Efficacy of different oral H1 antihistamine treatments on allergic rhinitis: a systematic review and network meta-analysis of randomized controlled trials

Abstract Introduction Oral H1 antihistamines are the first-line treatment for patients with allergic rhinitis, while it is uncertain which kind and dosage of the antihistamines are more effective in improving symptoms of patients. Objective To evaluate the efficacy of different oral H1 antihistamine treatments on patients with allergic rhinitis by performing a network meta-analysis. Methods The search was executed in PubMed, Embase, OVID, the Cochrane Library and ClinicalTrials.gov for relevant studies. The network meta-analysis was performed by using Stata 16.0, and the outcome measures of the analysis were symptom score reductions of patients. Relative risks with 95% Confidence Intervals were used in the network meta-analysis to compare the clinical effect of treatments involved, and Surface Under the Cumulative Ranking Curves (SUCRAs) were also calculated to rank the treatments' efficacy. Results 18 eligible randomized controlled studies, involving a total of 9419 participants, were included in this meta-analysis. All the antihistamine treatments outperformed placebo in total symptom score reduction and each individual symptom score reduction. According to the results of SUCRA, rupatadine 20 mg and rupatadine 10 mg were ranked relatively high in reductions of total symptom score (SUCRA: 99.7%, 76.3%), nasal congestion score (SUCRA: 96.4%, 76.4%), rhinorrhea score (SUCRA: 96.6%, 74.6%) and ocular symptom score (SUCRA: 97.2%, 88.8%); rupatadine 20 mg and levocetirizine 5 mg were ranked relatively high in reductions of nasal itching score (SUCRA: 84.8%, 83.4%) and sneezing score (SUCRA: 87.3%, 95.4%); loratadine 10 mg was ranked the lowest in each symptom score reduction besides placebo. Conclusion This study suggests that rupatadine is the most effective in alleviating symptoms of patients with allergic rhinitis among different oral H1 antihistamine treatments involved, and rupatadine 20 mg performs better than rupatadine 10 mg. While loratadine 10 mg has inferior efficacy for patients to the other antihistamine treatments.

Clinical difference between single subtype and mixed subtype chronic urticaria: A retrospective study

Background: The subtypes of chronic urticaria share a common clinical expression, but may show differences phenotypically. Meanwhile, two or more different subtypes of chronic urticaria can coexist in any given patient which may involve different phenotypes. Aims: The study aims to compare the two phenotypes in terms of demographics, clinical profile and treatment response. Methods: In this retrospective study, 2678 chronic urticaria patients were divided into the single subtype chronic urticaria group and mixed subtype chronic urticaria group as was appropriate.The differences in the clinical features, possible causes, urticaria activity score of seven days, dermatology life quality index score, laboratory investigations and response to treatments were evaluated among the two groups. Results: An obvious female predominance was detected in chronic urticaria, especially in mixed subtype chronic urticaria patients. Of the 2678 chronic urticaria patients, there were 837(31.25%) mixed subtype chronic urticaria. Chronic spontaneous urticaria combined with symptomatic dermographism was the most common group in the mixed subtype chronic urticaria. Patients with mixed subtype chronic urticaria were more likely to have associated chest tightness/shortness of breath and showed greater urticaria activity. In patients with single subtype chronic urticaria, the positive rate of family history with allergic rhinitis, asthma or urticaria was lower. Based on evaluation of the treatment, control with second-generation antihistamines at licensed doses was achieved in only 38.83% of mixed subtype chronic urticaria patients, compared with 56.32% of patients with single subtype. Limitations: First, this study was a single-center design retrospective study. Second, omalizumab treatment was not included. Third, the differences between different subtypes of mixed subtype chronic urticaria were not discussed in detail. Conclusion: This study showed that mixed subtype chronic urticaria had some distinct features. Comprehensive knowledge about it may help us define effective therapeutic strategies and improve symptom control and the quality of life for chronic urticaria patients

Urticária aquagênica: relato de caso e revisão de literatura / Aquagenic urticaria: a case report and literature review

A urticária aquagênica é uma forma rara de urticária crônica induzida (UCInd) desencadeada por um estímulo específico. A patogênese não é totalmente compreendida, mas os sintomas se iniciam minutos após a exposição cutânea à água, independentemente de sua temperatura, e as urticas têm o padrão foliculocêntricas. O diagnóstico é confirmado através do teste de provocação, e o tratamento de primeira linha são os anti-histamínicos de segunda geração. Neste artigo, relatamos um caso de urticária aquagênica e fazemos uma breve revisão da literatura sobre o tema.

Aquagenic urticaria is a rare form of chronic inducible urticaria (CIndU) triggered by a specific stimulus. Pathogenesis is not fully understood, but symptoms appear minutes after cutaneous exposure to water, regardless of temperature, and wheals have a folliculocentric pattern. The diagnosis of CIndU is confirmed by provocation testing using established protocols, and first-line treatment is second-generation antihistamines. In this article, we report a case of aquagenic urticaria and provide a brief review of the relevant literature.

Synergistic Effect of H1-Antihistamines on Topical Corticosteroids for Pruritus in Atopic Dermatitis: A Systematic Review and Meta-Analysis

BACKGROUND: Although oral antihistamines (H1-histamine receptor antagonists) are the main treatment option for pruritus in general skin dermatosis, their effect in treating pruritus of atopic dermatitis (AD) has not yet been established. OBJECTIVE: We conducted a systematic review and meta-analysis to evaluate the effectiveness of combined therapy of H1-antihistamines and topical steroids. METHODS: We systematically searched MEDLINE, Embase, and CENTRAL databases for articles published from 1967 to 2015. We identified 1,206 studies and assessed their titles, abstract, and full-text. Random effects meta-analysis was used to calculate mean differences (MD) with 95% confidence intervals (CI). RESULTS: Two studies satisfying the inclusion criteria of antihistamine therapy with mandatory topical steroid use were selected. Comparing antihistamine monotherapy with combination therapy, patients treated with the addition of antihistamine to topical corticosteroids showed a statistically significant clinical improvement (standard MD, −0.24; 95% CI, −0.42 to −0.05; p=0.01). CONCLUSION: H1-antihistamines may have a synergistic effect when combined with topical steroids by influencing various associative factors of chronic pruritus in AD.

Anaphylaxis to Chlorpheniramine Maleate and Literature Review

Chlorpheniramine maleate is commonly used antihistamine. Since antihistamines are the main therapeutic agents for symptomatic treatment of urticaria, anaphylaxis to antihistamines may lead to errors in diagnosis and treatment. We report a case of anaphylaxis induced by chlorpheniramine maleate confirmed by intradermal test. A 35-year-old female experienced history of anaphylaxis after intramuscular injection of chlorpheniramine maleate. Skin prick test was negative, but intradermal test was positive. Patient also experienced mild dizziness after intradermal test and refused to perform any further evaluation such as oral challenge test. Anaphylaxis for chlorpheniramine maleate is very rare but should be considered.

Role of H1 receptor in inflammatory response during ventilator-induced lung injury in rats / 中华麻醉学杂志

Objective To evaluate the role of H1 receptor in inflammatory responses during ventila-tor-induced lung injury ( VILI) in rats. Methods Thirty clean-grade healthy male Sprague-Dawley rats, aged 9-10 weeks, weighing 250-300 g, were divided into 3 groups ( n=10 each) using a random number table method: control group (group C), VILI group (group V) and H1 receptor antagonist clemastine group ( group Cle) . The animals were anesthetized and tracheostomized, and the rats in group C kept spon-taneous breathing. The rats were mechanically ventilated for 4 h with the tidal volume of 40 ml/kg, respira-tory rate 40 breaths/min, inspiratory/expiratory ratio 1 : 1, and inspired oxygen fraction ratio 21％ in group V. In group Cle, clemastine 0. 9 mg/kg was intramuscularly injected at 30 min before anesthesia, the ani-mals were tracheostomized after being anesthetized, and then the rats were mechanically ventilated with the same ventilator settings as group V. The animals were sacrificed at 4 h of ventilation, bronchoalveolar lav-age fluid ( BALF) was collected for determination of concentrations of total protein, interleukin-6 ( IL-6) , tumor necrosis factor-alpha ( TNF-α) , and the lung specimens were obtained for microscopic examination of pathologic changes and for determination of wet/dry weight ratio ( W/D ratio ) . Results Compared with group C, the concentrations of total protein, IL-6 and TNF-αin BALF and W/D ratio were significantly in-creased in group V (P＜0. 05). Compared with group V, the concentrations of total protein, IL-6 and TNF-αin BALF and W/D ratio were significantly decreased in group Cle ( P＜0. 05) . The pathologic chan-ges of lung tissues were significantly attenuated in group Cle as compared with group V. Conclusion H1 receptor is involved in the process of inflammatory responses during VILI in rats.

Effect of clemastine fumarate on TLR4/PI3K/Akt signaling pathway during hypoxia-reoxygenation in rat cardiomyocytes / 中华麻醉学杂志

Objective To evaluate the effect of clemastine fumarate on Toll-like receptor 4/phosphatidylinositol-3-kinase/serine-threonine kinase (TLR4/PI3K/Akt) signaling pathway during hypoxia-reoxygenation (H/R) in rat cardiomyocytes.Methods H9C2 cells of rats cultured in vitro were seeded in culture wells or dishes at a density of 1×105 cells/ml and divided into 3 groups (n=11 each) by using a random number table method:control group (group C),H/R group and clemastine fumarate group (CF group).Cardiomyocytes were exposed to 5％ CO2-95％ N2in a low-glucose DMEM medium at 37℃ for 4 h followed by 4 h reoxygenation.At 4 h of reoxygenation,the cell viability was detected by CCK-8 assay,the ultrastructure was observed with a transmission electron microscope,the expression of TLR4,PI3K,phosphorylated Akt (p-Akt) and caspase-3 was detected by Western blot,and the expression of TLR4,PI3K and caspase-3 was detected by immunofluorescence.Results Compared with group C,the cell viability was significantly decreased,the expression of TLR4 and caspase-3 was up-regulated,and the expression of PI3K and p-Akt was down-regulated in group H/R (P＜0.05).Compared with group H/R,the cell viability was significantly increased,the expression of TLR4 and caspase-3 was down-regulated,the expression of PI3K and p-Akt was up-regulated (P＜0.05),and the mitochondrial damage was significantly attenuated in group CF.Conclusion The mechanism by which clemastine fumarate alleviates H/R injury to rat cardiomyocytes may be related to inhibiting TLR4 expression and activating PI3K/Akt signaling pathway.

Suppression of wheal and flare in histamine test by the main H1 antihistamines commercialized in Brazil

Abstract: Background: Several dermatoses are mediated by histamine, such as urticaria, angioedema, and papular urticaria. There are no Brazilian studies comparing the potency of antihistamines. Objectives: To evaluate the tolerability and efficacy of the main commercial brand and generic H1 antihistamines, regarding the suppression of the wheal and flare to the histamine test. Methods: A quasi-experimental, open study with 10 healthy adults submitted to the histamine test on the ventral aspect of the forearms. After 20 minutes, wheal and flares were measured. The tests were performed after two hours of intake of dexchlorpheniramine, hydroxyzine, levocetirizine, fexofenadine, cetirizine, loratadine, ebastine, desloratadine, epinastine and rupatadine, as well as generics of loratadine, cetirizine and fexofenadine. Results: All antihistamines presented a reduction in the wheal compared to the control (p <0.02), as well as in the flare, except for rupatadine (p = 0.70). In the internal comparison, cetirizine, fexofenadine, epinastine, levocetirizine, dexchlorpheniramine and hydroxyzine were the most potent, with no difference between them (p > 0.1). As for halo, cetirizine, epinastine, hydroxyzine and fexofenadine were the most potent, with no difference between them (p > 0.1). The most common adverse effect was drowsiness, which was more prevalent among first-generation drugs (p < 0.01). Generic loratadine, fexofenadine and cetirizine halos were higher than their controls (p <0.03).. Study limitations: A single-center study evaluating only aspects related to histamine. Conclusions: Brazilian commercial antihistamines presented different profiles of inhibition of wheal and flares in the histamine test, as well as adverse effects. Generic loratadine, fexofenadine and cetirizine presented larger flares than brand drugs.

Acupoint Injection at "Yingxiang"(LI 20) and "Yintang"(GV 29) May Relieve Nasal Allergic Symptoms Possibly by Down-regulating Expression of Histamine Receptor H 1 and H 4 in Nasal Mucosa of Allergic Rhinitis Rats / 针刺研究

OBJECTIVE: To observe the effect of acupoint injection at "Yingxiang"(LI 20) and "Yintang"(GV 29) on nasal allergic reactions and the expression of histamine receptor H 1 and H 4 in nasal mucosa of allergic rhinitis (AR) rats, so as to reveal its mechanism underlying improvement of AR. METHODS: SD rats were randomized into normal, model, non-acupoint injection and acupoint injection groups (n=8 in each). The AR model was established by intraperitoneal (i.p.) injection of mixture of ovalbumin, aluminium hydroxide gel and normal saline (once every other day, for 7 times), and nasal drip of ovalbumin (on the following day of i.p.for 7 days). The mixture solution of lidocaine, dexamethasone (DXM) and transfer factor (0.1 mL/acupoint or non-acupoint) was injected into bilateral LI 20 and GV 29 in the acupoint injection group, or into the non-acupoints (about 5 cm below the armpit on both sides, and the middle point between the left "Houhai"[GV 1] and "Huantiao"[GB 30]), on the 1st , 5th, 9th, and 13th day after modeling. Symptoms of sneezing, nasal discharge, nose-rubbing, etc. were scored after the treatment. The expression levels of H1 R and H4 R proteins and genes in the nasal mucosa tissue were determined using immunohistochemistry and quantitative real-time PCR, respectively. RESULTS: Compared with the normal group, the symptom score and the expression levels of H1 R, H4 R proteins and genes in nasal mucosa were significantly increased in the model group (P0.05), suggesting a specificity of the effect of acupoint injection. CONCLUSION: Acupoint injection can relieve the allergic symptoms of AR rats, which may be related to its effects in down-regulating the over expression of H1 R and H4 R proteins and genes in the nasal mucosa.

Mastocitosis cutánea: reporte de un caso / Cutaneous mastocytosis: A case report

Introducción La mastocitosis representa un grupo de enfermedades caracterizadas por una acumulación excesiva de mastocitos en uno o múltiples tejidos. Puede limitarse a la piel o tener un compromiso sistémico, siendo de baja prevalencia y pronóstico benigno en la infancia. Objetivo Reportar un caso de urticaria pigmentosa como subtipo de mastocitosis cutánea y hacer una revisión bibliográfica enfocada en los hallazgos clínicos, el diagnóstico y el manejo inicial básico. Caso clínico Lactante de 6 meses de edad con múltiples máculas y pápulas de color café claro localizadas en el tronco, los brazos y las piernas, cuadro compatible con una urticaria pigmentosa, confirmada mediante biopsia. Se solicitaron exámenes para descartar compromiso sistémico. La paciente fue tratada con medidas generales, educación y antihistamínicos, con excelente evolución. Conclusiones La mastocitosis cutánea es una enfermedad poco común, de buen pronóstico. En la infancia generalmente bastan las medidas generales y educación para obtener resultados favorables. La terapia farmacológica de primera línea son los antagonistas H1.

Introduction Mastocytosis represents a group of diseases characterised by an excesive accumulation of mastocytes in one or multiple tissues. It can affect only the skin, or have a systemic involvement. It has a low prevalence, and the prognosis is benign in children. Objective To report a case of urticaria pigmentosa as a subtype of cutaneous mastocytosis, and present a literature review focused on clinical findings, diagnosis and initial basic management. Clinical case A child of six months of age presenting with multiple blemishes and light brown papules located on the trunk, arms and legs. The symptoms were compatible with urticaria pigmentosa, and was confirmed by biopsy. Tests to rule out systemic involvement were requested. The patient was treated with general measures, education, and antihistamines, with favourable results. Conclusions Cutaneous mastocytosis is a rare disease with a good prognosis. In childhood general measures and education are usually enough to obtain favourable results. Histamine H1 antagonists are the first line drug treatment.

Efficacy of clemastine fumarate in antagonizing atracurium-induced release of histamine in patients undergoing surgery under general anesthesia / 中华麻醉学杂志

Objective To evaluate the efficacy of clemastine fumarate in antagonizing atracuriuminduced release of histamine in the patients undergoing surgery under general anesthesia.Methods Eighty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients,aged 21-59 yr,with body mass index of 17-26 kg/m2,scheduled for elective modified radical mastectomy,were divided into 2 groups (n=40 each) using a random number table:control group (group C) and clemastine fumarat group (group CF).Clemastine fumarate 2 mg was injected intramuscularly at 20 min before induction of anesthesia.Anesthesia was induced with iv midazolam 0.1 mg/kg,etomidate 0.3 mg/kg,fentanyl 4-6 μg/kg and atracurium 0.8 mg/kg.The patients were mechanically ventilated after insertion of the larygeal mask airway.Anesthesia was maintained with inhalation of 2％ sevoflurane.Before administration of clemastine fumarate,at 20 min after administration,immediately before administration of atracurium,and at 2,5,10 and 20 min after administration of atracurium,arterial blood samples were taken for determination of plasma histamine concentrations,and the peak airway pressure and degree of cutaneous color were recorded.The development of histaminemia and adverse cardiovascular events was assessed.Steward recovery scores and Ramsay sedation scores were recorded at 10 min after removal of the laryngeal mask airway.Results The incidence of histaminemia was 60％ and 8％ in C and CF groups,respectively.Compared with group C,the plasma histamine concentrations,incidence of histaminemia,degree of cutaneous color,and incidence of hypotension and tachycardia were significantly decreased (P＜0.05),and no significant change was found in the peak airway pressure,Steward recovery scores and Ramsay sedation scores in group CF (P＞0.05).Conclusion For atracurium-induced release of histamine in the patients undergoing surgery under general anesthesia,clemastine fumarate 2 mg injected intramuscularly before operation can not only antagonize histamine at H1 level,but also reduce histamine release,and exerts no influence on recovery from anesthesia and produces good antihistamine efficacy.

Application of antihistamines in special populations / 中华皮肤科杂志

Antihistamines,a group of drugs most commonly used for the treatment of allergic diseases in dermatology,exert favorable efficacy and are well tolerated in most people.Due to their wide application,the safety of medication is particularly important.When they are used in some special populations with allergic diseases,such as children,pregnant and lactating women,the elderly and people with hepatic or renal insufficiency,their pharmacodynamics,metabolic characteristics and interactions with other drugs should be fully considered,and profits of medication and potential adverse effects should be well weighed before choosing relatively safe antihistamines.In addition,decreasing the routine dose or prolonging intervals between the administration of antihistamines may also be attempted to achieve maximum safety.

Efficacy of fexofenadine hydrochloride tablets at tapering doses for the treatment of chronic spontaneous ;urticaria:a clinical observation / 中华皮肤科杂志

Objective To evaluate the efficacy of fexofenadine hydrochloride tablets at tapering doses for the treatment of chronic spontaneous urticaria. Methods After receiving evaluation of medical history and undergoing autologous serum skin test (ASST), 80 patients with chronic spontaneous urticaria were randomly divided into two groups:conventional dose group administrating fexofenadine hydrochloride tablets 120 mg/d for 12 consecutive weeks, tapering dose group administrating fexofenadine hydrochloride tablets 120 mg/d for the first 4 weeks followed by dose tapering of fexofenadine hydrochloride tablets by 30 mg at the 5th and 9th weeks. The urticaria activity score(UAS) and dermatology life quality index(DLQI)were evaluated before the treatment(baseline)as well as after 4?, 8?and 12?week treatment, and the total dose of fexofenadine hydrochloride was calculated. Results A total of 76 patients completed the 12?week treatment, including 37 patients in the conventional dose group and 39 patients in the tapering dose group. After 4?, 8?and 12?week treatment, a significant decrease was observed in the UAS in the conventional dose group(0.64 ± 0.82, 0.37 ± 0.68 and 0.27 ± 0.56 vs. 4.08 ± 0.79, all P0.05). After 8?and 12?week treatment, symptoms were controlled in 71.79%(28/39)and 82.05%(32/39)of patients in the tapering dose group, respectively, with the total dose of fexofenadine hydrochloride being significantly lower in the tapering dose group than in the conventional dose group (both P<0.001). Conclusion After 4- 8 weeks of treatment with fexofenadine hydrochloride, the tapering dose regimen and conventional dose regimen show similar clinical efficacy in patients with chronic spontaneous urticaria.

Approaches to the diagnosis and management of chronic urticaria in children / 소아과

Most guidelines for chronic urticaria (CU) in infants and children are based on limited pediatric evidence. Current evidence used to guide treatment in children is extrapolated from data focusing on older age groups. CU in children is a different and complex condition than that in adults. Furthermore, there is little published information regarding urticaria in Korean children. The aim of the present article is to review recent research on chronic childhood urticaria and improve the current understanding of its pathogenesis and management. The classification and definition of urticaria in adults also applies to children. CU is defined as a daily occurrence of spontaneous wheals, angioedema, or both for >6 weeks. The precise pathophysiology of CU is unknown and the rates of successful identification of a cause in children with CU vary from 20%-50%. There is no established laboratory test to evaluate the presence of urticaria. The natural course of childhood CU is undetermined, with limited reports discussing long-term outcomes. Second-generation H1 antihistamines are the cornerstone of management, while limited therapeutic drugs are available for adults.

Gynecomastia induced by H1-antihistamine (ebastine) in a patient with idiopathic anaphylaxis

H1-antihistamine is generally a well-tolerated and safe drug. However, in resemblance with all other drugs, H1-antihistamines can also prompt adverse drug reactions (ADRs). We recently encountered the very unusual ADR of H1-antihistamine-induced gynecomastia. A 21-year-old man with idiopathic anaphylaxis was treated with ebastine (Ebastel), a second-generation H1-antihistamine, for the prevention of anaphylaxis. Three months later, the patient remained well without anaphylaxis, but had newly developed gynecomastia. Because anaphylaxis recurred after the cessation of H1-antihistamine, the preventive medication was changed to omalizumab. A few months later, his gynecomastia had entirely disappeared. Physicians should be aware of this exceptional ADR of H1-antihistamine.

Gabapentin in treatment for pruritus and insomnia among patients with hemodialysis / 中华全科医师杂志

This paper aimed to study clinical effectiveness of gabapentin in the treatment for pruritus and insomnia among patients with hemodialysis. Eighty patients with severe pruritus and insomnia during regular hemedialysis in Jiaozhou People's Hospital, Jiangsu were randomly divided into two groups with 40 patients each. Gahapentin 0. 1 g were given each patient every night for 4 weeks in one group and a modified-re]ease capsule of 8 mg chiorphenamine maleate was given each patient daffy for 4 weeks in the other group. Effectiveness of treatment was evaluated by improvement of itching symptoms and Pittsburgh Sleep Quality Index (PSQI) scores for insomnia in the patients. Itching improvement was observed in 85%(34/40) of the patients and PSQI scores obviously lowered in them four weeks after gabapentin treatment.However, itching improvement was observed only in 42% ( 17/40 ) of the patients and little change was observed in PSQI scores in them four weeks after chlorphenamine treatment It suggests that gabapentin can significantly improve quality of sleeping and itching symptoms in patients with hemodialysis and it is worthy popularizing in those with it.

Fexofenadine-Induced Urticaria

Fexofenadine (Allegra(R) 180) is a second-generation antihistamine. It is widely used as anti-allergic drug, which suppresses various allergic reactions mediated by histamines. A few cases of H1-antihistamine-induced urticaria have been reported. Herein, we report a rare case of fexofenadine-induced urticaria which was confirmed by a prick test, oral provocation test, and flow cytometry assisted-basophil activation test.

Revisão sobre a efícacia e segurança dos anti-histamínicos de primeira e segunda geração / Revision on efficacy and safety of antihistamines of first and second generation

Objetivo: Revisar a eficácia e segurança dos principais anti-histamínicos de primeira e segunda geração. Os anti-histamínicos correspondem a um grupo extenso de medicamentos que vêm apresentando grandes avanços no conhecimento de suas ações e estão entre os agentes mais utilizados na prática clínica em diversas doenças alérgicas. Método: Levantamento bibliográfico nos bancos de dados PubMed, Medline, LILACS, SCIELO e capítulos de livros nos últimos 10 anos, sendo incluídos artigos históricos. Resultados: Nessa revisão são destacadas as principais características da histamina, as diferenças entre os receptores de histamina, o desenvolvimento dos anti-histamínicos de primeira e segunda geração, sua classificação e os principais efeitos colaterais de cada grupo de anti-histamínicos. Conclusão: A presente revisão não pretende esgotar o assunto sobre eficácia e segurança dos anti-histamínicos, mas destaca a falta de estudos bem conduzidos sobre eficácia dos anti-histamínicos de primeira geração e o número crescente de metanálises sobre farmacodinâmica, potência, eficácia e segurança dos anti-histamínicos de segunda geração.

Objective: To review the efficacy and safety of the main antihistamines of first and second generation. The antihistamines represent an extensive group of drugs that are showing great advances in knowledge of their actions and are among the most common agents used in clinical practice in various allergic diseases. Method: Searches in PubMed, Medline, LILACS, SCIELO database and book chapters in the last 10 years, including historic articles. Results: This review highlights the main features of histamine, the differences between histamine receptors, development of first and second generation antihistamines, their classification, and the main side effects of each group of antihistamines. Conclusion: The present review is not intended to exhaust the subject on efficacy and safety of antihistamine, but it highlights the lack of well conducted studies of the efficacy of first-generation antihistamine and the rising number of meta-analysis of pharmacodynamics, potency, efficacy and safety of second-generation antihistamines.

Histamina, receptores de histamina e anti-histamínicos: novos conceitos / Histamine, histamine receptors and antihistamines: new concepts

As drogas com ação anti-histamínica estão entre as medicações mais comumente prescritas na prática dermatológica diária, tanto em adultos como em crianças. Este artigo aborda os novos conceitos da função dos receptores de histamina (receptores H1) e discute os efeitos anti-inflamatórios dessas drogas. A segunda geração de anti-histamínicos difere da primeira geração devido a sua elevada especificidade e afinidade pelos receptores H1 periféricos e devido a seu menor efeito no sistema nervoso central, tendo como resultado menores efeitos sedativos. Embora a eficácia dos diferentes anti-histamínicos H1 (anti-H1) no tratamento de doentes alérgicos seja similar, mesmo quando se comparam anti-H1 de primeira e de segunda geração, eles são muito diferentes em termos de estrutura química, farmacologia e propriedades tóxicas. Consequentemente o conhecimento de suas características farmacocinéticas e farmacodinâmicas é importante para a melhor prática médica, especialmente em gestantes, crianças, idosos e doentes com comorbidades.

Drugs with antihistamine action are the most commonly prescribed medication in daily dermatologic practice, both to adults and children. This article addresses new concepts of the role of histamine receptors (H1 receptors) and discusses the anti-inflammatory effects of these drugs. Second generation antihistamines differs from first generation because of their high specificity and affinity for peripheral H1-receptors. Second generation antihistamines are also less likely to produce sedation because they have less effect on the central nervous system. Although the efficacy of the various H1-antihistamines in the treatment of allergic patients is similar, even when comparing first- and second-generation drugs, these drugs are still very different in terms of their chemical structure, pharmacology and toxic properties. Consequently, knowledge of their pharmacokinetic and pharmacodynamic characteristics is essential for a better medical care, especially that offered to pregnant women, children, the elderly, and patients with comorbidities.

Urticária aquagênica familiar: relato de dois casos e revisão da literatura / Familial aquagenic urticaria: report of two cases and literature review

Urticária aquagênica é forma rara de urticária física caracterizada por aparecimento de urticas após o contato com água, independente da temperatura. Há poucos casos descritos de urticária aquagênica e, destes, somente cinco da forma familiar. Apresentamos o primeiro relato de urticária aquagênica familiar no Brasil, acometendo mãe e filha. Ambas apresentavam urticas, principalmente após banho de chuveiro, independentemente da temperatura da água. A mãe referia ter o quadro há quatro anos, e a filha, desde o nascimento. Para diagnóstico, foram realizados testes de provocação com água, com aparecimento de lesões em ambas, e testes com dermografômetro, com cubo de gelo envolvido em plástico e de provocação para urticária colinérgica, sem o aparecimento de lesões, excluindo assim outras formas de urticária física.

Aquagenic urticaria is a rare form of physical urticaria, characterized by pruritic wheals that appear following contact with water, independently of its temperature. There are few reports of cases of aquagenic urticaria, and only five include the familial form. We present the first case of familial aquagenic urticaria in Brazil (mother and daughter). Both patients presented wheals following contact with water, especially when showering, regardless of its temperature. The mother reported onset of urticaria four years before and the daughter presented wheals since birth. For diagnostic purposes, they were submitted to a challenge test with water, and both subjects presented wheals, as well as to tests using ice cubes in plastic bag with dermographometer and challenge tests for cholinergic urticaria, with no appearance of lesions, excluding other forms of physical urticaria.