Antihistamine therapy in allergic rhinitis

Evaluation of Urtica dioica Phytochemicals against Therapeutic Targets of Allergic Rhinitis Using Computational Studies

Allergic rhinitis (AR) is a prevalent inflammatory condition affecting millions globally, with current treatments often associated with significant side effects. To seek safer and more effective alternatives, natural sources like Urtica dioica (UD) are being explored. However, UD's mechanism of action remains unknown. Therefore, to elucidate it, we conducted an in silico evaluation of UD phytochemicals' effects on known therapeutic targets of allergic rhinitis: histamine receptor 1 (HR1), neurokinin 1 receptor (NK1R), cysteinyl leukotriene receptor 1 (CLR1), chemoattractant receptor-homologous molecule expressed on type 2 helper T cells (CRTH2), and bradykinin receptor type 2 (BK2R). The docking analysis identified amentoflavone, alpha-tocotrienol, neoxanthin, and isorhamnetin 3-O-rutinoside as possessing a high affinity for all the receptors. Subsequently, molecular dynamics (MD) simulations were used to analyze the key interactions; the free energy of binding was calculated through Generalized Born and Surface Area Solvation (MMGBSA), and the conformational changes were evaluated. Alpha-tocotrienol exhibited a high affinity while also inducing positive conformational changes across all targets. Amentoflavone primarily affected CRTH2, neoxanthin targeted NK1R, CRTH2, and BK2R, and isorhamnetin-3-O-rutinoside acted on NK1R. These findings suggest UD's potential to treat AR symptoms by inhibiting these targets. Notably, alpha-tocotrienol emerges as a promising multi-target inhibitor. Further in vivo and in vitro studies are needed for validation.

Electrochemical HPLC Determination of Piperazine Antihistamine Drugs Employing a Spark-Generated Nickel Oxide Nanoparticle-Modified Carbon Fiber Microelectrode

In this work, we demonstrate a sensitive high-performance liquid chromatography (HPLC) method for the determination of piperazine antihistamine drugs employing innovative electrochemical detection based on a spark-generated nickel oxide nanoparticle-modified carbon fiber microelectrode built into a miniaturized electrochemical detector. The direct carbon fiber-to-nickel plate electrode spark discharge, carried at 0.8 kV DC, with the nickel electrode connected to the negative pole of the high-voltage power supply, provides extremely fast (1 s) in situ tailoring of the carbon fiber microelectrode surface by nickel oxide nanoparticles. It has been found that nickel oxide nanoparticles exhibit an electrocatalytic effect toward the piperazine moiety electrooxidation process, as confirmed by voltammetric experiments, revealing the shift in the peak potential from 1.25 to 1.09 V versus Ag/AgCl. Cetirizine, cyclizine, chlorcyclizine, flunarizine, meclizine, and buclizine were selected as sample piperazine antihistamine drugs, while diclofenac served as an internal standard. The isocratic reversed-phase separation of the above set was achieved within 15 min using an ARION-CN 3 μm column with a binary mobile phase consisting of 50 mM phosphate buffer (pH 3) and methanol (45/55, v/v). The limits of detection (LOD) were within the range of 3.8-120 nM (for cyclizine and buclizine) at E = +1500 mV (vs Ag/AgCl), while the response was linear within the concentration range measured up to 5 μmol L-1. The method was successfully applied to the determination of piperazine antihistamine drugs in spiked plasma samples.

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

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.

Shufeng Jiedu capsule ameliorates olfactory dysfunction via the AMPK/mTOR autophagy pathway in a mouse model of allergic rhinitis

BACKGROUND

Shufeng Jiedu capsule (SFJDC) has been widely used as a conventional Chinese pharmaceutical agent for various upper respiratory infections, including acute lung injury, acute respiratory distress syndrome and allergic rhinitis (AR). However, its mechanism in AR remains unclear.

PURPOSE

The present study aimed to decipher the antiallergic inflammatory effect of SFJDC in an AR model with olfactory dysfunction. Specifically, we wanted to explore whether SFJDC can improve the olfactory abnormality in AR mice and reduce the levels of inflammatory factors in the olfactory epithelium (OE) and olfactory bulb (OB).

METHODS

To address the above issues, we constructed an AR model using C57BL/6 mice, which were sensitised and challenged with ovalbumin (OVA) by intraperitoneal injection. SFJDC (0.045 or 0.18 g/kg) was delivered by gavage administration 1 h prior to the intraperitoneal injection of OVA. The control mice received saline alone. Then, the animals were assessed according to the presence of nasal symptoms and nasal inflammation, and a buried food test was used to evaluate olfactory function. The levels of proteins involved in the AMPK/mTOR autophagy pathway in the OE and OB were investigated by western blotting and fluorescence staining.

RESULTS

After OVA induction of AR and drug administration, we found that SFJDC significantly ameliorated the nasal symptoms and allergic inflammatory reaction of the nasal mucosa superior to cetirizine. A behavioural test indicated that the mice with AR had olfactory dysfunction, and SFJDC can ameliorate this behavior deficiency. Meanwhile, SFJDC clearly reduced the neuroinflammation level in OE tissue. In addition, SFJDC increased p-mTOR and decreased p-AMPK, beclin1, LC3 and cleaved caspase-3 levels in the OE.

CONCLUSIONS

In addition to antibacterial and antiviral activities, SFJDC has marked anti-inflammatory effects in AR mice. Its mechanism of action in the nasal cavity involves inhibition of upregulated anti-inflammatory cytokines, modulation of autophagy and apoptosis levels and regulation of autophagy through the AMPK/mTOR pathway in the OE tissue of AR mice. Hence, SFJDC is a promising drug for AR, and clinical trials should further validate the therapeutic impact of SFJDC on AR with olfactory dysfunction.

Enantiomeric separation of oxomemazine in rabbit plasma by ultra-fast LC and application in a stereoselective pharmacokinetic study

Aim: Ultra-fast LC was used to establish a new bioanalytical method for enantiomeric separation of oxomemazine. Methods: The proposed study was carried out using the ultra-fast LC technique with an amylose chiral column. The bioanalytical approach was used in rabbit plasma following US FDA regulations and then extended to oxomemazine enantiomeric separation using metronidazole as the internal standard. Results: The retention times of (R)-oxomemazine, (S)-oxomemazine and the internal standard were found to be 9.511, 10.712 and 6.503 min, respectively. Within-run and between-run precision (percent relative standard deviation) was found to be in the range of 0.018-0.102% for (R)-oxomemazine and 0.028-0.675% for (S)-oxomemazine, whereas accuracy (%) was found to be in the range of 95.971-99.720% for (R)-oxomemazine and 97.199-103.921% for (S)-oxomemazine. Conclusion: The findings revealed that stereospecific distribution of oxomemazine enantiomers does not change significantly.

Higenamine alleviates allergic rhinitis by activating AKT1 and suppressing the EGFR/JAK2/c-JUN signaling

BACKGROUND

Allergic rhinitis (AR) is an inflammatory, immunoglobulin E (IgE)-mediated disease characterized by the typical symptoms of sneezing, rhinorrhea, nasal itching, and congestion. Higenamine (HG) is a plant-based alkaloid, possesses a wide range of activities, including vascular and tracheal relaxation, antioxidative, antiapoptotic, anti-inflammatory, and immunomodulatory activities. So far, the effect and the underlying mechanism of HG on AR have not been studied.

HYPOTHESIS/PURPOSE

The purpose of this study was to evaluate the effects of HG on AR and investigate its underlying mechanism.

METHODS

The effects of HG on AR were evaluated in an ovalbumin-induced AR mouse model. Network pharmacology-based methods such as target prediction, protein-protein interaction (PPI) network analysis, pathway analysis, and molecular docking were used to identify the likely HG targets. Finally, we validated the mechanism of action of HG through its effects on these targets in human nasal epithelial cells (HNEpCs).

RESULTS

Oral administration of 30, 60, and 120 mg/kg HG significantly alleviated rubbing and sneezing in AR mice and attenuated histopathological changes in the lung and nasal tissues. Additionally, HG reduced the levels of IgE, histamine, and IL-4 in the serum of AR mice, and regulated imbalance in Th1/Th2 cells. Using network pharmacology-based methods, we identified 29 HG targets related to AR. These targets are mainly involved in the PD-L1, relaxin, estrogen, HIF-1, Th1 and Th2 cell differentiation, T cell receptor, and the Th17 cell differentiation signaling pathways. Molecular docking showed that HG may well be suited to the receptor binding pockets of key target AKT1, EGFR, c-Jun, NOS2, and JAK2. In HNEpCs, HG inhibited the histamine-induced mRNA expression and secretion of interleukin (IL)-6, and IL-8, as well as the expression of MUC5AC and the phosphorylation of NF-κB. Moreover, HG affected the changes of AKT1, EGFR, c-Jun, iNOS, and JAK2 induced by histamine.

CONCLUSION

Overall, our results suggest that HG may alleviate AR by activating AKT1 and suppressing the EGFR/JAK2/c-JUN signaling. HG, therefore, has great potential as a therapeutic agent for the treatment of AR.

Assessing the effect of prolonged use of desloratadine on adipose Brillouin shift and composition in rats

Antihistamines, which are commonly used to treat allergic reactions, are known for their side effects, which contribute to weight gain. It is hypothesized that simultaneous Brillouin elastography and Raman spectroscopy can be used to detect changes in adipose tissue associated with a prolonged intake of desloratadine, a commonly used second generation antihistamine. White and brown adipose tissue samples were excised from adult rats following 16 weeks of daily administration of desloratadine. It was found that the prolonged intake of desloratadine leads to an increase in Brillouin shift in both adipose tissue types. Raman spectra indicate that antihistamine use reduces protein-to-lipid ratio in brown adipose tissue but not white adipose tissue, indicating the effect on adipose tissue is location-dependent.

Emedastine During Pregnancy and Lactation: Emedastine Levels in Maternal Serum, Cord Blood, Breast Milk, and Neonatal Serum

Background: Emedastine difumarate is a second-generation antihistamine that is more effective for nasal congestion than first-generation antihistamines. The oral form of emedastine is used for the treatment of allergic rhinitis (AR). However, data characterizing emedastine transfer across the placenta and excretion into breast milk are limited. In this case report, we assessed emedastine concentrations in maternal and neonatal blood, cord blood, and breast milk. Materials and Methods: After the patient provided informed consent, emedastine concentrations in maternal serum, breast milk, cord blood, and neonatal serum were measured while the mother was taking oral emedastine 2 mg once daily. Case Report: A 39-year-old woman with AR received emedastine during pregnancy and lactation. Her female infant was born at 37 weeks of gestation with a birth weight of 2,820 g. Emedastine concentrations in maternal serum at 11.5 and 19.0 hours after maternal dosing were 0.39 and 0.22 ng/mL, respectively. The emedastine concentration in cord blood (19.6 hours after maternal dosing) was 0.18 ng/mL. At 24 hours after delivery (44 hours after maternal dosing), emedastine was under the lower limit of quantification (<0.05 ng/mL) in the infant's serum. Emedastine concentrations in breast milk ranged from 0.06 to 0.44 ng/mL. Calculated infant doses through breast milk were much lower than the clinical dose of emedastine. The infant had normal developmental progress and no detectable drug-related adverse effects. Conclusions: Rates of emedastine transfer into placenta and breast milk were low. Further study is required to assess the safety of emedastine in fetuses and breastfed infants.

Spinal sensory and motor blockade by intrathecal doxylamine and triprolidine in rats

OBJECTIVES

The aim of this experiment was mainly to examine the effects of intrathecally injected doxylamine and triprolidine, two antihistamine drugs spinal motor and sensory functions.

METHODS

After intrathecally injecting the rats with five different doses, the dose-response curves of spinal sensory and motor block with doxylamine and triprolidine were constructed. In comparison with the local anaesthetic mepivacaine, the quality and duration of spinal anaesthesia with doxylamine or triprolidine were conducted.

KEY FINDINGS

Doxylamine, mepivacaine and triprolidine elicited spinal motor and sensory (nociception and proprioception) blockades in a dose-dependent fashion. On the ED₅₀ (50% effective dose) basis, the rank order of drug potency was triprolidine > mepivacaine > doxylamine (P < 0.05) at provoking spinal motor, proprioceptive and nociceptive blockades. On the equianaesthetic doses (ED₂₅ , ED₅₀ and ED₇₅ ), the duration of spinal anaesthesia with doxylamine was longer (P < 0.01) than that with mepivacaine or triprolidine. Moreover, doxylamine or triprolidine displayed greater potency (ED₅₀ ) (P < 0.05) and duration (P < 0.05) of sensory block over motor block.

CONCLUSIONS

Doxylamine or triprolidine produces a dose-dependent effect of spinal motor and sensory block. Triprolidine with a better nociception-selective action over motor block has a better potency than mepivacaine or doxylamine. Doxylamine and triprolidine produce longer durations than mepivacaine.

Subcutaneous infiltration of doxylamine on cutaneous analgesia in rats

BACKGROUND

We aimed to evaluate the effect of doxylamine, a first generation antihistamine, as a local analgesic agent by comparing its effect to bupivacaine.

METHODS

After blocking the cutaneous trunci muscle reflex (CTMR) by subcutaneous injection of doxylamine, we assessed doxylamine's cutaneous analgesic effect in rats. The dose-related effect and duration of doxylamine on infiltrative cutaneous analgesia were compared with that of bupivacaine.

RESULTS

We demonstrated that doxylamine, as well as the local anesthetic bupivacaine produced the cutaneous analgesic effects in a dose-related fashion. At the equipotent dose (50% effective doses (ED₅₀)), the relative potency was bupivacaine (0.41 (0.36-0.48) mmol)> doxylamine (7.39 (6.91-7.91)mmol) (p<0.01). On an equipotent basis (ED₂₅, ED₅₀ and ED₇₅), subcutaneous doxylamine resulted in greater duration of action (p<0.01) than bupivacaine at producing cutaneous analgesia.

CONCLUSIONS

The result of this experiment indicated that doxylamine has the local anesthetic property less potent than bupivacaine, but its nociceptive block duration is longer than that of bupivacaine at an equianalgesic dose.

Identification of selective 8-(piperidin-4-yloxy)quinoline sulfone and sulfonamide histamine H1 receptor antagonists for use in allergic rhinitis

A series of potent, selective and long-acting quinoline-based sulfonamide human H₁ histamine receptor antagonists, designed for once-daily intranasal administration for the treatment of rhinitis were developed. Sulfonamide 33b had a slightly lower affinity for the H₁ receptor than azelastine, had low oral bioavailability in the rat and dog, and was turned over to five major metabolites. Furthermore, 33b had longer duration of action than azelastine in guinea pigs, lower rat brain-penetration, and did not cause time dependent inhibition of CYP2D6 or CYP3A4. The clinical dose in humans is expected to be low (approximately 0.5mg per day) based on the clinical dose used for azelastine and a comparison of efficacy data from animal models for 33b and azelastine.

Design of Phthalazinone Amide Histamine H1 Receptor Antagonists for Use in Rhinitis

The synthesis of potent amide-containing phthalazinone H₁ histamine receptor antagonists is described. Three analogues 3e, 3g, and 9g were equipotent with azelastine and were longer-acting in vitro. Amide 3g had low oral bioavailability, low brain-penetration, high metabolic clearance, and long duration of action in vivo, and it was suitable for once-daily dosing intranasally, with a predicted dose for humans of approximately 0.5 mg per day.

Tonggyu-tang, a traditional Korean medicine, suppresses pro-inflammatory cytokine production through inhibition of MAPK and NF-κB activation in human mast cells and keratinocytes

Background

Allergic diseases including allergic rhinitis, asthma, and atopic dermatitis are increasing worldwide. Common medications used to treat these inflammatory disorders are anti-histamines and corticosteroids, but they have their own limitations such as short duration and severe side effects. Thus, interest in complementary and alternative medicine is continually growing. Here, we investigate the anti-inflammatory mechanisms of Tonggyu-tang (TGT), a traditional Korean medicine that has been used to treat patients with allergic nasal disorders.

Methods

We measured mRNA expressions and production of pro-inflammatory cytokines such as interleukin (IL)-4, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α) by RT-PCR and ELISA assays in HMC-1 (human mast cell line-1) and HaCaT cells, immortalized human keratinocytes. Moreover, we evaluated the effect of TGT on two major inflammation-related pathways, mitogen activated protein kinase (MAPK) and NF-κB signaling pathway in these two cells.

Results

Our results revealed that that TGT significantly reduced the expression and production of inflammatory cytokines such as IL-4, IL-6, IL-8, and TNF-α in the agonist-treated HMC-1 and HaCaT cells. We also found that TGT suppressed MAPK signaling pathway including extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38), and c-Jun N-terminal kinase (JNK) as well as NF-κB pathway, which are known to regulate inflammatory cytokine expression.

Conclusion

Taken together, our results demonstrate that TGT inhibits expression of pro-inflammatory cytokines by suppressing MAPK and NF-kB pathway in both mast cells and keratinocytes, suggesting the potential use of TGT in treating allergic inflammatory diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1704-5) contains supplementary material, which is available to authorized users.

A Network Meta-analysis of Randomized Controlled Trials Focusing on Different Allergic Rhinitis Medications

This study is aimed to investigate the effectiveness of 4 allergic rhinitis (AR) drugs (loratadine, cetirizine, montelukast, and desloratadine) in reducing functional problems in patients, as indicated by rhinoconjunctivitis quality of life questionnaire scores. After an exhaustive search of electronic databases containing published scientific literature, high-quality randomized controlled trials relevant to our study were selected based on a stringent predefined inclusion and exclusion criteria. Statistical analyses were conducted using STATA 12.0 and comprehensive meta-analysis (CMA 2.0) software. The literature search broadly identified 386 studies, and after a multistep screening and elimination process, a total of 13 randomized controlled trials contributed to this network meta-analysis. These 13 high-quality studies contained a combined total of 6867 patients with AR on 4 different medications. The results of network meta-analysis revealed that, compared with placebo, all 4 mediations treated AR effectively [cetirizine: mean: -0.62, 95% confidence intervals (95% CI) = -0.90 to -0.34, P < 0.001; loratadine: mean: -0.32, 95% CI = -0.55 to -0.097, P = 0.005; montelukast: mean: -0.28, 95% CI = -0.54 to -0.023, P = 0.033; desloratadine: mean: -0.39, 95% CI = -0.60 to -0.18, P < 0.001]. A comparison of surface under the cumulative ranking curve values of these 4 interventions clearly showed that cetirizine is the most optimal medication for AR treatment. In conclusion, this network meta-analysis provides the first evidence that cetirizine is the most efficacious treatment for AR compared with loratadine, montelukast, and desloratadine, significantly reducing the functional problems in patients with AR.

Montelukast in the treatment of perennial allergic rhinitis in paediatric Japanese patients; an open-label clinical trial

Background: This study was conducted to evaluate the safety and tolerability, and population pharmacokinetics (PPK) of montelukast as well as efficacy in the treatment of perennial allergic rhinitis (PAR) in paediatric Japanese patients aged between 1 and 15 years. Methods: In this multi-centre, open-label trial, 87 paediatric Japanese patients with PAR received montelukast 4 mg oral granules (OG) for 4 weeks (1-5-year-olds, N = 15), 4 mg OG for 12 weeks (1-5-year-olds, N = 36), 5 mg chewable tablets (CT) for 12 weeks (6-9-year-olds, N = 18), or 5 mg CT for12 weeks (10-15-year-olds, N = 18). Clinical exams and laboratory assessments were conducted at study visits, and adverse events (AE) were monitored throughout the study up to 14 days after the last visit. Population pharmacokinetic approach was used to estimate AUC0-∞, Cmax, Tmax and apparent elimination half-life in each age group. Efficacy was assessed based on global evaluations by the subject's caregiver. Results: There were no serious AEs and one discontinuation due to an AE. The most common AEs in any of the treatment groups were nasopharyngitis, pharyngitis, and acute sinusitis. Montelukast exposure (AUC0-∞) was similar in the 1-5-year-old group and the 6-9-year-old group, but 19% lower in the 10-15-year-old group. Among all patients, the total proportion of patients whose global evaluation was "very much better" was 5.7% (week 2), 11.5% (week 4), and 16.9% (week 12) reflecting improvement in symptoms over time. Conclusion: Montelukast was generally well tolerated in Japanese children with PAR. AUC0-∞was similar in 1-5 and 6-9-year-olds, while a lower exposure was observed in the 10-15-year-old group likely due to differences in bodyweight. The exposure in Japanese paediatric patients was generally consistent with that in non-Japanese paediatric and adult patients. As assessed by the patients' caregivers, montelukast also demonstrated symptomatic improvement based on global evaluations of PAR.

Allergic Rhinitis and Chronic Daily Headaches: Is There a Link?

Allergic rhinitis and migraine remain on the list of the most common diseases affecting adults. Migraines and headaches due to allergic rhinitis are easily confused because the symptoms of both conditions often overlap. Both may occur with sinus headache, nasal congestion, and lacrimation and may worsen with weather changes and exposure to allergens. No precise clinical definition exists for what constitutes a sinus headache, which has always been a diagnostic dilemma. Contrary to popular belief, headache is not a typical symptom of rhinitis. Some studies have shown that up to 90 % of sinus headaches are actually migraines. Nevertheless, patients with self-diagnosed sinus headache self-treat or are treated by primary care physicians and/or otolaryngologists with medications for rhinosinusitis, ignoring the neurogenic causes of the symptoms when most of these patients fulfill diagnostic criteria for chronic migraine. Chronic migraine affects 2 % of the general population and has a significant socioeconomic impact on society, incurring health care costs and diminishing quality of life; therefore, the proper diagnosis and treatment of these headache patients should be a priority.

Enantioseparation of Six Antihistamines with Immobilized Cellulose Chiral Stationary Phase by HPLC

A stereoselective high performance liquid chromatography method has been developed for the chiral separation of the enantiomers of six antihistamines, doxylamine, carbinoxamine, dioxopromethazine, oxomemazine, cetirizine and hydroxyzine. The effects of mobile phase additive, column temperature and flow rate on the retention time and resolution were studied. Enantiomeric separation of cetirizine, doxylamine and hydroxyzine were achieved on cellulose tris-(3,5-dichlorophenylcarbamate) immobilized on silica gel chiral stationary phase known as Chiralpak IC (RS = 3.74, RS = 1.85 and RS = 1.74, respectively).

Update on rupatadine in the management of allergic disorders

In a review of rupatadine published in 2008, the primary focus was on its role as an antihistamine, with a thorough evaluation of its pharmacology and interaction with histamine H1 -receptors. At the time, however, evidence was already emerging of a broader mechanism of action for rupatadine involving other mediators implicated in the inflammatory cascade. Over the past few years, the role of platelet-activating factor (PAF) as a potent mediator involved in the hypersensitivity-type allergic reaction has gained greater recognition. Rupatadine has dual affinity for histamine H1 -receptors and PAF receptors. In view of the Allergic Rhinitis and its Impact on Asthma group's call for oral antihistamines to exhibit additive anti-allergic/anti-inflammatory properties, further exploration of rupatadine's anti-PAF effects was a logical step forward. New studies have demonstrated that rupatadine inhibits PAF effects in nasal airways and produces a greater reduction in nasal symptoms than levocetirizine. A meta-analysis involving more than 2500 patients has consolidated the clinical evidence for rupatadine in allergic rhinoconjunctivitis in adults and children (level of evidence Ia, recommendation A). Other recent advances include observational studies of rupatadine in everyday clinical practice situations and approval of a new formulation (1 mg/ml oral solution) for use in children. In this reappraisal, we revisit some key properties and pivotal clinical studies of rupatadine and examine new clinical data in more detail including studies that measured health-related quality of life and studies that investigated the efficacy and safety of rupatadine in other indications such as acquired cold urticaria, mosquito bite allergy and mastocytosis.

Respiratory allergies: a general overview of remedies, delivery systems, and the need to progress

The spread of respiratory allergies is increasing in parallel with the alarm of the scientific community. Evidently, our knowledge of the onset mechanisms of these diseases and, as a consequence, of the available remedies is inadequate. This review provides a brief, general description of current therapeutic resources and the state of research with regard to both drugs and medical devices in order to highlight their limits and the urgent need for progress. Increasing the amount of basic biochemical research will improve our knowledge of such onset mechanisms and the potential efficacy of therapeutic preparations.

Frequency of migraine in patients with allergic rhinitis

Objectives: Allergic rhinitis (AR) is an IgE mediated disease which is released by activation of mast cells and basophils, and often leads to sinus headache. Histamine which is the key mediator in the pathogenesis of AR, also plays an important role in the pathogenesis of migraine with nitric oxide (NO). Aim of our study was to investigate the frequency of migraine in patients with AR.

Methodology: Headache assessment and neurological examination was performed on patients diagnosed as AR in the outpatient ear nose and throat clinic with age-matched controls. Participants with headache were classified according to the International Headache Society criteria, and migraine frequency was investigated in the patients with AR and control groups.

Results: Migraine headache was detected in 50% of the patients with AR. Among these, 95% were migraine without aura, and 5% were migraine with aura. Migraine frequency in the control group was 18.75% in the control group, and all was migraine without aura. Migraine frequency in the patients with AR was four times higher when compared with the control group.

Conclusion: While a histamine and IgE associated common mechanism is responsible in the pathogenesis of AR and migraine, not only sinus headache but also migraine headache should be kept in mind. Headache assessment of the patients with AR, and in case of headache existence, referral of these patients to neurology outpatient clinics for differential diagnosis and, to maintain appropriate therapy should not be forgotten.

Safety evaluation of desloratadine in allergic rhinitis

INTRODUCTION

Desloratadine is a biologically active metabolite of second-generation antihistamine loratadine. It is also indicated for the treatment of allergic diseases, including allergic rhinitis.

AREAS COVERED

A Medline search was conducted to identify preclinical and clinical studies of desloratadine. This was supplemented with additional articles obtained from online sources. The focus of this review is on the safety profile of desloratadine.

EXPERT OPINION

The review of these data indicates that the safety profile of desloratadine is similar to other second-generation antihistamines. Desloratadine is highly selective for histamine H₁-receptors, does not cross the blood-brain barrier (BBB), and has minimal adverse events (very low sedation rate), with a better safety and tolerability than first-generation antihistamines. Desloratadine is safe and well tolerated without having central nervous system (CNS) or cardiovascular effects and with low drug interaction.