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.

Histamine Excites Rat GABAergic Ventral Pallidum Neurons via Co-activation of H1 and H2 Receptors / 神经科学通报·英文版

The ventral pallidum (VP) is a crucial component of the limbic loop of the basal ganglia and participates in the regulation of reward, motivation, and emotion. Although the VP receives afferent inputs from the central histaminergic system, little is known about the effect of histamine on the VP and the underlying receptor mechanism. Here, we showed that histamine, a hypothalamic-derived neuromodulator, directly depolarized and excited the GABAergic VP neurons which comprise a major cell type in the VP and are responsible for encoding cues of incentive salience and reward hedonics. Both postsynaptic histamine H1 and H2 receptors were found to be expressed in the GABAergic VP neurons and co-mediate the excitatory effect of histamine. These results suggested that the central histaminergic system may actively participate in VP-mediated motivational and emotional behaviors via direct modulation of the GABAergic VP neurons. Our findings also have implications for the role of histamine and the central histaminergic system in psychiatric disorders.

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.

The effects of electrical stimulation on the expression of H1 receptor in the prefrontal cortex of brain injured, comatose rats / 中华物理医学与康复杂志

Objective To investigate the expression of H1 protein in the prefrontal cortex of comatose rats which have suffered traumatic brain injury (TBI) after electrical stimulation of the median nerve (MNS).Methods Seventy-two Sprague-Dawley rats (weighing 250 to 300 g) were randomly divided into a stimulated group (MNS+ TBI),an antagonist group (MNS+TBI+OXR1 antagonist),a model group (TBI) and a control group,with 18 rats in each group.Traumatic brain injury was modeled in all of the rats except those of the control group.After the modeling,the stimulated group was given MNS,the antagonist group was provided with MNS and an OXR1 injection,and the model group was given MNS with a current intensity of 0.One hour after the experiment,the consciousness of each rat was evaluated using a double-blind method.Animals were sacrificed at 6,12 and 24 hours after the intervention and brain tissue was removed.H1 protein expression was examined using immunohistochemistry.Results One hour after the experiment,significant differences were observed in the consciousness of the 4 groups,with the 18 rats of the control group on consciousness level one.Thirteen rats in the stimulated group exhibited a righting reflex,compared with 9 in the antagonist group and 5 in the model group.Immunohistochemistry showed that H1 expression was strongest in the stimulated group,followed by the antagonist,control and model groups.The H1 expression was highest at 24 hours after the experiment,followed by that at 6 h and 12 h,but those differences were not statistically significant.Conclusion Median nerve electrical stimulation might modulate wakefulness after traumatic brain injury by promoting H1 expression via orexin-A in the prefrontal contex.

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.

Pressor Effect of Intracerebroventricular Diphenhydramine and Ranitidine in Rabbits

This study was undertaken to observe the effects of centrally administred antihistamines on the blood pressure. Diphenhydramine(DPH), a H1-receptor antagonist, and ranitidine(RAN), a H2-receptor antagonist were administered intracerebroventricularly(icv) on urethane-anesthetized rabbits. 1) Both DPH and RAN administered intraccebroventricularly increased blood pressure, however the intravenous(iv) adminstration of them did not affect blood pressure. The pressor response to icv DPH was dose-dependent, but that to icv RAN was not. 2) The pressor response to icv DPH(1mg) was either markedly attenuated or reversed to depressor response by the pretreatment with icv phentolamine(250,500ug), and iv chlorisondamine(0.1, 1mg/Kg) and iv phenoxybenzamine(1mg/Kg). In cord-sectioned rabbtis, icv RAN) 1mg) did not produce pressor response. 3) The pressor responsr to icv RAN(1mg) was not affected by the pretreatment with icv phentolamine(500ug), iv chlorisondamin(1mg/Kg) and iv phenoxybenzamine(1mg/Kg), and iv phenoxybenzamine(1mg/Kg). RAN also producted pressor response in cordsectioned rabbits. These results suggest that the pressor response to icv DPH is elecited by increasing peripheral sympathetic tone via the stimulation of central alpha-adrenoreceptors and the pressor response to icv RAN is produced by releasing some humoral facotr which can increase blood pressure.

Expression of histamine H_1 receptor gene in hepatocarcinoma of rats induced by dimethylamino-azobenzene / 中国药理学通报

AIM To study the mRNA expression of histamine H_1 receptor in hepatocarcinoma of rats. METHODS Dimethylamino-azobenzene (DAB) was used to induce hepatocarcinoma in rats. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was adopted to analyse the relative expression of histamine H_1 receptor. And the base sequence of its PCR product was detected. RESULTS The relative mRNA expression of histamine H_1 receptor was significantly decreased in hepatic carcinoma tissue, compared with that part far from cancer and control group (P

Study advances of cytochome P450 sensitive to antihistamine drugs / 中国药理学通报

HP450 has thecharacteristic of cytochrome P450 and sensitivity to antihistmine drugs.With distinct raiiable regularity in the diverse disease modes of the rat,and some relativity to the development of liver disease,the expression and transcription of the HP450s gene have all changed in the course of the liver cancer. HP450 is possibly regarded as a new index of diagnosing liver cancer and a new target site of preventing and treating liver cancer