Levocetirizine: a review of its use in the management of allergic rhinitis and skin allergies

Volumetric and conductivity studies of the interaction between levocetirizine dihydrochloride and the amino acids l-alanine and l-glutamine in aqueous solutions

Levocetirizine dihydrochloride (LCTZ) is a second-generation antihistamine known for its efficacy without sedation. However, the binding mechanism with plasma protein which makes it devoid of sedative effects is yet to be uncovered. In this study, we elucidated thermodynamic parameters of solute-solvent and solute-cosolute interactions between LCTZ, and the amino acids l-alanine (Ala) and l-glutamine (Gln) in aqueous solutions. The volumetric and conductance parameters were calculated using the experimental density and conductance data of aqueous solutions of Ala and Gln (concentration range of 0.02-0.20 mol kg^-1) and LCTZ (concentration range of 0.01, 0.07, and 0.13 mol kg^-1) at 298.15, 303.15, 308.15, and 313.15 K. Volumetric analysis study revealed that the apparent molar volume (V_φ), limiting apparent molar volume (V_φ ⁰), and Masson's coefficient (S_v) values indicated predominantly solute-solvent interactions that were influenced by the solute's concentration and temperature. Meanwhile, partial molar expansibilities (E_φ ⁰), transfer volume Δ_trV_φ ⁰ and Hepler's constant (δ²V₀/δT²) established the solution system's structure-breaking tendency. The Gibb's free energy (ΔG₀) values derived from conductometry data indicated the system's spontaneity. These calculated constants provided a detailed understanding of the different types of intermolecular interactions found in the ternary (LCTZ + water + amino acids) system.

Nano-Spray-Dried Levocetirizine Dihydrochloride with Mucoadhesive Carriers and Cyclodextrins for Nasal Administration

Antihistamines such as levocetirizine dihydrochloride (LC) are commercially used in oral tablets and oral drops to reduce allergic symptoms. In this study, LC was nano-spray-dried using three mucoadhesive polymers and four cyclodextrin species to form composite powders for nasal administration. The product was composed of hydroxypropyl methylcellulose polymer, including LC as a zwitterion, after neutralization by NaOH, and XRD investigations verified its amorphous state. This and a sulfobutylated-beta-cyclodextrin sodium salt-containing sample showed crystal peaks due to NaCl content as products of the neutralization reaction in the solutions before drying. The average particle size of the spherical microparticles was between 2.42 and 3.44 µm, except for those containing a polyvinyl alcohol excipient, which were characterized by a medium diameter of 29.80 µm. The drug was completely and immediately liberated from all the samples at pH 5.6 and 32 °C; i.e., the carriers did not change the good dissolution behavior of LC. A permeability test was carried out by dipping the synthetic cellulose ester membrane in isopropyl myristate using modified horizontal diffusion cells. The spray-dried powder with β-cyclodextrin showed the highest permeability (188.37 µg/cm²/h), as this additive was the least hydrophilic. Products prepared with other cyclodextrins (randomly methylated-beta-cyclodextrin, sulfobutylated-beta-cyclodextrin sodium salt and (hydroxypropyl)-beta-cyclodextrin) showed similar or slightly higher penetration abilities than LC. Other polymer excipients resulted in lower penetration of the active agent than the pure LC.

Parkinsonism Attenuation by Antihistamines via Downregulating the Oxidative Stress, Histamine, and Inflammation

Parkinson disease (PD) is a neurodegenerative disorder of the motor activity of the brain, regulated by dopaminergic neurons of substantia nigra, resulting in an increased density of histaminergic fibers. This study was aimed to evaluate the effects of H1 antagonist's ebastine and levocetirizine in PD per se and in combination. Animals were divided into 9 groups (n = 10). Group 1 received carboxymethyl cellulose CMC (1 mL/kg). Group II was treated with haloperidol (1 mg/kg) (diseased group). Group III was treated with levodopa/carbidopa (levo 20 mg/kg). Groups IV and V were treated with ebastine at dose levels of 2 and 4 mg/kg, respectively. Groups VI and VII were treated with levocetirizine at dose levels of 0.5 and 1 mg/kg, respectively. Group VIII was treated with ebastine (4 mg/kg) + levo (20 mg/kg) in combination. Group IX was treated with levocetirizine (1 mg/kg) + levo (20 mg/kg). PD was induced with haloperidol (1 mg/kg iv, once daily for 23 days) for a duration of 30 min. Behavioral tests like rotarod, block and triple horizontal bars, actophotometer, and open field were performed. Biochemical markers of oxidative stress, i.e., SOD, CAT, GSH, MDA, dopamine, serotonin, and nor-adrenaline and nitrite, were determined. Histamine, mRNA expression of α-synuclein, and TNF-α level in the serum and brain of mice were analyzed. Endogenous biochemical markers were increased except mRNA expression of α-synuclein, which was reduced. In combination therapy with the standard drug, ebastine (4 mg/kg) significantly improved the cataleptic state and dopamine levels, but no significant difference in the renal and liver functioning tests was observed. This study concluded that ebastine (4 mg/kg) might work in the treatment of PD as it improves the cataleptic state in haloperidol-induced catalepsy.

Levocetirizine and montelukast in the COVID-19 treatment paradigm

Levocetirizine, a third-generation antihistamine, and montelukast, a leukotriene receptor antagonist, exhibit remarkable synergistic anti-inflammatory activity across a spectrum of signaling proteins, cell adhesion molecules, and leukocytes. By targeting cellular protein activity, they are uniquely positioned to treat the symptoms of COVID-19. Clinical data to date with an associated six-month follow-up, suggests the combination therapy may prevent the progression of the disease from mild to moderate to severe, as well as prevent/treat many of the aspects of ‘Long COVID,’ thereby cost effectively reducing both morbidity and mortality. To investigate patient outcomes, 53 consecutive COVID-19 test (+) cases (ages 3–90) from a well-established, single-center practice in Boston, Massachusetts, between March – November 2020, were treated with levocetirizine and montelukast in addition to then existing protocols [2]. The data set was retrospectively reviewed. Thirty-four cases were considered mild (64%), 17 moderate (32%), and 2 (4%) severe. Several patients presented with significant comorbidities (obesity: n = 22, 41%; diabetes: n = 10, 19%; hypertension: n = 24, 45%). Among the cohort there were no exclusions, no intubations, and no deaths. The pilot study in Massachusetts encompassed the first COVID-19 wave which peaked on April 23, 2020 as well as the ascending portion of the second wave in the fall. During this period the average weekly COVID-19 case mortality rate (confirmed deaths/confirmed cases) varied considerably between 1 and 7.5% [37]. FDA has approved a multicenter, randomized, placebo-controlled, Phase 2 clinical trial design, replete with electronic diaries and laboratory metrics to explore scientific questions not addressed herein.

Chemical Probes for Histamine Receptor Subtypes

Ligands with different properties and different selectivity are highly needed for in vitro and in vivo studies on the (patho)physiological influence of the chemical mediator histamine and its receptor subtypes. A selection of well-described ligands for the different receptor subtypes and different studies is shown with a particular focus on affinity and selectivity. In addition, compounds with radioactive or fluorescence elements will be presented with their beneficial use for other species or different investigations.

Identification, Isolation and Characterization of a Pharmaceutical Impurity in Levocetirizine Hydrochloride

Background:

Levocetirizine is chemically know as (R)-(-)-2-[4-(4-chlorobenzhydryl)-1- piperazinyl]-ethoxy acetic acid dihydrochloride. Many publications have reported the synthetic routes of levocetirizine. Several related substances have been detected in levocetirizine hydrochloride drug substances. In our study, a pharmaceutical impurity, at the level of >0.1% w/w, was isolated, purified and identified. It is not included in the European Pharmacopoeia (EP).

Objective:

Identification, isolation and characterization of a new pharmaceutical impurity in levocetirizine hydrochloride.

Methods:

The impurity was enriched by normal phase silica gel, and was further purified by semipreparative HPLC. It was separated from the crystallization mother liquor of levocetirizine hydrochloride for the first time. Mass spectrometry and nuclear magnetic resonance spectroscopy are the ultimate tools in structure elucidation.

Results:

The structure was identified as levocetirizine quaternary ammonium. The formation mechanisms of the impurity are also presented. The method was applied to the determination of the impurity in levocetirizine hydrochloride in real samples.

Conclusion:

The method was applied to the determination the impurity of levocetirizine hydrochloride in real samples.

Prescribed drugs containing nitrogen heterocycles: an overview

Heteroatoms as well as heterocyclic scaffolds are frequently present as the common cores in a plethora of active pharmaceuticals natural products. Statistically, more than 85% of all biologically active compounds are heterocycles or comprise a heterocycle and most frequently, nitrogen heterocycles as a backbone in their complex structures. These facts disclose and emphasize the vital role of heterocycles in modern drug design and drug discovery. In this review, we try to present a comprehensive overview of top prescribed drugs containing nitrogen heterocycles, describing their pharmacological properties, medical applications and their selected synthetic pathways. It is worth mentioning that the reported examples are actually limited to current top selling drugs, being or containing N-heterocycles and their synthetic information has been extracted from both scientific journals and the wider patent literature.

Levocetirizine Oral Disintegrating Tablet: A Randomized Open-Label Crossover Bioequivalence Study in Healthy Japanese Volunteers

Levocetirizine is classified as a second‐generation antihistamine. Levocetirizine is available for the treatment of allergic disorders such as allergic rhinitis and chronic idiopathic urticaria. This was a single‐center, single‐dose, open‐label, randomized, 2‐way crossover study in healthy Japanese male subjects consisting of 2 parts. Part 1 compared the bioavailability of levocetirizine oral disintegrating tablet (ODT) and levocetirizine immediate‐release tablet (IRT) taken with water in the fasted state in 24 subjects; all subjects completed this part of the trial. In part 2, the bioavailability of levocetirizine ODT without water was compared with that of levocetirizine IRT with water in the fasted state in 48 subjects; 47 subjects completed this part of the trial. Bioequivalence was demonstrated between levocetirizine IRT 5 mg and ODT 5 mg. The safety profiles were generally similar between levocetirizine ODT and levocetirizine IRT, with no serious adverse events, deaths, or adverse events leading to withdrawal reported during the study.

Antipruritic Placebo Effects by Conditioning H1-antihistamine

OBJECTIVE

Allergic rhinitis symptoms can be reduced by behaviorally conditioning antihistamine. It is unclear whether these findings extend to histamine-induced itch or work when participants are informed about the conditioning procedure (open-label conditioning). The current study aims to investigate the efficacy of (open-label) antipruritic behavioral conditioning for histamine-induced itch.

METHODS

Healthy participants (n = 92; 84% female) were randomized to I) an open-label conditioned, II) closed-label conditioned, III) conditioned-not-evoked control, or IV) nonconditioned control group. A two-phase conditioning paradigm was used. During acquisition, a conditioned stimulus (CS; distinctively tasting beverage) was repeatedly paired with the H1-antihistamine levocetirizine (groups I-III). During evocation, the CS was paired with placebo (I, II), or instead of the CS, water was paired with placebo (III). The nonconditioned control group (IV) received CS with placebo in both phases. Itch after histamine iontophoresis and physiological data (i.e., spirometry, heart rate, skin conductance) were assessed. Combined conditioned and combined control groups were first compared, and analyses were repeated for separate groups.

RESULTS

Marginally lower itch was reported in the combined conditioned compared with the control groups (F(1,88) = 2.10, p = .076, ηpartial = 0.02); no differences between separate groups were found. No effects on physiological data were found, except for heart rate, which reduced significantly and consistently for control groups, and less consistently for conditioned groups (group by time interaction: F(7,80) = 2.35, p = .031, ηpartial = 0.17).

CONCLUSION

Limited support was found for the efficacy of antipruritic behavioral conditioning, regardless of whether participants were informed about the conditioning procedure. The application of open-label conditioning in patient populations should be further researched.

TRIAL REGISTRATION

www.trialregister.nl; ID NTR5544.

A case of levocetirizine-induced liver injury

Levocetirizine is a second-generation nonsedative antihistaminic agent that has been demonstrated to be safe and effective for treating allergic disease. There was only one case report of levocetirizine-induced liver toxicity, but a liver biopsy was not performed. In this article, we present the first case of levocetirizine-induced liver injury with histologic findings. A 48-year-old man was hospitalized with jaundice and generalized pruritus that had developed after 2 months of therapy with levocetirizine for prurigo nodularis. Laboratory findings revealed acute hepatitis with cholestasis. A liver biopsy demonstrated portal inflammation and hepatitis with apoptotic hepatocytes. The patient fully recovered 3 weeks after withdrawing levocetirizine. Although levocetirizine is safe and effective, physicians should be aware of its potential hepatotoxicity.

Concomitant drugs with low risks of drug-drug interactions for use in oncology clinical trials

BACKGROUND

Drug-drug interactions (DDIs) may occur with investigational drugs and affect patient safety, trial outcomes, and drug development. A list of preferred drugs with minimal risks of DDIs for treatment of symptoms or comorbidities frequently encountered by cancer patients would be helpful.

METHODS

We reviewed the literature to assess DDIs reported for the main drugs available for treatment of symptoms/comorbidities frequently encountered by cancer patients. Reviews and relevant original articles cited were retrieved and analyzed, and the following data were collected and double-checked: pharmacological properties; effects, if any, of drugs on CYP enzymes, membrane transporters, and QT interval; and involvement in significant DDIs.

RESULTS

A list of preferred drugs with minimal risks of DDIs was compiled.

CONCLUSION

Acknowledging for heterogeneity in data sources, prevention of unexpected DDIs during clinical trials may be improved by using this list of preferred drugs for the management of study patient's symptoms.

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.

Comparison of levocetirizine pharmacokinetics after single doses of levocetirizine oral solution and cetirizine dry syrup in healthy Japanese male subjects

Objective

Levocetirizine, the R-enantiomer of cetirizine, is classified as a second generation antihistamine used for the treatment of allergic disorders. This study aimed to compare exposure to levocetirizine when given as levocetirizine oral solution (OS) 5 mg to that when given as cetirizine dry syrup (DS) 10 mg, which contains equal proportions of levocetirizine and dextrocetirizine, in healthy Japanese male subjects.

Methods

The study was conducted in an open-label, single dose, randomized and two-way cross-over design. Eligible subjects were allocated to one of two groups and received either levocetirizine OS 5 mg or cetirizine DS 10 mg under fasting conditions, and the alternate treatment after a 7-days washout period. Serial blood samples were taken after each administration, and plasma levocetirizine concentrations were determined using a validated LC-MS/MS method. Pharmacokinetic parameters were calculated by using non-compartmental analysis. Comparisons of levocetirizine pharmacokinetics were conducted with maximum concentration (C_max) and the area under the plasma concentration-time curve from dosing until 48 h post-dose (AUC_0–48) after each treatment.

Clinical Trial registration number

ClinicalTrials.gov identifier is NCT01622283

Results

The mean C_max and AUC_0–48 of levocetirizine after a single dose of levocetirizine OS 5 mg and cetirizine DS 10 mg were 203.3 ± 42.49 ng/mL and 1814.9 ± 304.22 ng.hr/mL, and 196.5 ± 31.31 ng/mL and 1710.5 ± 263.31 ng hr/mL, respectively. The ratios and the 90% CIs of the geometric least squares means ratios of C_max and AUC_0–48 were 1.027 (0.968–1.091) and 1.059 (1.024–1.094), respectively.

Limitation

The small sample size and single dose design of this study prevent definitive conclusions regarding the pharmacokinetics and safety of levocetirizine OS in a Japanese patient population being made. Study limitations include conducting the study in adult males, not in children.

Conclusions

Levocetirizine exposure in plasma was equivalent when given as levocetirizine OS 5 mg and as cetirizine DS 10 mg. Both preparations were safe and well-tolerated in healthy Japanese male subjects.

Levocetirizine inhibits migration of immune cells to lymph nodes and induces treg cells in a murine type I allergic conjunctivitis model

Background & Purpose:

Levocetirizine is a histamine H(1) receptor antagonist. Here, we utilised DO11.10TCR transgenic mice to establish an antigen-specific T cell-dependent allergic conjunctivitis (AC) model to determine the effect of the topical application of an ophthalmic formulation of Levoceritizine as a treatment for AC.

Experimental Approach:

DO11.10 mice (n=6/each) were exposed to ovalbumin (OVA, 50 µg) and treated with a Levocetirizine ophthalmic formulation (0.001–0.02% v/w) or placebo (vehicle) for 24–72 h. Serum, aqueous/vitreous humour and conjunctiva were obtained. Immunoglobulin (Ig)-E, interleukin (IL)-10 and lipoxin (LX)A₄ were determined by ELISA. Levels of tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interferon (IFN)-γ and 18rS expression were measured by RT-PCR. Proportions of total and activated antigen-presenting cells (APC), recruited T lymphocytes (CD4+), activated T lymphocytes (CD25+) and T regulatory cells (Treg) were measured by flow cytometry.

Key Results:

OVA exposure induced AC in the animal model indicated by increased expression of LXA₄, TNF-α and TGF-β. Levocetirizine treatment (0.01–0.02% v/w) reduced LXA₄ in the eye humours. This treatment approach increased systemic IL-10 secretion and reduced TNF-α and TGF-β expression in conjunctiva without changing IFN-γ expression. Levocetirizine reduced APC levels in draining lymph nodes but increased the proportion of total lymphocytes recruited and their differentiation to Treg cells.

Conclusions & Implications:

Levocetirizine effectively reduces the activation and migration of APC to local draining lymph nodes and induces differentiation of Treg cells as one possible mechanism of its anti-inflammatory action.

Levocetirizine Inhibits Rhinovirus-Induced Up-Regulation of Fibrogenic and Angiogenic Factors in Nasal Polyp Fibroblasts

Background

Up-regulation of matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF) beta, may contribute to the formation of nasal polyps (NPs). Rhinovirus (RV) infection enhances expression of MMP-2, MMP-9, and VEGF in NP fibroblasts and of TGF-beta in respiratory epithelial cells. We investigated the inhibitory effects of levocetirizine (LCT) on the RV-induced expression of (1) fibrogenic (MMPs and TGF-beta) and (2) angiogenic (VEGF and TGF-beta) factors in NP fibroblasts.

Methods

NP fibroblasts obtained from 11 male patients with chronic rhinosinusitis with NPs (CRSwNPs), were infected with RV serotype 16 (RV-16) for 4 hours. Cells were treated with 50 nM of LCT 24 hours before infection and for 48 hours thereafter. Expression of MMP-2, MMP-9, VEGF, and TGF-β mRNA and protein were determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively.

Results

LCT significantly inhibited RV-induced increases in MMP-2, MMP-9, VEGF, and TGF-beta mRNA, and protein expression, in NP fibroblasts (p < 0.05 for each comparison).

Conclusion

LCT inhibits RV-induced up-regulation of fibrogenic and angiogenic factors in NP fibroblasts, suggesting that LCT may prevent NP formation in patients with CRSwNP caused by RV infection.

Administration of levocetirizine (glencet) in eczema patients.Clinical and ultrasonic assessment of the efficacy

There was a clinical and ultrasonic study of the clinical efficacy of levocetirizine as a part of a complex therapy in 60 patients with eczema. The dynamic calculation of the EASI, EQ-5D and DLQI indices as well as analysis of ultrasound showings made it possible to confirm the benefits of glencet vs. cetirizine for achieving the clinical effect. The eczema therapy with glencet contributes to the elimination of both exudative and proliferative parts of the complex pathologic chain of the disease in patients with this type of dermatosis.

Levocetirizinium dipicrate

There are two cation-dianion pairs in the asymmetric unit of the title compound, C(21)H(27)ClN(2)O(3) (2+)·2C(6)H(2)N(3)O(7) (-) {systematic name: 1-[2-(carb-oxy-meth-oxy)eth-yl]-4-[(R)-(4-chloro-phen-yl)phenyl-meth-yl]piperazine-1,4-diium bis-(2,4,6-trinitro-phenol-ate)}. The piperazine group in the levocetirizinium cation is protonated at both N atoms. The acetyl end groups form R(2) (2)(8) hydrogen-bonded motifs with adjacent cations. Each picrate anion inter-acts with the proponated N atom in the cation through a bifurcated N-H⋯O hydrogen bond, forming R(1) (2)(6) ring motifs. Strong and weak inter-molecular N-H⋯O and strong O-H⋯O hydrogen bonds, and weak π-ring and π-π stacking inter-actions [centroid-centroid distance = 3.7419 (14) Å] dominate the crystal packing, creating a three-dimensional supra-molecular structure.

Loratadine versus levocetirizine in chronic idiopathic urticaria: A comparative study of efficacy and safety

BACKGROUND

Treatment of chronic idiopathic urticaria (CIU) is challenging because of its unpredictable course and negative influence on the quality of life. New treatments are being developed, but antihistaminics remain the cornerstone of the therapeutic approach. Newer generation antihistaminics such as loratadine and levocetirizine have already proved to be safe and efficacious for CIU.

OBJECTIVE

To choose the better drug between loratadine and levocetirizine for CIU, by comparing their efficacy and safety.

METHODS

A randomized, open, outdoor-based clinical study was conducted on 60 patients of CIU, to compare the two drugs. After initial clinical assessment and baseline investigations, loratadine was prescribed to 30 patients and levocetirizine to another 30 patients for four weeks. At follow-up, the patients were re-evaluated and then compared using different statistical tools.

RESULT

The comparative study showed that the changes in differential eosinophil count (P = 0.006) and absolute eosinophil count (P = 0.003) in the levocetirizine group was statistically significant. The results of the Total Symptom Score showed better symptomatic improvement of CIU with levocetirizine as compared to loratadine. The overall incidence of adverse drug reactions was also found to be less in the levocetirizine group.

CONCLUSION

An analysis of the results of all the parameters of safety and efficacy proves the superiority of levocetirizine over loratadine for CIU.

The anti-inflammatory effects of levocetirizine--are they clinically relevant or just an interesting additional effect?

Levocetirizine, the R-enantiomer of cetirizine dihydrochloride has pharmacodynamically and pharmacokinetically favourable characteristics, including rapid onset of action, high bioavailability, high affinity for and occupancy of the H1-receptor, limited distribution, minimal hepatic metabolism together with minimal untoward effects. Several well conducted randomised clinical trials have demonstrated the effectiveness of levocetirizine for the treatment of allergic rhinitis and chronic idiopathic urticaria in adults and children. In addition to the treatment for the immediate short-term manifestations of allergic disease, there appears to be a growing trend for the use of levocetirizine as long-term therapy. In addition to its being a potent antihistamine, levocetirizine has several documented anti-inflammatory effects that are observed at clinically relevant concentrations that may enhance its therapeutic benefit. This review will consider the potential or otherwise of the reported anti-inflammatory effects of levocetirizine to enhance its effectiveness in the treatment of allergic disease.

Levocetirizine in the treatment of allergic diseases

BACKGROUND

Levocetirizine, the R-enantiomer of cetirizine dihydrochloride, is a new molecule with a potent and selective antihistamine activity.

OBJECTIVE

To investigate the evidence that levocetirizine is an effective therapy for allergic disease.

METHODS

Evaluation of published articles in English, or having an English abstract.

RESULTS

Clinical trials indicate that levocetirizine is safe and effective for the treatment of allergic rhinitis and chronic idiopathic urticaria. The compound shows a rapid onset of action, high bioavailability and affinity for the H1 receptor. Moreover, this molecule demonstrates many anti-inflammatory effects that enhance the clinical therapeutic benefit not only in short-term but also in long-term treatments, as reported in recent trials utilizing levocetirizine for several months.

CONCLUSION

Levocetirizine confirms its safe effective activity for treatment of allergic disease in both adults and children.

Levocetirizine modulates lymphocyte activation in patients with allergic rhinitis

Levocetirizine, a second generation non-sedating antihistamine that blocks the H(1) histamine receptor, may exhibit immunoregulatory properties that augment its primary pharmacological mechanism. To investigate this possibility, 13 Kuwaiti seasonal allergic rhinitis (SAR) patients were treated with levocetirizine for four weeks in comparison with a 7-member placebo-treated control group, followed by clinical evaluation and flow cytometric analysis of peripheral venous blood for inflammatory cell and lymphocyte subpopulation profiles. Relative to the controls, levocetirizine-treated patients exhibited an expected reduction in early phase allergic symptoms, including sneezing (P<0.001), nasal itching (P<0.01), nasal congestion, and running nose (P<0.001); reduced percentages of eosinophils (P<0.05); and three subpopulations of activated T lymphocytes: CD4+CD29+, CD4+CD212+, and CD4+CD54+ (P<0.05). Levocetirizine treatment also correlated with a significant increase in the percentage of CD4+CD25+ T cells (P<0.001). The ability of levocetirizine to reduce percentage representation of cell phenotypes known to contribute to inflammatory tissue damage (eosinophils, CD4+CD29+, CD4+CD212+, and CD4+CD54+) and expand percentages of CD4+CD25+, which may include protective immunoregulatory (Treg) cells, indicates that the drug has pharmacological potential beyond the immediate effects of H(1) histamine-receptor inhibition. Although the present data does not define a therapeutic mechanism, the results reported here establish important trends that may be used to guide future mechanistic examination of immunoregulatory capacity of H(1) inhibitors.

Levocetirizine in persistent allergic rhinitis: continuous or on-demand use? A pilot study

BACKGROUND

Allergic rhinitis is a high-prevalence disease that affects quality of life (QOL), sleep quality and productivity of patients. According to the ARIA initiative, it is classified as intermittent and persistent, the latter being the most troublesome.

METHODS

The aim of this randomized, open-label, 6-month, pilot study was to determine whether levocetirizine 5 mg administered continuously once daily in the morning was better than levocetirizine 5 mg on-demand in symptomatic subjects with persistent allergic rhinitis. Total and individual symptom scores were recorded in a diary card throughout the study. QOL, quality of sleep, nasal cytology, rate of drug intake, and safety were also assessed at pre-defined time-points.

RESULTS

In all, adult patients (31 in each group) were enrolled, of whom 22 dropped out. Both treatment regimens considerably decreased the total and individual symptoms scores from baseline and achieved similar levels up to week 14. Continuous treatment was generally better than on-demand from week 15 onwards, reaching statistical significance from weeks 17 to 21 (from week 19 to 21 for nasal pruritus). Both regimens substantially improved QOL and sleep quality. Both treatments were well tolerated, although the on-demand group reported more adverse events.

CONCLUSION

The present open label study in 62 patients indicates that levocetirizine 5 mg reliably controls persistent rhinitis over a period of 6 months, and shows a trend to be more effective in controlling the symptoms of rhinitis, improving QOL and decreasing nasal inflammation, when administered as long-term continuous therapy rather than as on-demand therapy.

New oral H1 antihistamines in children: facts and unmeet needs

BACKGROUND

Second-generation antihistamines differ from first-generation ones because of their elevated specificity and affinity for peripheral H1-receptors and because of their lower penetration to the central nervous system, having fewer sedative effects as a result. Over the last few years, new compounds with different pharmacokinetic properties have been synthesized. More recent improvements of the molecules, generally in the form of active metabolites, led to the synthesis of new-generation antihistamines.

METHODS

Recommendations on the minimum criteria that would have to be met for compounds to be classified as new-generation antihistamines have been recently established by a consensus statement. In the past, the pharmacokinetics and pharmacodynamics of H1 antihistamines have not been optimally investigated in the pediatric population, especially in infants and young children.

RESULTS

The pharmacology of second-generation H1 antihistamines has been investigated relatively deeper than old antihistamines in children. In the pediatric population, clinical studies with new-generation antihistamines are still limited in number and, with rare exceptions, of brief duration. Comparative trials on the efficacy and safety between different compounds are also lacking.

CONCLUSIONS

Properly designed, long-term trials with new-generation H1 antihistamines need to be performed in single age groups, in order to better define the effects of these drugs in all pediatric population.

H1 antihistamines: current status and future directions

In this review, we compare and contrast the clinical pharmacology, efficacy, and safety of first-generation H1 antihistamines and second-generation H1 antihistamines. First-generation H1 antihistamines cross the blood-brain barrier, and in usual doses, they potentially cause sedation and impair cognitive function and psychomotor performance. These medications, some of which have been in use for more than 6 decades, have never been optimally investigated. Second-generation H1 antihistamines such as cetirizine, desloratadine, fexofenadine, levocetirizine, and loratadine cross the blood-brain barrier to a significantly smaller extent than their predecessors. The clinical pharmacology, efficacy, and safety of these medications have been extensively studied. They are therefore the H1 antihistamines of choice in the treatment of allergic rhinitis, allergic conjunctivitis, and urticaria. In the future, clinically advantageous H1 antihistamines developed with the aid of molecular techniques might be available.

A review of the role of levocetirizine as an effective therapy for allergic disease

BACKGROUND

Levocetirizine is the R-enantiomer of cetirizine dihydrochloride with pharmacodynamically and pharmacokinetically favourable characteristics.

OBJECTIVE

To review the evidence that levocetirizine is an effective therapy for allergic disease.

METHODOLOGY

Relevant articles in English or with English abstracts were identified from systematic PubMed searches.

RESULTS

Levocetirizine has high bioavailability, high affinity for and occupancy of the H1 receptor, rapid onset of action, limited distribution and minimal hepatic metabolism. Clinical trials indicate that it is safe and effective for the treatment of allergic rhinitis and chronic idiopathic urticaria in adults and children with a minimal number of untoward effects. It is also becoming clearer that, in addition to its being a potent antihistamine, levocetirizine has several anti-inflammatory effects that are observed at clinically relevant concentrations that may enhance its therapeutic benefit. Furthermore, there appears to be a growing trend for the use of levocetirizine as long-term therapy in addition to it being used as a treatment for the immediate short-term manifestations of allergic disease.

CONCLUSION

Levocetirizine is an effective and safe treatment for use in adults and children with allergic disease.

Some pharmacokinetic aspects of the lipophilic terfenadine and zwitterionic fexofenadine in humans

Fexofenadine, an active metabolite of the second-generation histamine H1 receptor antagonist (antihistamine) terfenadine, does not have the disadvantage of QT prolongation. In addition, unlike first-generation antihistamines, it is associated with few CNS adverse effects. Chemically, fexofenadine has a zwitterionic structure that makes it an interesting molecule for use as an oral drug. Fexo-fenadine has negligible hepatic metabolism in humans, and is recovered mainly in the faeces in an unchanged form after oral administration. The absolute oral bioavailability of fexofenadine in humans is not known because of a lack of studies of intravenous administration of this agent. Its apparent elimination half-life (t1/2) ranges from 3 to 17 hours and is highly dependent on study design, i.e. the length of blood sampling. This large discrepancy might be associated with a 'flip-flop' phenomenon caused by slow absorption of the zwitterionic molecule. This review summarises the available literature related to the absorption, elimination and excretion of fexofenadine and terfenadine. Based on these data, the volume of distribution, t1/2 and oral bioavailability of fexofenadine in humans are estimated. Understanding these pharmacokinetic aspects of this drug might be very useful for medicinal chemists utilising fexofenadine/terfenadine as an example for designing zwitterionic compounds to combat cardiotoxicity and other issues related to basic and lipophilic molecules.

Inhibition of allergen-induced wheal and flare reactions by levocetirizine and desloratadine

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The reproducible and standardized histamine-induced wheal and flare model helps identify the objective effectiveness of antihistamines in humans, as well as their differences in onset and duration of action. Some of the newest antihistamines have already been compared in a head-to-head setting using this model. However, their objective action at inhibiting the allergen-induced wheal and flare response has not been reported yet.

WHAT THIS STUDY ADDS

The time-response study presented here shows the objective activity of two of the newest generation of antihistamines, levocetirizine and desloratadine, at inhibiting the allergen-induced wheal and flare response in a randomized, cross over, placebo-controlled trial. This model is interesting to the clinical setting since allergic subjects are recruited, and the response to allergen involves mast cell degranulation and release of numerous vasoactive and pro-inflammatory mediators additionally to histamine. In addition, this study reports receptor occupancy for both antihistamines at therapeutic dosage, leading to analysis of potential differences in activity. This study clearly shows the potential anti-inflammatory properties of desloratadine and levocetirizine in their skin activity when allergen is the challenging agent as occurs in the clinical situation.

AIMS

To evaluate the inhibitory activity of the new-generation antihistamines levocetirizine and desloratadine at their therapeutic doses on the allergen-induced wheal and flare reaction at 1.5 h, 4 h, 7 h, 12 h and 24 h postdose, and to measure their plasma and skin concentrations.

METHODS

A double-blind, randomized, cross-over, placebo-controlled study in 18 allergic subjects was carried out. The time-response of the wheal and flare reaction areas under the curve (AUC) were compared by anova.

RESULTS

Both antihistamines significantly (P < 0.001) inhibited the allergen-induced wheal and flare reactions compared with placebo. Levocetirizine was significantly more potent than desloratadine. Mean +/- SEM wheal AUC(0-24 h) was 506.4 +/- 81.0 with levocetirizine and 995.5 +/- 81.0 mm(2) h with desloratadine as compared with placebo (1318.5 +/- 361.0 mm(2) h). Flare AUC(0-24 h) was 5927.3 +/- 1686.5 and 15838.2 +/- 1686.5 mm(2) h, respectively [P < 0.001 for both compared with placebo (22508.2 +/- 7437.1 mm(2) h)]. Levocetirizine showed significant inhibition of wheal and flare already at 1.5 h postdose compared with placebo (P <or= 0.001); desloratadine achieved a significant effect only after 4 h. The mean total plasma concentration at 12 h and 24 h after intake was higher for levocetirizine (58.1 +/- 13.4 and 20.0 +/- 8.1 ng ml(-1), respectively) as compared with desloratadine (0.82 +/- 0.24 and 0.45 +/- 0.16 ng ml(-1)). Similarly, higher mean unbound skin concentrations were observed for levocetirizine 24 h after intake (1.80 ng g(-1)) than for desloratadine (0.07 ng g(-1)). This was associated with greater receptor occupancy for levocetirizine (54%) than desloratadine (34%) at 24 h.

CONCLUSIONS

Levocetirizine suppressed the cutaneous allergic reactions with a higher potency than desloratadine, which correlated with its high receptor occupancy. Receptor occupancy rather than drug affinity or plasma half-life is more representative of antihistamine potency.