions Although the results of our review indicate that at standard doses of treatment, several antihistamines are effective when compared with placebo, all results were gathered from a few studies or, in some cases, from single-study estimates. The quality of the evidence was affected by the small number of studies in each comparison and the small sample size for many of the outcomes, prompting us to downgrade the quality of evidence for imprecision (unless stated for each comparison, the quality of the evidence was low).No single H1-antihistamine stands out as most effective. Cetirizine at 10 mg once daily in the short term and in the intermediate term was found to be effective in completely suppressing urticaria. Evidence is limited for desloratadine given at 5 mg once daily in the intermediate term and at 20 mg in the short term. Levocetirizine at 5 mg in the intermediate but not short term was effective for complete suppression. Levocetirizine 20 mg was effective in the short term, but 10 mg was not. No difference in rates of withdrawal due to adverse events was noted between active and placebo groups. Evidence for improvement in quality of life was insufficient.

Methods report on the development of the 2013 revision and update of the EAACI/GA2 LEN/EDF/WAO guideline for the definition, classification, diagnosis, and management of urticaria

This methods report describes the process of guideline development in detail. It is the result of a systematic literature review using the 'Grading of Recommendations Assessment, Development and Evaluation' (GRADE) methodology and a structured consensus conference held on 28 and 29 November 2012, in Berlin. It is a joint initiative of the Dermatology Section of the European Academy of Allergy and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA(2) LEN), the European Dermatology Forum (EDF), and the World Allergy Organization (WAO) with the participation of delegates of 21 national and international societies. This guideline covers the definition and classification of urticaria, taking into account the recent progress in identifying its causes, eliciting factors and pathomechanisms. In addition, it outlines evidence-based diagnostic and therapeutic approaches for the different subtypes of urticaria. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS) and is published in Allergy 2014; 69:868-887.

Urticaria and its subtypes: the role of second-generation antihistamines

Urticaria is a heterogeneous group of debilitating skin disorders characterized by wheals, pruritus, and frequently angioedema. The various forms of urticaria are often chronic and can exact a toll on quality of life. New diagnostic criteria and management guidelines are available to assist primary care physicians in the identification and proper treatment of different subtypes of urticaria. Second-generation antihistamines are recommended as first-line therapy because of their high degree of efficacy and safety. It is important to note, however, that European indications for most agents in this class are limited to specific forms of urticaria. The exception is desloratadine, the only second-generation antihistamine approved for the treatment of all urticaria subtypes in the European Union. Guidelines and best practice suggest that doses of antihistamines up to 4 times higher than those normally recommended for urticaria may benefit patients who do not respond to standard doses of antihistamines. Adjunctive therapy with leukotriene receptor antagonists may be advantageous in certain subgroups of patients who have suboptimal responses to antihistamine monotherapy. In all cases, physicians should work closely with patients to ensure proper adherence to prescribed regimens-a component that is often lacking but holds the key to successful outcomes.

Chronic urticaria: a comparison of management guidelines

INTRODUCTION

Chronic urticaria is characterized by recurring episodes of spontaneous transient dermal wheals and pruritus, with or without angioedema, which can persist for ≥ 6 weeks. Chronic urticaria impairs quality of life, emphasizing the need for effective treatments. Professional societies and clinical experts have issued evidence-based recommendations for the management of chronic urticaria, including recommending the use of second-generation antihistamines as a first-line therapy.

AREAS COVERED

A Medline search was conducted from 2000 to 2011 using the following terms, alone or in combination: 'chronic urticaria', 'management guidelines', 'consensus guidelines' and 'expert opinions'. Ten management guidelines/expert opinions met the inclusion criteria.

EXPERT OPINION

There was a universal agreement among the articles reviewed, that low-sedating, second-generation antihistamines should be prescribed as a first-line treatment of chronic urticaria. For refractory urticaria, however, recommendations varied and included dose escalation of second-generation antihistamines and adjunctive treatments with other agents of the same class, such as sedating antihistamines or leukotriene receptor antagonists. More research into effective second-line treatments and consistent implementation of current guidelines is needed, to ensure that treatment is based on clinical evidence.

Unmet clinical needs in chronic spontaneous urticaria. A GA²LEN task force report

Chronic spontaneous urticaria, formerly also known as chronic idiopathic urticaria and chronic urticaria (CU), is more common than previously thought. At any time, 0.5-1% of the population suffers from the disease (point prevalence). Although all age groups can be affected, the peak incidence is seen between 20 and 40 years of age. The duration of the disease is generally 1-5 years but is likely to be longer in more severe cases, cases with concurrent angioedema, in combination with physical urticaria or with a positive autologous serum skin test (autoreactivity). Chronic spontaneous urticaria has major detrimental effects on quality of life, with sleep deprivation and psychiatric comorbidity being frequent. It also has a large impact on society in terms of direct and indirect health care costs as well as reduced performance at work and in private life. In the majority of patients, an underlying cause cannot be identified making a causal and/or curative treatment difficult. Nonsedating H₁-antihistamines are the mainstay of symptomatic therapy, but treatment with licensed doses relieves symptoms effectively in < 50% of patients. Although guideline-recommended updosing up to fourfold increases symptom control in many patients, a substantial number of patients have only little benefit from H₁ -antihistamines. Consequently, there is a great need for new therapeutic strategies.

Chronic urticaria: assessment of current treatment

Chronic urticaria is heterogenous, long-persisting and has a severe impact on quality of life and daily work. Effective treatment is essential but remains a confounding problem. This review summarizes available treatment strategies for chronic urticaria and their strength of evidence. Besides treatment of identified triggering factors such as chronic persistent bacterial infections (e.g., with Helicobacter pylori, streptococci, staphylococci or yersinia), standard treatment consists of nonsedating H1-antihistamines. Most patients require increasing (off-label) dosages that should be taken daily and regularly, however, this still fails in a third of cases. Reliable alternatives in the world literature are rare and the level of evidence is low. Certain subgroups may display benefit from additional treatment with cyclosporine A, cysteinyl leukotriene receptor antagonists, chloroquine, dapsone or other alternatives. A practicable step-wise treatment approach is given to optimize and individualize the treatment of patients with chronic urticaria.

EAACI/GA(2)LEN/EDF/WAO guideline: management of urticaria

This guideline, together with its sister guideline on the classification of urticaria (Zuberbier T, Asero R, Bindslev-Jensen C, Canonica GW, Church MK, Giménez-Arnau AM et al. EAACI/GA(2)LEN/EDF/WAO Guideline: definition, classification and diagnosis of urticaria. Allergy 2009;64: 1417-1426), is the result of a consensus reached during a panel discussion at the Third International Consensus Meeting on Urticaria, Urticaria 2008, a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA(2)LEN), the European Dermatology Forum (EDF) and the World Allergy Organization (WAO). As members of the panel, the authors had prepared their suggestions regarding management of urticaria before the meeting. The draft of the guideline took into account all available evidence in the literature (including Medline and Embase searches and hand searches of abstracts at international allergy congresses in 2004-2008) and was based on the existing consensus reports of the first and the second symposia in 2000 and 2004. These suggestions were then discussed in detail among the panel members and with the over 200 international specialists of the meeting to achieve a consensus using a simple voting system where appropriate. Urticaria has a profound impact on the quality of life and effective treatment is, therefore, required. The recommended first line treatment is new generation, nonsedating H(1)-antihistamines. If standard dosing is not effective, increasing the dosage up to four-fold is recommended. For patients who do not respond to a four-fold increase in dosage of nonsedating H(1)-antihistamines, it is recommended that second-line therapies should be added to the antihistamine treatment. In the choice of second-line treatment, both their costs and risk/benefit profiles are most important to consider. Corticosteroids are not recommended for long-term treatment due to their unavoidable severe adverse effects. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS).

Inhibition of the histamine-induced weal and flare response: a valid surrogate measure for antihistamine clinical efficacy?

Histamine plays a central role in allergic responses. Inhibition of the weal and flare response to histamine is a traditional pharmacodynamic tool to measure the activity of H(1)-receptor antagonists. The time course and duration of cutaneous weal and flare inhibition are often used as surrogate measures of clinical efficacy. Pharmacodynamic differences among antihistamines are often interpreted to indicate differences in clinical efficacy. A systematic review of literature from 1980 to 2006 regarding the histamine induced weal and flare was undertaken. Search terms included 'histamine', 'skin test', 'weal', 'flare', and 'antihistamine'; retrieved articles were searched for relevant studies not identified initially. Data from human studies on the inhibition of the weal and flare by second-generation antihistamines were extracted and assessed. A literature search from 1980 to 2006 was undertaken for comparative studies of second-generation antihistamines in the clinical settings of allergic rhinitis (AR) and chronic idiopathic urticaria; data extracted from these studies underwent systematic review. Differences were noted among second-generation antihistamines in terms of their ability to inhibit the histamine-induced weal and flare. Corresponding differences in terms of clinical efficacy in AR and chronic urticaria were not identified following a systematic review. The reasons for the disconnect between pharmacodynamic effects and clinical efficacy may include differences between the route and concentration of histamine, the involvement of mediators other than histamine in the allergic response, and the short time course of pharmacodynamic studies. The histamine-induced weal and flare response is a pharmacodynamic test that should not be used to compare the clinical efficacy of different antihistamines, and is not an adequate alternative to clinical end-point assessments in AR or chronic idiopathic urticaria.

Desloratadine for chronic idiopathic urticaria: a review of clinical efficacy

Chronic idiopathic urticaria (CIU) is a disabling affliction that considerably limits patients' daily activities and interferes with sleep. Clinical studies have shown that histamine H1-receptor antagonists (antihistamines) are highly effective for inhibiting the hives/wheals and pruritus associated with CIU, as well as improving patients' quality of life. Desloratadine is a rapid-acting, once-daily, nonsedating selective H1-receptor antagonist/inverse receptor agonist with proven clinical efficacy in patients with CIU. It has 10-20 times the in vivo H1 receptor-binding affinity of loratadine, its parent compound, and 52-194 times the H1 receptor-binding affinity of cetirizine, ebastine, loratadine, and fexofenadine. Desloratadine displays linear pharmacokinetics after oral administration. Age and sex have no apparent effect on the drug's metabolism and elimination, and food does not affect its bioavailability or absorption. Desloratadine also exerts anti-inflammatory effects via mechanisms that are independent of H1-receptor antagonism. Results from randomized, double-blind, placebo-controlled studies of 6 weeks' duration in adults and adolescents with moderate-to-severe CIU indicate that desloratadine significantly minimizes the severity of pruritus, reduces the number and size of hives, and improves disease-impaired sleep and daily activities. Improvements were noted after a single dose of desloratadine and were maintained over 6 weeks of treatment. Desloratadine was safe and well tolerated in clinical trials of patients with CIU. The adverse effect profile of desloratadine in adults, as well as in children aged from 6 months to 11 years, is comparable to that of placebo. Evaluations of cognitive and psychomotor performance in adults indicate no impairment of function with dosages of desloratadine 5 mg/day. In conclusion, desloratadine is an important therapeutic option for prompt and enduring symptom relief in patients with moderate-to-severe CIU. In addition to efficacy and safety, desloratadine affords a convenient administration regimen, rapid onset of action, and an absence of drug-drug or drug-food interactions. Other important prescribing considerations are that, unlike all first-generation and some second-generation antihistamines, desloratadine is nonsedating at its clinically approved dosage and does not impair psychomotor function.

Urticaria and angioedema

Urticaria and angioedema are commonly encountered complaints in children. Although the diagnosis is clear, establishing an etiology, especially with respect to chronic urticaria, can be challenging. A significant proportion of chronic urticarial cases are now considered to have an autoimmune etiology. This article reviews progress in the field of urticaria and angioedema including developments in pathogenesis, description of laboratory testing, and review of medications. Urticaria and angioedema can usually be controlled by avoidance of triggers, a variety of supportive medications, and reassurance.

Advances in the treatment of chronic urticaria

There have been a number of exciting developments in the treatment of allergic diseases in recent years, but the development of new treatments for urticaria has lagged behind. The standard treatment for chronic urticaria (CU) involves the use of H1 antagonists. A number of small but promising studies have found potential benefit with medications that are used less often. This article reviews the established therapies for CU and the experimental evidence for the use of nonstandard and relatively unknown therapies. The potential usefulness of some of the new allergy medications for the treatment of CU also is discussed.

Mizolastine in primary acquired cold urticaria

BACKGROUND

Treatment of primary acquired cold urticaria (CU) is quite difficult because of variable clinical effectiveness and side effects of classic antihistamines.

OBJECTIVE

The objective of the study was to assess the efficacy and safety of mizolastine, an antihistaminic with antiallergic properties, versus placebo in primary acquired CU.

METHODS

This study was a phase II, multicenter, randomized, double-blind, crossover, placebo-controlled study of mizolastine (10 mg, once daily) versus placebo in 28 patients with primary acquired CU. Efficacy was measured by the cold-stimulation time test, the wheal response, and pruritus intensity after an ice-cube test.

RESULTS

Mizolastine delayed the cold-induced wheal reaction, reduced wheal response at 3 and 10 minutes, and reduced pruritus intensity. Statistically significant differences were observed versus placebo for the cold-stimulation time test, wheal response at 3 and 10 minutes, and pruritus intensity (P =.006,.015,.009, and.005, respectively). No clinically relevant adverse events were reported.

CONCLUSIONS

Mizolastine (10 mg, once daily) was shown to be superior to placebo for both delaying and reducing the cold-induced wheal reaction without significant adverse events. Results suggest that mizolastine may be effective in the treatment of CU.

Clinical pharmacology of H1-antihistamines in the skin

BACKGROUND

The extent of the distribution of H(1)- antihistamines into the skin and H(1)-antihistamine activity in the skin are clinically relevant in the treatment of allergic skin disorders.

METHODS

In a prospective, randomized, double-blind, parallel-group, multiple-dose study, we gave fexofenadine 180 mg, loratadine 10 mg, or chlorpheniramine 8 mg to 21 men (7 in each group). Before dosing and at 1, 3, 6, 9, and 24 hours after the first antihistamine dose as well as at 168, 192, and 216 hours after the first dose (ie, 12, 36, and 60 hours after the seventh and last consecutive daily H(1)-antihistamine dose), we measured fexofenadine, loratadine, or chlorpheniramine concentrations in plasma and in skin tissue samples obtained through use of punch biopsies, along with suppression of histamine-induced skin wheals and flares. Loratadine metabolites, including desloratadine and its metabolites, were not measured, and chlorpheniramine metabolites were not measured.

RESULTS

All 21 participants completed the study. Skin/plasma fexofenadine ratios ranged from 1.2 +/- 0.5 at 1 hour to 110 +/- 74 at 24 hours, and skin fexofenadine concentrations exceeded loratadine and chlorpheniramine skin concentrations at each test time. This was reflected in significant wheal and flare suppression by fexofenadine in comparison with loratadine at 3 hours and in comparison with chlorpheniramine at 6 and 9 hours (wheal) and from 3 to 24 hours and at 192 hours (flare). Compared with fexofenadine, loratadine significantly suppressed the wheal at 192 hours, and compared with chlorpheniramine, it significantly suppressed the wheal at 9 hours and the flare at 24 and 192 hours. At no time did chlorpheniramine suppress the wheal or flare significantly more than fexofenadine or loratadine.

CONCLUSIONS

In skin disorders for which H(1)-antihistamines are recommended, these results support the use of fexofenadine or loratadine, and they indicate the need for reexamination of the use of chlorpheniramine.

Antihistamines in late-phase clinical development for allergic disease

Allergic rhinitis (AR) is a global health concern and shares a high comorbidity with asthma. Recent research suggests that different allergic diseases, such as AR, asthma, allergic conjunctivitis and chronic idiopathic urticaria (CIU), are evoked by common pathological mechanisms characterised by the release of histamine and other inflammatory mediators. Although H(1) receptor antagonists are the mainstay of therapy for allergic disease, the unacceptably high incidence of anticholinergic and CNS-related side effects of first-generation H(1) antagonists led to the search for improved second-generation H(1) antagonists. While many of these agents were largely devoid of CNS side effects, their tendency for drug-drug interactions (e.g., terfenadine and astemizole) resulted in an increased incidence of cardiotoxicity. Furthermore, second-generation H(1) antagonists exhibited weak anti-inflammatory properties and had no effect on nasal congestion. These observations emphasised the need for newer anti-allergic agents with a broader spectrum of activity and an improved safety profile. Among the newer H(1) antagonists currently in clinical development, desloratadine and mizolastine are the most widely studied. Both have a rapid onset of action, and desloratadine has demonstrated clinical efficacy in AR, CIU and seasonal asthma. Desloratadine has several advantages over other H(1) antagonists in that it has proven decongestant activity, a sparing effect on the use of bronchodilators (beta(2)-agonists) and a low potential for drug interactions. The broad anti-inflammatory properties of desloratadine and mizolastine, which distinguish these agents from other H(1) antagonists in clinical development (e.g., norastemizole and levocetirizine), suggest they may have a more profound impact on the underlying disease in patients suffering from different forms of allergy. The lack of clinical efficacy and safety data on rupatadine and HSR-609, both novel H(1) antagonists, precludes an accurate assessment of their potential for treating allergic disease. Epinastine and efletirizine are being developed exclusively for topical application and are unlikely to play a significant role in the management of allergic diseases as a whole.

Treatment of urticaria. An evidence-based evaluation of antihistamines

Urticaria is a cutaneous syndrome characterized by dermal edema (wheal) and erythema (flare) that blanches with pressure. The lesions typically last less than 24 hours and are usually pruritic. In 1983, Christensen and Maibach summarized the theory behind the use of histamine H1 receptor antagonists (antihistamines) in clinical dermatology. These agents remain the mainstay of treatment for urticaria. This article reviews the medical literature on the effectiveness of antihistamines in urticarial syndromes, including acute, chronic idiopathic and the physical urticarias. Older antihistamines, such as chlorpheniramine and hydroxyzine, are effective in the treatment of urticarias, but they also have marked sedative and anticholinergic effects. Newer nonsedating antihistamines (second-generation antihistamines) have been developed that have reduced adverse effects because they do not cross the blood-brain barrier; these agents (acrivastine, cetirizine, loratadine, mizolastine, fexofenadine, ebastine, azelastine and epinastine) cause significantly less sedation and psychomotor impairment than their older counterparts. A review of the literature reveals that there are few studies which document the efficacy of second-generation antihistamines in the treatment of acute urticaria, a biologic entity that usually resolves within 3 weeks. We did not identify controlled studies that suggested superiority of any antihistamine in the treatment of acute urticaria. Loratadine or cetirizine, and possibly mizolastine, appear to be treatments of choice for chronic idiopathic urticaria. For symptomatic dermatographism, the combination of an antihistamine and an H2 antagonist, e.g. chlorpheniramine and cimetidine, appears to be effective. Very few studies have been conducted on the use of antihistamines in the treatment of cold, cholinergic, and pressure urticaria. Antihistamines are the mainstay of urticarial therapy. This evidence-based review suggests that there are efficacy differences between newer, nonsedating antihistamines and older agents in some forms of the disorder. Clearly, further well-controlled clinical trials in larger numbers of patients are needed to clarify the role of these agents in the treatment of urticaria.

Clinical advantages of dual activity in urticaria

Urticaria is a common disorder that adversely affects quality of life; work-related and recreational activities are restricted, while rest, sleep, and emotions are seriously disturbed in a significant proportion of patients. The pathogenic mechanisms vary, but cutaneous mast-cell activation with release of histamine and other vasoactive or proinflammatory mediators is thought to be the final common pathway for lesion induction in most cases. A subsequent, but incompletely understood, late-phase allergic reaction seems to prolong the inflammatory process, particularly in certain chronic forms of the disorder. Although histamine is considered an important mediator of urticaria, additional substances, including the cysteinyl leukotrienes (LTs), are putative mediators of the immediate urticarial responses and the inflammatory events that follow in some types of urticaria. A second-generation antihistamine, mizolastine, which exhibits dual activity with selective H1-receptor antagonism and, as shown in animal studies, anti-5-lipoxygenase activity, represents an advance in the treatment of urticaria. It has rapid, potent and sustained action. At the recommended 10-mg dose, mizolastine suppresses the histamine-induced wheal reaction as early as 1 h after oral administration. Compared to placebo, mizolastine significantly reduces overall patient discomfort and pruritus in patients with chronic idiopathic urticaria. Double-blind, placebo-controlled studies have also shown mizolastine to be at least as effective as other second-generation antihistamines. Furthermore, with long-term use of mizolastine over 1 year, a reduction in pruritus and the number of urticarial episodes was maintained with no evidence of tachyphylaxis or tolerance. Mizolastine has also been shown to be an effective treatment for cold-induced urticaria, causing significant delay in the whealing response to the ice-cube test and also reducing the wheal diameter.

Mizolastine is effective and well tolerated in long-term treatment of perennial allergic rhinoconjunctivitis. Riperex Study Group

The aim of this study was to determine the long-term efficacy and safety of mizolastine, a new second-generation antihistamine with European approval, in the treatment of perennial allergic rhinoconjunctivitis. In this study, 141 patients were treated with once-daily mizolastine 10 mg or 15 mg in a 5-month open-label extension of a 1-month double-blind, placebo-controlled trial, which assessed once-daily mizolastine 10 mg. Mizolastine significantly reduced the nasal subscore (sneezing, rhinorrhoea, itch; end-baseline +/- SD, -2.5 +/- 6.3), nasal obstruction (-1.2 +/- 2.6) and rhinoscopy scores (-1.3 +/- 2.6), and improved ocular and total nasal scores after 6 months' treatment. Improvement was maintained for the duration of the study with no loss of drug efficacy. Adverse effects were mild with no specific effects associated with prolonged use. These results clearly demonstrate that mizolastine is effective and well tolerated in the long-term treatment of perennial allergic rhinoconjunctivitis. The significant clinical improvement in nasal blockade may reflect mizolastine's histamine/5-lipoxygenase dual inhibition.