Facial thermography is a sensitive tool to determine antihistaminic activity: comparison of levocetirizine and fexofenadine

Antihistamine effects and safety of fexofenadine: a systematic review and Meta-analysis of randomized controlled trials

Background

As a new generation antihistamine, fexofenadine has been widely used in allergic diseases. However, there is still a lack of collective evidence regarding the antihistamine effects and safety profiles of fexofenadine relative to other antihistamine drugs and placebo. Therefore, we aimed to systematically evaluate the antihistamine effects and safety of fexofenadine.

Methods

An electronic literature search of randomized controlled trials (RCTs) was performed using Embase, Cochrane and PubMed from establishment to January 1st, 2018. RCTs comparing the antihistamine effects or safety (adverse events, sedative effects, and cognitive/psychomotor function) of fexofenadine with either other antihistamines or placebo for healthy subjects and patients with allergy were selected.

Results

Fifty-one studies of 14,551 participants met the inclusion criteria. When compared with the first-generation antihistamines, fexofenadine produced significantly lower adverse events frequency (OR = 0.446; 95% CI: 0.214 to 0.929, P = 0.031), significantly lower sedative effects frequency (OR = 0.265; 95% CI: 0.072 to 0.976, P = 0.046) and significantly less change of all cognitive/psychomotor function. When compared with the second-generation antihistamines, fexofenadine produced significantly marginal sedative effects (OR = 0.59; 95% CI, 0.38 to 0.93; P = 0.02) and significantly less change of most of the cognitive/psychomotor function. When compared with placebo, fexofenadine produced more significant antihistamine effects.

Conclusions

Fexofenadine has a positive antihistamine effect, which is probably no worse than the second-generation antihistamines. Fexofenadine probably has a favorable safety profile, which is more likely better than that of the first-generation antihistamines. There is lack of data to support that fexofenadine has a better overall safety profile compared to the second-generation antihistamines, however, some presently available evidence on sedative effects and certain aspects of cognitive/psychomotor function favors fexofenadine. Therefore, fexofenadine may be worthy of recommendation for safety related workers.

Investigation of the antiallergic activity of olopatadine on rhinitis induced by intranasal instillation of antigen in sensitized rats using thermography

Background

The main symptoms of allergic rhinitis (AR) are sneezing, rhinorrhea and nasal obstruction. It was reported that the nasal skin temperature after intranasal administration of histamine or grass pollen rose. In patients with AR, the levels of nerve growth factor (NGF) and vascular endothelial growth factor (VEGF) have increased in nasal fluids and mucosa.

Objective

The present study were to determine the temperature changes of the nose in rat allergic rhinitis model, and if olopatadine, an antiallergic agent with histamine H1 receptor antagonistic action, proved to be effective, were studied the productions of NGF and VEGF in nasal lavage fluids (NALF). In the present study, we used ovalbumin (OVA)-sensitized rats as an animal model of nasal allergy and examined the effects of olopatadine on the skin temperature of the nose area, and the productions of NGF and VEGF in NALF.

Methods

The temperature changes of the nose area were carried out with thermo tracer in rat passively sensitized with OVA antiserum. The numbers of sneezing episodes were counted and, NGF and VEGF levels in NALF were examined using the specific ELISA.

Results

In OVA-sensitized rats, the number of sneezing episodes increase and the nasal skin temperature rise were provoked after OVA challenge. The levels of NGF and VEGF in NALF also were increased. Olopatadine reduced the increased frequency of sneezing and the nasal skin temperature rise. It also inhibited the increased NGF and VEGF productions in NALF.

Conclusion

The nasal skin temperature after OVA challenge rose even in OVA-sensitized rats. These results suggest that the suppression of the increased NGF and VEGF levels might partially be involved in the improvement of allergy-like behavior (sneezing and nasal skin temperature rise) by the treatment of olopatadine.

Improving SAR symptoms with levocetirizine: evaluating active and placebo effects in pollen challenge vs. natural exposure studies

OBJECTIVE

Despite a plethora of published data on levocetirizine, no meta-analyses exist on the effect of study design, and covariates like age, gender, and baseline symptom severity on treatment response. The objective of this study was the efficacy of levocetirizine 5  mg tablets and matching placebo at reducing allergy symptoms in adult subjects with seasonal allergic rhinitis under various pollen exposure study conditions and by age, gender and baseline symptom severity.

METHODS

This was a meta-analysis of original reports from randomized, double-blind, placebo-controlled studies. Clinical studies without detailed reports, open-label, non-randomized and non-controlled studies, or paediatric studies, were excluded. Study subjects were divided into an environmental exposure (EE) group or a natural exposure (NE) group.

RESULTS

Data from 3640 subjects were analysed (n = 2174 for levocetirizine, n = 1466 for placebo). The overall results confirmed the efficacy of levocetirizine 5  mg, with an approximately 40% symptom score improvement from baseline, in both the EE and NE groups. While levocetirizine showed no gender- or age-related differences in efficacy, female subjects responded better to placebo in the EE, but not in the NE group; younger subjects (<30 years of age) responded less favourably to placebo compared with older subjects (≥ 50 years of age). Levocetirizine was consistently superior to placebo regardless of baseline symptom score levels. The highest significance levels between the active and placebo groups were observed in subjects sensitized to animal dander and grass.

CONCLUSIONS

Differences between an oral antihistamine and placebo in clinical studies of allergic rhinitis might be due to a different response to placebo rather than to the active drug. Levocetirizine seems to have consistent efficacy regardless of age, gender, and baseline scores.

Long-term reduction in local inflammation by a lipid raft molecule in atopic dermatitis

BACKGROUND

The complex pathogenesis of atopic dermatitis (AD) is guided by cell surface receptor-mediated signal transduction regulated in lipid rafts. Miltefosine is a raft-modulating molecule targeting cell membranes. With this controlled clinical study, the clinical and immunomodulatory efficacy of miltefosine was investigated in patients with AD in comparison with a topical corticosteroid treatment.

METHODS

Sixteen patients with AD were treated topically with miltefosine and hydrocortisone localized on representative AD target lesions for 3 weeks. To assess the clinical efficacy, the three item severity (TIS) score was evaluated before, during and after treatment as well as after 4-week-follow-up period. To study the anti-inflammatory effect of miltefosine on the cellular T cell pattern, skin biopsies were analysed before and after treatment.

RESULTS

The TIS score dropped in both groups significantly after treatment. A carry-over effect was exclusively seen for miltefosine after discontinuing the treatment. These findings were substantiated by thermographic imaging with a significant decrease in the maximum temperature (T(max)) after miltefosine application (P = 0.034, DeltaT(max) = 1.7 degrees C [2.1-3.9]). Immunohistochemically, a reduction in lesional CD4(+)-infiltrating T cells was observed in both treatments. Moreover, increased FoxP3(+) cells were present in the skin after miltefosine treatment (before 5.4% [1.9-9.8], after 6.2% [3.5-9.5]).

CONCLUSION

We demonstrate that miltefosine is locally active in patients with AD and led to a sustained clinical improvement in local skin inflammation. Moreover, the increased frequency of FoxP3(+) cells in the skin of patients with AD suggests its immunomodulatory properties.

From pharmacokinetics to therapeutics

Whilst pharmacokinetics describe the relationship between dose levels and concentration-time profiles of a drug in the body and pharmacodynamics describe the concentration-response relationships, pharmacokinectics-pharmacodynamics(PK-PD) models link these two items providing a framework for modelling the time course of drug response. In this chapter, PK-PD models, describing the therapeutic effects of drugs used for the therapy of allergic diseases have been reviewed. Emphasis was given also to the description of the receptor occupancy, which is tightly related to the downstream clinical response. PK - PD models describing unwanted effects were also commented. An integrated use of these models allows choosing appropriate dosing regimens and providing an objective evaluation of the benefit/risk balance.

Update on prescription and over-the-counter histamine inverse agonists in rhinitis therapy

Allergic rhinitis (AR) is associated with histamine-mediated physiologic events. The currently used histamine antagonists are all inverse agonists that bind and inactivate histamine H1 receptors. Second-generation antihistamines are much more H1-receptor selective with less central nervous system penetration than first-generation agents. Antihistamines typically are more effective in seasonal than perennial AR and do not demonstrate significant relief of nasal congestion. The recent availability of some second-generation antihistamines as over-the-counter products clearly places them as the preferred first-line treatment for mild to moderate AR based on safety when compared with first-generation over-the-counter antihistamines. The remaining prescription-only second-generation antihistamines, fexofenadine, desloratadine, and levocetirizine, all have unique attributes. Antihistamines in oral, intranasal, or intraocular formulations will likely remain among the mainstays of allergy therapeutics.

Once daily levocetirizine for the treatment of allergic rhinitis and chronic idiopathic urticaria

Levocetirizine is the pharmacologically active enantiomer of cetirizine. It is a potent histamine H-1 receptor antagonist with anti-inflammatory and antiallergic properties. The review analyses the levocetirizine's properties in terms of safety and efficacy both in allergic rhinitis and urticarioid syndromes.

Evidence-based recommendations regarding the differential diagnosis and assessment of nasal congestion: using the new GRADE system

Nasal congestion is an important symptom in nasal pathology and can be defined as an objective restriction of nasal cavity airflow because of mucosal pathology and/or increased mucus secretion (excluding anatomical variants). Using the new Grading Recommendations Assessment, Development and Evaluation system, evidence-based recommendations are made that will encompass different clinical questions regarding diagnostic modalities of nasal congestion: (i) their usefulness in assessment of presence and severity of congestion; (ii) their usefulness in assessment of etiological pathology responsible for congestion; and (iii) their usefulness in follow up and treatment effectiveness evaluation of nasal congestion.

[Antihistamines in allergic rhinitis]

Antihistamines are the first line of pharmacotherapy in allergic diseases, especially in allergic rhinitis. The article also presents the interesting 2005-2007 publications on the use of antihistamine in practical point of view, especially the newly introduced ones (desloratadine, fexofenadine, levocetirizine) and those which are to be introduced soon (rupatadine). The efficacy in skin histamine provocation model and various clinical model were discussed.

Facial thermography is a sensitive and specific method for assessing food challenge outcome

BACKGROUND

Oral challenge is widely used for diagnosing food allergy but variable interpretation of subjective symptoms may cause error. Facial thermography was evaluated as a novel, objective and sensitive indicator of challenge outcome.

METHODS

A total of 24 children with a history of egg allergy underwent oral challenge, which were scored positive when objective symptoms occurred or negative after all doses were consumed without reaction. Facial temperatures were recorded at baseline and 10-min intervals. The difference between mean and baseline temperature (DeltaT), maximum DeltaT during challenge (DeltaT(max)) and area under curve of DeltaT against time (DeltaTAUC) were calculated for predefined nasal, oral and forehead areas, and related to objective challenge outcome.

RESULTS

There were 13 positive and 11 negative challenges. Median nasal DeltaTAUC and DeltaT(max) were greater in positive compared with negative challenges (231- and 5-fold, respectively; P < 0.05). In positive challenges, nasal temperatures showed an early transient rise at 20 min, preceding objective symptoms at median 67 min. There was a sustained temperature increase from 60 min, which was reduced by antihistamines. A cut-off for nasal DeltaT(max) of 0.8 degrees C occurring within 20 min of the start of the challenge predicted outcome with 91% sensitivity (positive predictive value [PPV] 100%) and 100% specificity (negative predictive value [NPV] 93%). Subjective symptoms occurred in four of 13 positive and three of 11 negative challenges.

CONCLUSIONS

Facial thermography consistently detects a significant early rise in nasal temperature during positive compared with negative food challenges, which is evident before objective symptoms occur. Thermography may therefore provide a sensitive method to determine outcome of food challenges and investigate the pathophysiology of food allergic reactions.