Loratadine Combats Methicillin-Resistant Staphylococcus aureus by Modulating Virulence, Antibiotic Resistance, and Biofilm Genes

Methicillin-resistant Staphylococcus aureus (MRSA) has evolved to become resistant to multiple classes of antibiotics. New antibiotics are costly to develop and deploy, and they have a limited effective lifespan. Antibiotic adjuvants are molecules that potentiate existing antibiotics through nontoxic mechanisms. We previously reported that loratadine, the active ingredient in Claritin, potentiates multiple cell-wall active antibiotics in vitro and disrupts biofilm formation through a hypothesized inhibition of the master regulatory kinase Stk1. Loratadine and oxacillin combined repressed the expression of key antibiotic resistance genes in the bla and mec operons. We hypothesized that additional genes involved in antibiotic resistance, biofilm formation, and other cellular pathways would be modulated when looking transcriptome-wide. To test this, we used RNA-seq to quantify transcript levels and found significant effects in gene expression, including genes controlling virulence, antibiotic resistance, metabolism, transcription (core RNA polymerase subunits and sigma factors), and translation (a plethora of genes encoding ribosomal proteins and elongation factor Tu). We further demonstrated the impacts of these transcriptional effects by investigating loratadine treatment on intracellular ATP levels, persister formation, and biofilm formation and morphology. Loratadine minimized biofilm formation in vitro and enhanced the survival of infected Caenorhabditis elegans. These pleiotropic effects and their demonstrated outcomes on MRSA virulence and survival phenotypes position loratadine as an attractive anti-infective against MRSA.

Solubility and Physical Stability Enhancement of Loratadine by Preparation of Co-Amorphous Solid Dispersion with Chlorpheniramine and Polyvinylpyrrolidone

Loratadine (LRD), a non-sedating and slow-acting antihistamine, is often given in combination with short-onset chlorpheniramine maleate (CPM) to increase efficacy. However, LRD has poor water solubility resulting in low bioavailability. The aim of this study was to improve LRD solubility by preparing co-amorphous LRD-CPM. However, the obtained co-amorphous LRD-CPM recrystallized rapidly, and the solubility of LRD returned to a poor state again. Therefore, co-amorphous LRD-CPM solid dispersions using polyvinylpyrrolidone (PVP) as a carrier were prepared. The obtained solid dispersions were characterized using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR). The solubility, dissolution, and mechanism of drug release from the LRD-CPM/PVP co-amorphous solid dispersions were studied and compared with those of intact LRD, LRD/PVP solid dispersions, and co-amorphous LRD-CPM mixtures. The results from XRPD and DSC confirmed the amorphous form of LRD in the co-amorphous solid dispersions. The FTIR results indicated that there was no intermolecular interaction between LRD, CPM, and PVP. In conclusion, the obtained LRD-CPM/PVP co-amorphous solid dispersions can successfully increase the water solubility and dissolution of LRD and extend the amorphous state of LRD without recrystallization.

A systematic review and meta-analysis of loratadine combined with montelukast for the treatment of allergic rhinitis

Background: Loratadine and montelukast are clinical first-line drugs in the treatment of allergic rhinitis (AR). However, there is no clear evidence of the efficacy of loratadine combined with montelukast in the treatment of AR. This study aimed to evaluate the efficacy and safety of the loratadine-montelukast combination on AR. Methods: In this meta-analysis, searches were conducted on PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and China National Knowledge Infrastructure (CNKI). The search terms included loratadine, montelukast, allergic rhinitis, and clinical trials. Meta-analyses were conducted using Rev Man 5.3 and Stata 15 statistical software. Results: A total of 23 studies with 4,902 participants were enrolled. For the primary outcome, pooled results showed that loratadine-montelukast can significantly reduce total nasal symptom scores (TNSS), when compared with loratadine (SMD, -1.00; 95% CI, -1.35 to -0.65, p < 0.00001), montelukast (SMD, -0.46; 95% CI, -0.68 to -0.25, p < 0.0001), or placebo (SMD, -0.93; 95% CI, -1.37 to -0.49, p < 0.00001). For secondary outcomes, pooled results showed that compared with loratadine, loratadine-montelukast can significantly improve nasal congestion, nasal itching, nasal sneezing, nasal rhinorrhea, and rhinoconjunctivitis quality of life questionnaires (RQLQ). Compared with montelukast, loratadine-montelukast can significantly improve nasal itching, and nasal sneezing. Compared with placebo, loratadine-montelukast can significantly improve nasal congestion, and RQLQ. Conclusion: Loratadine-montelukast combination is superior to loratadine monotherapy, montelukast monotherapy, or placebo in improving AR symptoms. Therefore, loratadine-montelukast combination can be an option for patients with moderate-severe AR or poorly response to monotherapy. Systematic review registration number: clinicaltrials.gov, identifier CRD42023397519.

The Combination Sorafenib-raloxifene-loratadine as a Novel Potential Therapeutic Approach Against Human Liver Cancer

BACKGROUND/AIM

Liver cancer is one of the malignancies with the highest mortality-to-incidence ratio worldwide. Therefore, novel therapeutic approaches are urgently needed. Combination therapy and drug repurposing can improve the response of the patients to therapy in several cancers. The aim of the present study was to merge these two strategies and evaluate whether the two-drug- or three-drug- combination of sorafenib, raloxifene, and loratadine improves the antineoplastic effect on human liver cancer cells in comparison to the single-drug effect.

MATERIALS AND METHODS

The human liver cancer cell lines HepG2 and HuH7 were studied. The effect of sorafenib, raloxifene, and loratadine on the metabolic activity was determined using the MTT assay. The inhibitory concentrations (IC₂₀ and IC₅₀) were calculated from these results and used in the drug-combination experiments. Apoptosis and cell survival were studied by flow cytometry and using the colony formation assay, respectively.

RESULTS

In both cell lines, sorafenib, raloxifene, and loratadine in two-drug and three-drug combinations significantly reduced metabolic activity and significantly increased the percentage of apoptotic cells compared to the single-drug effect. In addition, all the combinations significantly reduced the colony-forming capacity in the HepG2 cell line. Surprisingly, the effect of raloxifene on apoptosis was similar to that observed using the combinations.

CONCLUSION

The triple combination sorafenib-raloxifene-loratadine may be a novel promising approach in the treatment of liver cancer patients.

Combination of Cellulose Derivatives and Chitosan-Based Polymers to Investigate the Effect of Permeation Enhancers Added to In Situ Nasal Gels for the Controlled Release of Loratadine and Chlorpheniramine

The purpose of the study is to develop and assess mucoadhesive in situ nasal gel formulations of loratadine and chlorpheniramine maleate to advance the bioavailability of the drug as compared to its conventional dosage forms. The influence of various permeation enhancers, such as EDTA (0.2% w/v), sodium taurocholate (0.5% w/v), oleic acid (5% w/v), and Pluronic F 127 (10% w/v), on the nasal absorption of loratadine and chlorpheniramine from in situ nasal gels containing different polymeric combinations, such as hydroxypropyl methylcellulose, Carbopol 934, sodium carboxymethylcellulose, and chitosan, is studied. Among these permeation enhancers, sodium taurocholate, Pluronic F127 and oleic acid produced a noticeable increase in the loratadine in situ nasal gel flux compared with in situ nasal gels without permeation enhancer. However, EDTA increased the flux slightly, and in most cases, the increase was insignificant. However, in the case of chlorpheniramine maleate in situ nasal gels, the permeation enhancer oleic acid only showed a noticeable increase in flux. Sodium taurocholate and oleic acid seems to be a better and efficient enhancer, enhancing the flux > 5-fold compared with in situ nasal gels without permeation enhancer in loratadine in situ nasal gels. Pluronic F127 also showed a better permeation, increasing the effect by >2-fold in loratadine in situ nasal gels. In chlorpheniramine maleate in situ nasal gels with EDTA, sodium taurocholate and Pluronic F127 were equally effective, enhancing chlorpheniramine maleate permeation. Oleic acid has a better effect as permeation enhancer in chlorpheniramine maleate in situ nasal gels and showed a maximum permeation enhancement of >2-fold.

Preparation of Loratadine Orally Disintegrating Tablets by Semi-solid Extrusion 3D Printing

BACKGROUND

The orally disintegrating tablets (ODTs) are especially suitable for elders and children with dysphagia, who need to be given customized dosages.

OBJECTIVES

This study aimed to prepare orally disintegrating tablets (ODTs) which can be customized as drug content by using semi-solid 3D printing pressure extrusion technology, with water insoluble and thermally unstable drug loratadine.

METHODS

The influence of binder concentration, disintegrating agent dosage and ratio mannitol: cellulose on formability and disintegration time was investigated. The properties of orally disintegrating tablets were investigated by ATR-FTIR, XRPD, DSC and SEM. The correlation formula between tablet bottom area and drug content was established.

RESULTS

The formulation was optimized, and contained loratadine 3 g, cellulose 4 g, mannitol 2 g, carboxy methyl starch sodium 1g, 6% PVP K30 16 ml. The disintegration time was less than 60 s with infilling percentage of 60%, and the disintegration time was less than 30 s with infilling percentage of 40%. There was no detectable interaction between loratadine and the selected excipients by the analysis of ATR-FTIR, DSC and XRPD. The structure of the tablets was porous, and the drug was dissolved completely within 10 min. The drug content (x) of the tablet and the bottom area (y) of the tablet showed a linear fitting relationship, y = 3.8603x - 0.7176, r² = 0.9993.

CONCLUSION

Semi-solid extrusion of 3D printing technology was applied to prepare loratadine orally disintegrating tablets with customized drug content, which provides an alternative method for the research of customized preparation.

Effect of acupuncture at Xinwu acupoint combined with loratadine and fluticasone propionate on symptom alleviation, nasal function, and serum histamine level in patients with allergic rhinitis

OBJECTIVE

To determine the influence of acupuncture at the Xinwu acupoint combined with western medicine (loratadine and fluticasone propionate) on symptom alleviation, nasal mucociliary clearance velocity (MCV), and serum histamine level of patients with allergic rhinitis (AR).

METHODS

A total of 122 patients with AR treated in Gansu province hospital of TCM and The Third People's Hospital of Gansu Province from April 2019 to April 2021 were retrospectively analyzed. Among them, 54 patients treated with loratadine and fluticasone propionate were assigned to the control group, and 68 patients treated with additional acupuncture at the Xinwu acupoint based on treatment of the control group were assigned to the observation group. The treatment efficacy of the two groups was compared, and the scores of main symptoms and nasal function were also compared before and after therapy. Additionally, the two groups were compared in the levels of histamine, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and immunoglobulin E (IgE) before and after therapy.

RESULTS

After therapy, the observation group yielded a higher total effective rate than the control group (P=0.006) and had lower symptom scores than the control group (P<0.001). Additionally, the MCV of the two groups increased (P<0.001), and the nasal mucociliary transit time (MTT) and nasal resistance (NR) of both groups decreased (P<0.001) after therapy. The observation group showed a greatly better improvement of nasal function than the control group (P<0.001). Moreover, after therapy, the observation group showed lower histamine and IgE levels than the control group (P<0.01) and the observation group presented significantly lower levels than the control group, and had lower rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores than the control group (P<0.001). The two groups were not different in the incidence of adverse reactions (P=0.886).

CONCLUSION

Acupuncture at Xinwu acupoint combined with loratadine and fluticasone propionate can deliver a powerful efficacy on AR and alleviate the clinical symptoms, without increasing adverse reactions.

Effect of momethasone furoate combined with loratadine and montelukast sodium on inflammatory factors and pulmonary function in children with allergic rhinitis

OBJECTIVE

To compare the effects of mometasone furoate in combination with loratadine and montelukast sodium on inflammatory factors and pulmonary function in children with allergic rhinitis (AR).

METHODS

In this retrospective study, a total of 89 children with AR admitted to our hospital from March 2020 to October 2021 were enrolled. Among them, 47 children who received mometasone furoate combined with loratadine were designated group A, while the other 42 with mometasone furoate combined with montelukast sodium were group B. The clinical efficacy of both groups was compared, and the levels of inflammatory factors IL-6 and TNF-α as well as the changes of pulmonary function levels were tested during the treatment. Adverse reactions during treatment were recorded. Finally, children were followed up for 3 months to record rhinitis recurrence after discontinuation of the treatment.

RESULTS

There was no statistical difference in clinical treatment efficacy between both groups (P>0.05), while the levels of IL-6, TNF-α, and IgE were lower in children in group A than in group B at 2 weeks of treatment. Group A's lung function indexes, including forced expiratory volume in one second (FEV1%), forced expiratory volume in one second/forced vital capacity (FEV1/FVC) and peak expiratory flow (PEF), were higher than in group B (all P<0.05). The total incidence of adverse reactions was dramatically lower in group A than group B (P<0.05). Follow-up demonstrated no difference in the recurrence rate of rhinitis between both groups of children (P>0.05). Higher TNF-α after treatment, history of allergy, family history of rhinitis, combined asthma, and parental history of smoking were independent risk factors for relapse after discontinuation of the drug in children.

CONCLUSION

Both mometasone furoate combined with either loratadine or montelukast sodium had good effects in AR, while the first option had a faster inhibitory effect on inflammatory factors and a better protection of lung function in children.

Simultaneous Determination of Loratadine and Its Metabolite Desloratadine in Beagle Plasma by LC-MS/MS and Application for Pharmacokinetics Study of Loratadine Tablets and Omeprazole‑Induced Drug-Drug Interaction

Background

Loratadine (LTD) is a Biopharmaceutical Classification System II basic drug with pH-sensitive aqueous solubility and dissolution is a speed-limiting step of its absorption. The drug dissolution and the gastrointestinal tract pH conditions are likely to influence the in vivo pharmacokinetic behavior of LTD tablets.

Materials and Method

A rapid, sensitive, and reliable bioanalytical method for simultaneous quantitation of LTD and its active metabolite desloratadine (DL) in beagle plasma was developed and validated based on liquid chromatography tandem mass spectrometry (LC-MS/MS). Sample preparation in low plasma consumption was accomplished by liquid–liquid extraction. The chromatographic separation was achieved on a Phenomenex Kinetex C8 column using acetonitrile and 5 mM ammonium formate as the mobile phase. A comparative pharmacokinetics study of three LTD tablets with different dissolution rates was conducted in male beagles in fasting state and an omeprazole-induced drug–drug interaction (DDI) study was subsequently performed under pretreatment of omeprazole.

Results and Conclusion

The method showed a good linear correlation over the concentration ranges of 0.008–24 ng/mL for LTD and 0.8–800 ng/mL for DL, and was successfully applied to analyze the two compounds in beagle plasma. Pharmacokinetic results showed in the fasting state the three LTD tablets were equivalent in beagles in terms of effective components. DL of the three tablets were equivalent, indicating metabolite was less susceptible to pharmaceutic preparation factors for LTD tablets in beagles. Moreover, significant changes in LTD and DL pharmacokinetics parameters were observed under the effect of omeprazole-induced pH increase in gastrointestinal tract, suggesting that DDI effects are of concern for the curative effect of LTD when combined with omeprazole. The findings will contribute to the future pharmaceutical preparations research as well as the clinical application of LTD.

Nanosized-Loratadine Embedded Orodispersible Films for Enhanced Bioavailability: Scalable Preparations and Characterizations

The patient-centric strategy urges the pharmaceutical companies to develop orodispersible films (ODF) as a new approach for pediatrics. However, the most common ODF-fabricated method, solvent casting, is facing the safety challenges of safety during manufacturing. To obtain favorable formulations with the ease of use and rapid dissolution, nanotechnology has been accounted for the development process. In this work, we investigated the wet-milling technique in preparing nanocarriers for loratadine-a hydrophobic anti-histamine drug. The results showed that the wet-milling technique could produce nanocarriers at the size of 400 nm. The reduction of particle size induced the increase of solubility and the dissolution rate of loratadine. Moreover, the pre-formulation of nanosized materials could adapt to the preparation of orodispersible films that disintegrated (less than 60s) and dissolved quickly. The DSC results showed that after the milling process, the crystallinity of loratadine was unchanged; however, the reduction in size induced an enhancement of drug bioavailability. After orally administrated to rats, the drug was quickly reached to the blood circulation, just after 30 min. C_max increased from 44.97 ng/mL for the raw drug to 101.02 ng/mL for the nanocrystal leading to an enhancement of the AUC_0-24h by 5.69-fold when the nanocrystal ODF was administrated. The ease of formulation and the improvement of drug solubility as well as bioavailability potentiated orodispersible films as a promising drug delivery for loratadine. Graphical abstract.

Computational and Experimental Models of Type III Lipid-Based Formulations of Loratadine Containing Complex Nonionic Surfactants

Type III lipid-based formulations (LBFs) combine poorly water-soluble drugs with oils, surfactants, and cosolvents to deliver the drugs into the systemic circulation. However, the solubility of the drug can be influenced by the colloidal phases formed in the gastrointestinal tract as the formulation is dispersed and makes contact with bile and other materials present within the GI tract. Thus, an understanding of the phase behavior of LBFs in the gut is critical for designing efficient LBFs. Molecular dynamics (MD) simulation is a powerful tool for the study of colloidal systems. In this study, we modeled the internal structures of five type III LBFs of loratadine containing poly(ethylene oxide) nonionic surfactants polysorbate 80 and polyoxyl hydrogenated castor oil (Kolliphor RH40) using long-timescale MD simulations (0.4-1.7 μs). We also conducted experimental investigations (dilution of formulations with water) including commercial Claritin liquid softgel capsules. The simulations show that LBFs form continuous phase, water-swollen reverse micelles, and bicontinuous and phase-separated systems at different dilutions, which correlate with the experimental observations. This study supports the use of MD simulation as a predictive tool to determine the fate of LBFs composed of medium-chain lipids, polyethylene oxide surfactants, and polymers.

Loratadine vs Rupatadine: Unearthing the Capital Choice in Chronic Idiopathic Urticaria (CIU) - A Randomized Controlled Trial

Background:

Chronic Idiopathic Urticaria (CIU) is a debilitating disease characterised by almost daily presence of urticarial symptoms like short-lived wheals, itching, and erythema for at least 6 weeks without an identifiable cause there by leading to impairment of quality of life of the patient.

Aim:

To evaluate the efficacy and safety of loratadine and rupatadine in chronic idiopathic urticaria.

Methods:

This is a prospective, randomized, single-blind, parallel arm study conducted to evaluate the efficacy and safety of loratadine and rupatadine in patients with CIU. The study was registered prospectively with Clinical Trial registry of India (CTRI/2017/05/008624). Institutional Ethics Committee clearance was obtained. Written informed consent was obtained from all the participants before enrolment into the trial. The study was conducted in the outpatient department of Dermatology, SRM Medical College, Kattankulathur, Tamil Nadu, India, during the period from June 2017 to August 2018. Patients with CIU enrolled into the study based on inclusion-exclusion criteria were given the intervention drugs; Loratadine 10 mg once daily or rupatadine10 mg once daily orally for 6 weeks.

Results:

Rupatadine is more efficacious than loratadine in the reduction of Total Leucocyte Count, Differential Count and Absolute Eosinophil Count, the key determinants of allergy. Rupatadine also produced better improvement in Total symptom Score, Dermatology Life Quality Index in patients with CIU.

Conclusion:

Analysis of all the parameters of efficacy and safety establishes the probable superiority of rupatadine over loratadine for the treatment of urticaria.

Preparation and Characterization of Mucoadhesive Loratadine Nanoliposomes for Intranasal Administration

Objectives

The present study aimed to formulate and characterize mucoadhesive liposomes for intranasal delivery of loratadine. In particular, the formulation was aimed to improve the drug bioavailability and efficacy.

Materials and Methods

Liposomes were prepared by thin-film hydration method, with soybean phosphatidylcholine and cholesterol as main components. Liposomes were coated with chitosan solution at a concentration of 0.05% and 0.1%, w/v. The formulations were assessed for particle size, polydispersity index (PDI), encapsulation efficiency (EE), thermodynamic behavior, in vitro drug release, mucoadhesiveness, and stability.

Results

Particle size analysis showed that the vesicles of uncoated and coated liposomes with 0.05% and 0.1% chitosan were characterized by size of 193±3.3 nm, 345±4.6, and 438±7.3 nm, respectively. Size distribution for developed formulations was in the acceptable range (PDI <0.7). EE was recorded to be approximately 80%. Chitosan-coated liposomes demonstrated slower release rate as compared to uncoated liposomes. Drug release kinetics profile for all the formulations followed a zero-order model. Chitosan coating improved mucoadhesiveness by more than 3-fold as compared to uncoated liposomes. However, no significant differences were recorded between mucin adsorption behavior of 0.05% and 0.1% chitosan-coated liposomes (p>0.05). For stability studies, liposomes were stored at 4°C for 3 months, and changes in particle diameter, PDI, and EE % were recorded. No significant alternations were reported in particles size, PDI, and drug leakage of coated liposomes.

Conclusion

Liposomes coated with 0.05% chitosan were chosen as the optimum formulation, which demonstrated a significant potential for overcoming the nasal drug delivery limits for short residence time and mucociliary clearance.

Cocrystal formation of loratadine-succinic acid and its improved solubility

OBJECTIVES

Loratadine belongs to Class II compound of biopharmaceutics classification system (BCS) due its low solubility and high membrane permeability. Cocrystal is a system of multicomponent crystalline that mostly employed to improve solubility. Succinic acid is one of common coformer in cocrystal modification. This research aims to investigate cocrystal formation between loratadine and succinic acid and its effect on solubility property of loratadine.

METHODS

Cocrystal of loratadine-succinic acid was prepared by solution method using methanol as the solvent. Cocrystal formation was identified under observation of polarization microscope and analysis of the binary phase diagram. The cocrystal phase was characterized by differential thermal analysis (DTA), powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). Solubility study was conducted in phosphate-citrate buffer pH 7.0 ± 0.5 at 30 ± 0.5 °C.

RESULTS

Loratadine is known to form cocrystal with succinic acid in 1:1 M ratio. Cocrystal phase has lower melting point at 110.9 °C. Powder diffractograms exhibited new diffraction peaks at 2θ of 5.28, 10.09, 12.06, 15.74, 21.89, and 28.59° for cocrystal phase. IR spectra showed that there was a shift in C=O and O-H vibration, indicating intermolecular hydrogen bond between loratadine and succinic acid. SEM microphotographs showed different morphology for cocrystal phase. Loratadine solubility in cocrystal phase was increased up to 2-fold compared to loratadine alone.

CONCLUSIONS

Cocrystal of loratadine and succinic acid is formed by stoichiometry of 1:1 via C=O and H-O interaction. Cocrystal phase shows different physicochemical properties and responding to those properties, it shows improved loratadine solubility as well.

An Allergic Risk Factor Analysis of Extraordinary Daytime Only Urinary Frequency in Children

Objective

This study aims to investigate the risk factors of extraordinary daytime only urinary frequency (EDOUF) and propose a form of clinical treatment.

Methods

Correlation and binary logistic regression analyses were carried out on the medical records of children with EDOUF, including their history of eczema, urticaria, allergic rhinitis or allergic cough, and pruritus (eye rubbing, etc.).

Results

A total of 266 children with EDOUF, 127 boys and 139 girls, were enrolled in the present study; their average age was 5.60 ± 2.04 years. Binary logistic regression analysis revealed that the risk factors of EDOUF in children were eczema (odds ratio [OR] = 8.393), allergic rhinitis or allergic cough (OR = 4.459), pruritus (eye rubbing, etc.; OR = 3.879), and elevated total serum IgE level (OR = 7.927). The efficacy rate of oral administration of antihistamine (desloratadine) was 89.1%.

Conclusion

Systemic or local allergic conditions, such as eczema, allergic rhinitis or allergic cough, and pruritus (including eye rubbing), and elevated total serum IgE level, are risk factors for the occurrence of EDOUF in children. The oral administration of antihistamine (desloratadine) can alleviate the symptoms.

Clinical efficacy of jade wind-barrier powder combined with loratadine in the treatment of pediatric allergic rhinitis

OBJECTIVE

To investigate the clinical efficacy of Jade Wind-Barrier Powder combined with Loratadine in the treatment of pediatric allergic rhinitis (PAR).

METHODS

The clinical data of 101 children with allergic rhinitis (AR) admitted to the Affiliated Hospital of Qingdao University and Affiliated Hospital of Nanjing University of Traditional Chinese Medicine from January 2019 to December 2019 were retrospectively analyzed. The children were randomly divided into Group A (n=50) and Group B (n=51) in accordance with a random number table. Group A was treated with Loratadine only, while Group B was treated with Loratadine combined with Jade Wind-Barrier powder. The clinical efficacy, symptom disappearance time, symptom scores before and after treatment, indices of immunological function, changes in the indices of inflammatory factors and disease recurrence were compared between the two groups.

RESULTS

The overall response rate (ORR) in Group B (96.08%) was higher than that in Group A (76.00%) (P < 0.05). The disappearance time of sneezing, stuffy nose, runny nose and itchy nose in Group B was shorter than that in Group A (P < 0.05). After treatment, Group B exhibited lower symptom scores for sneezing, stuffy nose, runny nose and itchy nose, lower levels of IL-13, IL-4 and TNF-α, and higher CD4⁺CD25⁺, CD19⁺ and CD8⁺ than Group A (P < 0.05). The recurrence rate in Group B (3.92%) was lower than that in Group A (26.00%) (P < 0.05).

CONCLUSION

Jade Wind-Barrier powder combined with Loratadine can improve clinical symptoms, immunity, inflammation levels and disease recurrence rate of PAR patients, with a significant clinical efficacy.

On the binding reaction of loratadine with human serum acute phase protein alpha 1-acid glycoprotein

Loratadine is an important anti-allergic drug. It is a second generation antihistamine drug used to treat allergic rhinitis, hay fever and urticaria. Human serum alpha 1-acid glycoprotein (AG) is an important acute phase protein and its serum concentration is found to increase in inflammation and acute response.The binding interaction between loratadine and AG is studied using spectroscopy and molecular docking techniques. The results obtained from fluorescence quenching experiments demonstrated that the fluorescence intensity of AG is quenched by loratadine. Loratadine was found to bind AG with the binding constant of ≈10⁴ at 298 K. The Gibb's free energy change was found to be negative for the interaction of loratadine with AG indicating the binding process is spontaneous. Binding of loratadine with AG induced ordered structures in the protein. Hydrogen bonding and hydrophobic interactions were the main bonding forces between AG-loratadine as revealed by molecular docking results. This study suggests the importance of binding of anti-allergic drug to AG spatially in the diseases where the plasma concentration of AG increases many folds and interaction with this protein becomes significant. This study will help in design of drug dosage and adjustment accordingly to achieve optimal treatment outcome. Communicated by Ramaswamy H. Sarma.

Preparation of loratadine nanocrystal tablets to improve the solubility and dissolution for enhanced oral bioavailability

OBJECTIVES

Loratadine is a selective H1 receptor inhibitor that has been widely used in the clinical treatment of allergic diseases. Here we aimed to develop a novel solid loratadine nanocrystal to increase the low and pH-dependent water solubility for bioavailability enhancement.

METHODS

Loratadine solid nanocrystal was developed through high-speed shear-high pressure homogenization followed by freeze-drying, which was further prepared into tablets through direct compression. The formulation and process parameter were screened. Furthermore, the characterization and oral bioavailability of loratadine nanocrystal were studied.

KEY FINDINGS

The loratadine nanocrystal had the satisfactory particle size of 425.9 nm and great redispersibility, which was mainly attributed to the addition of Pluronic F127 and polyvinylpyrrolidone K17 as the stabilizer. The saturation solubility of the loratadine nanocrystal was increased to 3.81, 3.22 and 2.57-fold that of the crude drug in water, pH 6.8 and pH 4.5 buffer respectively. Furthermore, the pharmacokinetic studies in rats revealed that the AUC (0-∞) of the nanocrystal tablets was 2.38-fold that of raw tablets and 1.94-fold that of commercial tablets, respectively.

CONCLUSIONS

The nanocrystal tablets could significantly improve the oral bioavailability of loratadine, which would also be a promising approach to enhance the solubility of insoluble drugs.

Drug Content Uniformity: Quantifying Loratadine in Tablets Using a Created Raman Excipient Spectrum

Raman spectroscopy has proven valuable for determining the composition of manufactured drug products, as well as identifying counterfeit drugs. Here we present a simple method to determine the active pharmaceutical ingredient (API) mass percent in a sample that does not require knowledge of the identities or relative mass percents of the inactive pharmaceutical ingredients (excipients). And further, we demonstrated the ability of the method to pass or fail a manufactured drug product batch based on a calculated acceptance value in accordance with the US Pharmacopeia method for content uniformity. The method was developed by fitting the Raman spectra of 30 Claritin^® tablets with weighted percentages of the Raman spectrum of its API, loratadine, and a composite spectrum of the known excipients. The mean loratadine mass of 9.79 ± 40 mg per 100 mg tablet compared favorably to the 10.21 ± 0.63 mg per 100 mg tablet determined using high-performance liquid chromatography, both of which met the acceptance value to pass the 10 mg API product as labelled. The method was then applied to a generic version of the Claritin product that employed different excipients of unknown mass percents. A Raman spectrum representative of all excipients was created by subtracting the API Raman spectrum from the product spectrum. The Raman spectra of the 30 generic tablets were then fit with weighted percents of the pure loratadine spectrum and the created excipient spectrum, and used to determine a mean API mass for the tablets of 10.12 ± 40 mg, again meeting the acceptance value for the 10 mg API product. The data suggest that this simple method could be used to pass or fail manufactured drug product batches in accordance with the US Pharmacopeia method for content uniformity, without knowledge of the excipients.

Loratadine Alleviates Advanced Glycation End Product-Induced Activation of NLRP3 Inflammasome in Human Chondrocytes

Background

Chondrocytes in joint tissue are responsible for the synthesis and degradation of the cartilage matrix. Chondrocytes have been closely linked to the pathogenesis of osteoarthritis and cartilage damage. Targeted drug intervention directed at chondrocyte function is a promising strategy for the treatment of osteoarthritis. The effects of histamine receptor H1 (H1R) and its antagonist loratadine in osteoarthritic chondrocytes are less known.

Materials and Methods

The inhibitory effects of loratadine on NLRP3 inflammasome and the NADPH oxidase subunit NOX4 were assessed in advanced glycation end products (AGEs)-treated SW1353 chondrocytes by real-time PCR, ELISA, and Western blot experiments. The mitochondrial ROS level was measured using the specific probe MitoSOX Red. The dependent effect of loratadine on the transcriptional factor nuclear factor erythroid 2-related factor 2 (NRF2) was evaluated through an oligo-based siRNA knockdown approach and Western blot analysis.

Results

The expression of H1R was dose-responsively induced by AGEs in chondrocytes. Treatment with loratadine mitigated AGEs-induced oxidative stress, as revealed by suppressed production of mitochondrial ROS and the NADPH oxidase subunit NOX4. Loratadine treatment inhibited the expression of TxNIP and several components of the NLRP3 inflammasome complex, including NLRP3, ASC, and cleaved caspase 1 (P10). Moreover, loratadine suppressed the expression of NRF2, and the silencing of NRF2 abolished the suppressive effect of loratadine on NLRP3 inflammasome activation.

Conclusion

Our study demonstrates that loratadine protects chondrocytes from AGEs-induced TxNIP/NLRP3 inflammasome activation by modulating the expression of the transcriptional factor NRF2. This finding implies that loratadine has therapeutic potential in the treatment of osteoarthritis and cartilage injury.

Effects of Oral Antihistamines on Tear Volume, Tear Stability, and Intraocular Pressure

The goal of this study was to investigate the effects of two commonly used oral antihistamines—diphenhydramine and loratadine—on tear volume, tear breakup time, and intraocular pressure. Placebo, diphenhydramine, and loratadine were administered for one week to 33 subjects experimentally blind to the treatment given. All the subjects received all three treatments over a period of six weeks. The outcome measures were the change in phenol red thread test (PRT), the tear breakup time (TBUT), and the intraocular pressure (IOP) of both eyes evaluated by experimentally masked observers. Neither of the mean changes in TBUT or IOP depended on the treatment given, but there was a significant monocular decrease in tear volume from diphenhydramine use. While we used an adequate treatment washout period of seven days, our investigation was limited by the short treatment times and inclusion of only young healthy patients. Overall, however, these results suggest that systemic diphenhydramine use should be limited to increase the effectiveness of conventional therapies. Clinicians should have fewer reservations about recommending the use of loratadine concurrent with dry eye treatments.

Technology of Orodispersible Polymer Films with Micronized Loratadine-Influence of Different Drug Loadings on Film Properties

The production of orodispersible films (ODFs) with suspended insoluble drug substances is still a challenge, mainly due to the difficulty associated with achieving a proper homogeneity and mechanical properties of the films. Hypromellose (HPMC) and a mixture of polyvinyl alcohol (AP) and povidone (PVP) were compared in terms of their suitability for ODFs incorporating suspended micronized loratadine (LO) in a concentration range of 10%–40%. In a planetary mixer (Thinky), a uniform dispersion of LO in an aqueous viscous casting solution was obtained. The suspended LO particles caused dose-dependent changes in the viscosity of the casting mass and affected the mechanical quality of ODFs. Drug concentrations higher than 30% reduced the film flexibility and tear resistance, depending on the polymer type. LO films with a thickness of 100 µm disintegrated within 60-100 s, with no significant influence of the LO content in the range 10%–30%. HPMC films, regardless of the drug concentration, met the pharmacopoeial requirements regarding the uniformity of the drug content. AP/PVP films were too elastic, and the drug content uniformity was not achieved. The conclusion is that, using an HPMC matrix, it is possible to obtain a high load of a poorly water-soluble drug (30% of dry film mass corresponds to a dose of 5 mg per 1.5 cm²) in ODFs characterized by proper physical characteristics.

Developing a High-performance Liquid Chromatography Method for Simultaneous Determination of Loratadine and its Metabolite Desloratadine in Human Plasma

BACKGROUND

Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma.

METHODS

The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm.

RESULTS

The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma.

CONCLUSION

The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.

Hepatocyte spheroids as a viable in vitro model for recapitulation of complex in vivo metabolism pathways of loratadine in humans

Accurate prediction of in vivo metabolic pathways in humans can be challenging because in vitro liver matrices may fail to produce certain in vivo metabolites.Rat and human spheroids, generated from cryopreserved hepatocytes in media that contained minimal amount of serum, maintained morphology, viability and cytochrome P450 (CYP) activities for at least a week without media exchange.With spheroid cultures, multiple Phase I and Phase II metabolites were observed in rat and human spheroid cultures that were incubated with loratadine (LOR) for multiple days. Consistent with in vivo observations, 3-hydroxydesloratadine, (3-OH-DL), along with its glucuronide, were observed in human spheroids, but not in rat spheroids. Interestingly, the putative intermediate metabolite leading to 3-OH-DL, DL-N-glucuronide, was observed in incubations with both rat and human spheroids. In conclusion, hepatocyte spheroid were capable of recapitulating the inter-species differences in metabolism between human and rat for LOR, therefore, it may represent a viable model for studying complex metabolic pathways.

Effects of loratadine, a histamine H1 receptor antagonist, on the skeletal system of young male rats

Background

Histamine H₁ receptor antagonists are widely used in the treatment of allergic diseases. H₁ receptors are expressed on bone cells and histamine takes part in regulation of bone metabolism. Loratadine is often prescribed to children.

Purpose

The aim of the present study was to investigate the effects of loratadine on the skeletal system of young rats.

Material and methods

Loratadine (0.5, 5, and 50 mg/kg p.o. daily) was administered for 4 weeks to male Wistar rats, 6-week-old at the start of the experiment. Bone mass, mass of bone mineral, calcium, and phosphorus content in the bone mineral of the tibia, femur, and L-4 vertebra, histomorphometric parameters of the femur, mechanical properties of the proximal tibial metaphysis, femoral diaphysis and femoral neck, and serum levels of bone turnover markers were examined.

Results

Loratadine at 0.5 and 5 mg/kg did not significantly affect the skeletal system of young rats. At 50 mg/kg, loratadine decreased the femoral length, increased content of calcium and phosphorus in the bone mineral of the vertebra, and tended to improve mechanical properties of the tibial metaphysis.

Conclusion

High-dose loratadine slightly but significantly affected development of the skeletal system in rapidly growing rats.

Clinical efficacy of montelukast sodium combined with budesonide or combined with loratadine in treating children with cough variant asthma and influence on inflammatory factors in the serum

Clinical efficacy of montelukast sodium combined with budesonide or combined with loratadine in children with cough variant asthma was investigated. A retrospective analysis of the medical records of 72 children with cough variant asthma who were treated in Xuzhou Children's Hospital, Xuzhou Medical University from April 2015 to August 2017 was performed and the 72 child patients were divided into two groups: 35 children were treated with montelukast sodium combined with budesonide in Group A, and 37 children were treated with montelukast sodium combined with loratadine in Group B. The clinical efficacy of the two groups was evaluated according to the lung function indexes [forced expiratory volume in the first second (FEV1), ratio of the forced expiratory volume in the first second to the forced vital capacity (FEV1/FVC), the peak expiratory flow (PEF)], the inflammation biomarkers [tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4)], the level of eosinophil granulocyte, and the level of IgE at three time-points: before treatment, the 4th week after treatment, and the 12th week after treatment as well as adverse reactions, recurrence of symptoms, and treatment compliance were recorded. After treatment, the levels of FEV1, FEV1/FVC, PEF, TNF-α and IL-4, eosinophil granulocyte and IgE in the two groups were significantly improved (P<0.05). The treatment compliance of Group A was significantly lower than that of Group B (P<0.05). In conclusion, the method of montelukast sodium combined with budesonide or loratadine are both worthy of clinical promotion because they have equivalent efficacy in the treatment of cough variant asthma to effectively improve the lung function and inflammatory response in patients and both bring less adverse reactions and lower recurrence rate.

The combination of loratadine with famotidine to relieve the symptoms of urinary frequency in female patients with bladder function disorders：First report of three cases

WHAT IS KNOWN AND OBJECTIVES

Urinary frequency is a common presentation of bladder function disorders in female patients. Few medicines are effective in all patients. The use of loratadine combined with famotidine had not been previously reported for this indication.

CASE DESCRIPTION

Three female patients complaining of urinary frequency had been given loratadine at 10 mg QD combined with famotidine 20 mg BID for about 5 months. They all achieved symptom improvement.

WHAT IS NEW AND CONCLUSION

The combination of loratadine with famotidine was used to treat urinary frequency. It was safe, effective, and convenient, and may be an option for oral medical therapy in female patients with bladder function disorders.

Transient Expression of Human Cytochrome P450s 2D6 and 3A4 in Nicotiana benthamiana Provides a Possibility for Rapid Substrate Testing and Production of Novel Compounds

Employment of transient expression of foreign genes for bioconversion of pharmaceutically valuable low-molecular-weight compounds, including plant secondary metabolites, is an enticing trend still scantily explored in plant biotechnology. In the present work, an efficient protocol for rapid assessment of synthetic and plant-derived metabolites as potential substrates for human P450s (CYP2D6 and CYP3A4) via Agrobacterium-mediated transient expression in Nicotiana benthamiana is put forth. Animal P450s with broad substrate specificity are promising candidates for transformation of diverse metabolites. The efficiency of P450s in heterologous surroundings is not always satisfactory and depends on the availability of an associated electron-transfer enzyme. Plants represent an attractive assortment of prospective hosts for foreign P450s expression. The optimal composition of genetic blocks providing the highest transient expression efficiency is designed, an effective substrate administration scheme is validated, and biological activity of the investigated P450s against loratadine and several indole alkaloids with different molecular scaffold structures is tested. A novel indole alkaloid, 11-hydroxycorynanthine, is isolated from N. benthamiana plants transiently expressing CYP2D6 and supplemented with corynanthine, and its structure was elucidated. The proposed technique might be of value in realization of combinatorial biosynthesis concept comprising the junction of heterologous enzymes and substrates in different metabolic surroundings.

[Effect of nasal glucocorticoid combined with loratadine or montelukast on allergic rhinitis]

Objective:To evaluate the effect of nasal glucocorticoid combined with second-generation antihistamines or leukotriene receptor antagonists on the treatment of moderate severe allergic rhinitis, and explore the optimal scheme of personalized treatment for AR patients.Method:Fiftyseven patients with persistent moderatesevere allergic rhinitis were randomly divided into three groups and treated by mometasone furoate aqueous nasal spray (group MOM), mometasone furoate aqueous nasal spray combined with loratadine (group MOM+L), mometasone furoate aqueous nasal spray combined with montelukast (group MOM+M) for 4 weeks. Four major clinical symptoms of allergic rhinitis: nasal congestion, nose itching, sneezing and runny nose were evaluated by "symptom rating score" before treatment and after treatment for 4 weeks.Result:After treatment, the total nasal symptom scores of each group showed a decreasing tendency, and the differences between various time points were statistically significant (P< 0.05). For the symptom of nasal congestion, the symptom score of MOM+M group was significantly lower than that of MOM group and MOM+L group at the 2nd and 4th week after treatment. For the symptoms of sneezing and nasal itching, MOM+L group had the lowest score at each time point after treatment and the difference was statistically significant compared with MOM group (P< 0.05), but there was no significant difference between MOM group and MOM+M group (P> 0.05). For the symptom of runny nose, the score of MOM+L group was significantly lower than MOM group (P< 0.05) at the 1st and 2nd week, MOM+M group was significantly lower than MOM group (P< 0.05) at the 2nd and 4th week, while there was no significant difference between MOM+L group and MOM+M group (P> 0.05).Conclusion:Nasal glucocorticoid alone or combined with secondgeneration antihistamines or leukotriene receptor antagonists can effectively control nasal symptoms of moderatesevere allergic rhinitis, yet the effect of combination therapy is better. For nasal congestion, nasal glucocorticoid combined with leukotriene receptor antagonists have a better effect. For nasal itching and sneezing, the choice of nasal glucocorticoid combined with second-generation antihistamines may be more sensible. For runny nose, nasal glucocorticoid combined with second-generation antihistamines or leukotriene receptor antagonists have similar efficacy.

HPLC-high-resolution mass spectrometry with polarity switching for increasing throughput of human in vitro cocktail drug-drug interaction assay

AIM

Evaluation of HPLC-high-resolution mass spectrometry (HPLC-HRMS) full scan with polarity switching for increasing throughput of human in vitro cocktail drug-drug interaction assay.

MATERIALS & METHODS

Microsomal incubates were analyzed using a high resolution and high mass accuracy Q-Exactive mass spectrometer to collect integrated qualitative and quantitative (qual/quant) data.

RESULTS

Within assay, positive-to-negative polarity switching HPLC-HRMS method allowed quantification of eight and two probe compounds in the positive and negative ionization modes, respectively, while monitoring for LOR and its metabolites.

CONCLUSION

LOR-inhibited CYP2C19 and showed higher activity for CYP2D6, CYP2E1 and CYP3A4. Overall, LC-HRMS-based nontargeted full scan quantitation allowed to improve the throughput of the in vitro cocktail drug-drug interaction assay.

Study of Statin- and Loratadine-Induced Muscle Pain Mechanisms Using Human Skeletal Muscle Cells

Many drugs can cause unexpected muscle disorders, often necessitating the cessation of an effective medication. Inhibition of monocarboxylate transporters (MCTs) may potentially lead to perturbation of l-lactic acid homeostasis and muscular toxicity. Previous studies have shown that statins and loratadine have the potential to inhibit l-lactic acid efflux by MCTs (MCT1 and 4). The main objective of this study was to confirm the inhibitory potentials of atorvastatin, simvastatin (acid and lactone forms), rosuvastatin, and loratadine on l-lactic acid transport using primary human skeletal muscle cells (SkMC). Loratadine (IC₅₀ 31 and 15 µM) and atorvastatin (IC₅₀ ~130 and 210 µM) demonstrated the greatest potency for inhibition of l-lactic acid efflux at pH 7.0 and 7.4, respectively (~2.5-fold l-lactic acid intracellular accumulation). Simvastatin acid exhibited weak inhibitory potency on l-lactic acid efflux with an intracellular lactic acid increase of 25–35%. No l-lactic acid efflux inhibition was observed for simvastatin lactone or rosuvastatin. Pretreatment studies showed no change in inhibitory potential and did not affect lactic acid transport for all tested drugs. In conclusion, we have demonstrated that loratadine and atorvastatin can inhibit the efflux transport of l-lactic acid in SkMC. Inhibition of l-lactic acid efflux may cause an accumulation of intracellular l-lactic acid leading to the reported drug-induced myotoxicity.

Coamorphous Loratadine-Citric Acid System with Enhanced Physical Stability and Bioavailability

Coamorphous systems using citric acid as a small molecular excipient were studied for improving physical stability and bioavailability of loratadine, a BCS class II drug with low water solubility and high permeability. Coamorphous loratadine-citric acid systems were prepared by solvent evaporation technique and characterized by differential scanning calorimetry, X-ray powder diffraction, and Fourier transform infrared spectroscopy. Solid-state analysis proofed that coamorphous loratadine-citric acid system (1:1) was amorphous and homogeneous, had a higher T _g over amorphous loratadine, and the intermolecular hydrogen bond interactions between loratadine and citric acid exist. The solubility and dissolution of coamorphous loratadine-citric acid system (1:1) were found to be significantly greater than those of crystalline and amorphous form. The pharmacokinetic study in rats proved that coamorphous loratadine-citric acid system (1:1) could significantly improve absorption and bioavailability of loratadine. Coamorphous loratadine-citric acid system (1:1) showed excellently physical stability over a period of 3 months at 25°C under 0% RH and 25°C under 60% RH conditions. The improved stability of coamorphous loratadine-citric acid system (1:1) could be related to an elevated T _g over amorphous form and the intermolecular hydrogen bond interactions between loratadine and citric acid. These studies demonstrate that the developed coamorphous loratadine-citric acid system might be a promising oral formulation for improving solubility and bioavailability of loratadine.

Combining thioridazine and loratadine for the treatment of gastrointestinal tumor

In 2015, the American Society of Clinical Oncology announced that strategies of using combination therapies have been indicated to be effective against many types of cancer. In the present study, thioridazine (THZ) was used in a combination therapy with loratadine (LOR) to target gastrointestinal tumor, with the aim of investigating whether combined therapy was superior to monotherapy in its antitumor effects. The antiproliferative effects on CT26.WT and MFC cells were analyzed using cell-counting kit-8 assay, and synergistic effect was assessed by combination index (Fig. 1). Annexin V and propidium iodide staining indicated the combination therapy was able to induce apoptosis and that this may be mediated via caspase-3, -9 and poly (ADP-ribose) polymerase (PARP) (Fig. 2). Antitumor activity was also evaluated in CT26.WT xenografts in BALB/c mice (Fig. 3). Furthermore, as expected, combination therapy was able to successfully inhibit the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin signaling pathway (Fig. 4). These findings suggest that the combination therapy with THZ and LOR may provide a promising therapy for gastrointestinal cancer.

When Hydromorphone Is Not Working, Try Loratadine: An Emergency Department Case of Loratadine as Abortive Therapy for Severe Pegfilgrastim-Induced Bone Pain

BACKGROUND

Intractable bone pain is a notorious adverse effect of granulocyte-colony stimulating factors (G-CSFs), such as pegfilgrastim and filgrastim, which are given to help prevent neutropenia in patients who are undergoing chemotherapy. G-CSF-induced bone pain is surprisingly common and often refractory to treatment with conventional analgesics.

CASE REPORT

This article describes an emergency department case of opiate and nonsteroidal anti-inflammatory drug-resistant pegfilgrastim-induced bone pain that was successfully alleviated with 10 mg of oral loratadine, allowing for discharge home. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case suggests that loratadine may be an easy to implement, safe, and effective therapy in the emergency department management of intractable bone pain caused by G-CSF use. Emergency physicians should be aware that loratadine may successfully relieve otherwise intractable G-CSF-induced bone pain and allow for discharge home.

Dissolution evaluation in vitro and bioavailability in vivo of self-microemulsifying drug delivery systems for pH-sensitive drug loratadine

The aim of this study was to improve the oral absorption of loratadine, a pH-sensitive drug, by self-microemulsifying drug delivery systems (SMEDDSs). The optimal SMEDDS was analysed and evaluated after emulsification in distilled water with diameter of 26.57 ± 0.71 nm and zeta potential of -30.5 ± 4.5 mV. Dissolution experiments in vitro were carried out in different released media of pH values and the SMEDDS formulations were able to release loratadine completely in different media while market tablets just performed similarly in the media of pH 1.2. Furthermore, the oral bioavailability and the pharmacokinetic behaviour of loratadine formulations in vivo were studied after a single dose of 1 mg/kg loratadine in beagle dogs. The SMEDDS formulations displayed higher Cmax and AUC, approximately 9 and 5 times increase than those of market tablets (p < 0.01) respectively. These results demonstrated that SMEDDS formulations had significantly increased the oral absorption of loratadine in beagle dogs.

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 on-site and photographic evaluations of the suppressive effects of cetirizine, loratadine, and fexofenadine on skin response to histamine lontophoresis: A double-blind, crossover study in healthy volunteers

BACKGROUND

The standard method used to determine the potency of antihistaminesis to assess the degree of suppression of skin response to histamine challenge.

OBJECTIVES

The aims of this study were to compare the efficacy of 3 antihistaminesusing a histamine challenge test and the usefulness of on-site evaluation with that of photographic evaluation of skin-test reactions.

METHODS

In this prospective, double-blind, crossover study, healthy volunteerswere given cetirizine 5 mg (CTZ-5) and 10 mg (CTZ-10), loratadine 10 mg (LOR), fexofenadine 60 mg BID (FEX), and placebo (PLC), in a randomly assigned order, with an interval of at least 1 week between treatments. Before and 0.5 to 24 hours after administration, the areas of flare and wheal induced by histamine iontophoresis were measured directly (on site) by 1 evaluator and by another evaluator using photographic images on a computer monitor.

RESULTS

Ten healthy volunteers (6 men, 4 women; mean age, 28.2 years[range, 20-39 years]; mean weight, 60.7 kg [range, 41-81 kg]) were enrolled. The data from 9 subjects were analyzed; the data from 1 subject were omitted because the subject used an over-the-counter cold medication containing diphenhydramine several times during the study. By both methods, all antihistamines were shown to suppress flare significantly from 4 to 24 hours after administration. CTZ was most potent in suppressing both flare and wheal. For flare, the areas as measured using on-site evaluation were larger overall than those measured using photographic evaluation, but the shapes of the time-course graphs were similar for both. Overall, the flare area measurements started to decrease significantly from baseline values 4 hours after drug administration, reached a nadir at 10.5 hours, and remained significantly lower compared with baseline values at 24 hours. Comparisons between antihistamines showed significant differences in mean flare areas between the 2 doses of CTZ and LOR from 8 to 12 hours after administration in both evaluation methods. The wheal areas were significantly reduced from baseline values by most of the antihistamines 4 to 12 hours after drug administration, reached their lowest values at 10.5 hours, and returned to near-baseline values at 24 hours. Comparisons with PLC values at each time point, however, showed significant differences only for CTZ-5 and CTZ-10 from 4 to 12 hours after administration. Comparison between antihistamines showed significant differences in mean flare areas between the 2 doses of CTZ and LOR from 8 to 12 hours after administration in both evaluation methods. Although the flare areas measured by both methods correlated linearly (r = 0.90; P < 0.001), the correlation for wheal areas was weaker (r = 0.76; P < 0.001).

CONCLUSIONS

In this study in healthy volunteers, single doses of CTZ 5 mg and CTZ 10 mg were more potent compared with single-dose LOR 10 mg and FEX 60 mg BID in suppressing skin response. Although linear correlations were found between skin-response areas, as measured by on-site and photographic evaluation, it was difficult to differentiate between wheal and flare by photographic evaluation, especially when a typical wheal was suppressed to slightly edematous erythema by antihistamines.

Investigation of cytotoxic and genotoxic effects of the antihistaminic drug, loratadine, on human lymphocytes

CONTEXT

Loratadine (LOR) is a new generation antihistamine used in the treatment of allergic disorders.

OBJECTIVE

The aim of this study was to evaluate the cytogenotoxic effect of LOR on human peripheral blood lymphocytes.

MATERIALS AND METHODS

We investigated the genotoxic effect of this drug in cultured human peripheral blood lymphocytes using sister chromatid exchange (SCE), chromosomal aberrations (CA) and micronucleus (MN) assay in culture conditions. Proliferation index (PI), mitotic index (MI) and nuclear division index (NDI) were also calculated to determine the cytotoxic/cytostatic effect. Cultures were treated with LOR at three concentrations (5, 15 and 25 µg/ml) for 48 h.

RESULTS

Although the MI significantly decreased at the higher concentrations (15 and 25 µg/ml) compared with negative (solvent) control, LOR indicated weaker cytotoxic potential in PI and NDI values at all the tested concentrations. LOR increased the frequencies of SCE, CA and MN in all lymphocyte cultures. However, significant increase was observed in MN at the medium and highest doses (15 and 25 µg/ml) and in CA at the medium dose (15 µg/ml) compared with negative (solvent) control culture. Our results indicate that LOR has cytotoxic and genotoxic effects on human peripheral blood lymphocyte cultures.

DISCUSSION

Although most of previously findings have shown that LOR does not reflect genotoxicity, our results indicated that it may be a genotoxic drug.

CONCLUSION

More studies are necessary to elucidate the relationship between cytotoxic, genotoxic and apoptotic effects, and to make a possible risk assessment in patients receiving therapy with this drug.

Pharmacology of antihistamines

H1-antihistamines, the mainstay of treatment for urticaria, were developed from anticholinergic drugs more than 70 years ago. They act as inverse agonists rather than antagonists of histamine H1-receptors which are members of the G-protein family. The older first generation H1-antihistamines penetrate readily into the brain to cause sedation, drowsiness, fatigue and impaired concentration and memory causing detrimental effects on learning and examination performance in children and on impairment of the ability of adults to work and drive. Their use should be discouraged. The newer second-generation H1-antihistamines are safer, cause less sedation and are more efficacious. Three drugs widely used for symptomatic relief in urticaria, desloratadine, levocetirizine and fexofenadine are highlighted in this review. Of these levocetirizine and fexofenadine are the most potent in humans in vivo. However, levocetirizine may cause somnolence in susceptible individuals, whereas fexofenadine has a relatively short duration of action and may be required to be given twice daily for all round daily protection. Although desloratadine is less potent, it has the advantages of rarely causing somnolence and having a long duration of action.

Histamine produces opposing effects to serotonin in the knee joint of rats

Formalin injected in the knee joint of rats produces concentration-dependent nociception, edema, and plasma leakage (PL). Herein, we investigated the effect of histamine H1 receptor (H1R) antagonists in this model. Articular nociception was inferred from the paw elevation time (PET; seconds) during 1-minute periods of stimulated walking, determined every 5 minutes, throughout a 60-minute experimental session. Edema was evaluated by the increase in articular diameter (AD; mm), and PL was measured by the amount of Evans blue dye in the synovial fluid (PL; μg/mL). Loratadine and cetirizine, given systemically, both increased the PET. None of the treatments changed the AD and PL. Loratadine given locally with formalin increased the PET but was without effect when given in the contralateral knee. Systemic loratadine was also without effect when formalin was coinjected with sodium cromoglycate. Histamine and the selective H1R agonist 2-pyridylethylamine decreased the PET and potentiated morphine spinal analgesia, but did not affect the AD and PL. Cetirizine prevented the antinociceptive effect of the H1R agonist. The N-methyl-D-aspartate/histamine-site agonist tele-methylhistamine coinjected with formalin only increased PET. Serotonin alone had no effect on the PET and increased the AD, and the highest dose increased the PL. When coinjected with formalin, serotonin only caused hypernociception, and the highest dose also increased AD. NAN 190, cyproheptadine, and ondansetron (respectively, 5-HT1, 5-HT2, and 5-HT3 receptor antagonists) decreased the PET without changing the AD or PL. Collectively, these results suggest that in rats, the H1R plays an antinociceptive role within the knee joint, while serotonin receptors play a pronociceptive role.

PERSPECTIVE

The present study revealed an antinociceptive mechanism that has previously not been detected by traditional nociceptive tests. Our observations may help to improve the development of new pharmacological strategies for the treatment of clinically relevant pains that generally originate in deep structures.

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.

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.

Maternal use of Loratadine during pregnancy and risk of hypospadias in offspring

To examine the risk of hypospadias after exposure to loratadine and other antihistamines during pregnancy, we conducted a population-based case-control study in four Danish counties, which account for 30% of the Danish population (approximately 1.6 M). We obtained data on maternal use of antihistamines from prescription databases, and data on birth outcomes from the Danish Medical Birth Registry (MBR) and the Hospital Discharge Registry (HDR). A total of 65,383 male births with a full prescription history of the mother in the study period from 1989-2002 were available for analysis. Within this cohort, we identified cases with a diagnosis of hypospadias, and 10 selected controls per case without such a diagnosis (matched on birth month, gender and year of birth). We identified 227 cases of hypospadias recorded in the HDR within six months postpartum and 2270 controls. One case (0.4%) and eight (0.4%) controls were exposed to loratadine in the first trimester and up to 30 days before the time of conception. The adjusted odds ratio (OR) for hypospadias among users of loratadine relative to non-users was 1.4 (95% CI: 0.2-11.2) and the corresponding OR for other antihistamines was 1.9 (95% CI: 0.7-5.7). In this study, maternal exposure to loratadine did not appear to be associated with an increased risk of hypospadias when compared with other antihistamines, although it should be noted that the statistical precision of the risk estimates might be limited.

No increased risk of infant hypospadias after maternal use of loratadine in early pregnancy

The original report published in 2001 on a possible association between maternal use of loratadine and an increased risk of infant hypospadias, based on data in the Swedish Medical Birth Register 1995-2001, has been followed up by continued surveillance in the same register. The original "signal" was based on 15 infants with hypospadias among 2780 loratadine-exposed infants born, representing an adjusted odd ratio of about 2.3, statistically significant. Since then another 10 cases have been identified, and 12.5 expected. For the period 2001-2004, another 1911 loratadine-exposed infants have been identified and only two had hypospadias (4 expected). Our present position is that the primary finding was a "signal" which had occurred by chance and the follow-up agrees with independent studies which indicate an absence of an association. This illustrates the care with which apparent statistically significant increases have to be handled when no prior hypothesis exists.

Evaluation of the pharmacokinetics and electrocardiographic pharmacodynamics of loratadine with concomitant administration of ketoconazole or cimetidine

AIMS

To evaluate whether ketoconazole or cimetidine alter the pharmacokinetics of loratadine, or its major metabolite, desloratadine (DCL), or alter the effects of loratadine or DCL on electrocardiographic repolarization in healthy adult volunteers.

METHODS

Two randomized, evaluator-blind, multiple-dose, three-way crossover drug interaction studies were performed. In each study, subjects received three 10 day treatments in random sequence, separated by a 14 day washout period. The treatments were loratadine alone, cimetidine or ketoconazole alone, or loratadine plus cimetidine or ketoconazole. The primary study endpoint was the difference in mean QTc intervals from baseline to day 10. In addition, plasma concentrations of loratadine, DCL, and ketoconazole or cimetidine were obtained on day 10.

RESULTS

Concomitant administration of loratadine and ketoconazole significantly increased the loratadine plasma concentrations (307%; 90% CI 205-428%) and DCL concentrations (73%; 62-85%) compared with administration of loratadine alone. Concomitant administration of loratadine and cimetidine significantly increased the loratadine plasma concentrations (103% increase; 70-142%) but not DCL concentrations (6% increase; 1-11%) compared with administration of loratadine alone. Cimetidine or ketoconazole plasma concentrations were unaffected by coadministration with loratadine. Despite increased concentrations of loratadine and DCL, there were no statistically significant differences for the primary electrocardiographic repolarization parameter (QTc) among any of the treatment groups. No other clinically relevant changes in the safety profile of loratadine were observed as assessed by electrocardiographic parameters (mean (90% CI) QTc changes: loratadine vs loratadine + ketoconazole = 3.6 ms (-2.2, 9.4); loratadine vs loratadine + cimetidine = 3.2 ms (-1.6, 7.9)), clinical laboratory tests, vital signs, and adverse events.

CONCLUSIONS

Loratadine 10 mg daily was devoid of any effects on electrocardiographic parameters when coadministered for 10 days with therapeutic doses of ketoconazole or cimetidine in healthy volunteers. It is concluded that, although there was a significant pharmacokinetic drug interaction between ketoconazole or cimetidine and loratadine, this effect was not accompanied by a change in the QTc interval in healthy adult volunteers.

A double-blind, placebo-controlled investigation of the effects of fexofenadine, loratadine and promethazine on cognitive and psychomotor function

AIMS

To assess whether fexofenadine in a range of doses from 80 to 180 mg has any disruptive effects on aspects of psychomotor and cognitive function in comparison with placebo, loratadine and promethazine, an antihistamine known to produce psychomotor and cognitive impairment.

METHODS

Twenty-four healthy volunteers received fexofenadine 80 mg, 120 mg and 180 mg, loratadine 10 mg, promethazine 30 mg (as a positive internal control) and placebo in a six-way crossover, double-blind study. Following each dose, subjects were required to perform a series of tests of cognitive function and psychomotor performance at 1.5, 3, 6, 9, 12 and 24 h post dose. The test battery included critical flicker fusion (CFF), choice reaction time (CRT) and assessment of subjective sedation (LARS). Overall levels of activity were monitored by means of wrist mounted actigraphs throughout each of the 24 h experimental periods.

RESULTS

Fexofenadine at all doses tested was not statistically different from placebo in any of the tests used and loratadine did not cause any significant impairment of cognitive function. Significant impairments were found following promethazine. Promethazine caused a significant reduction in CFF threshold and this effect was evident up to 12 h post dose (P<0.05). There was a significant increase in recognition reaction time at 3 and 6 h post promethazine administration, and the drug caused a significant (P<0. 002) increase in the percentage of 'sleep-like' activity from actigraph records during the daytime.

CONCLUSIONS

Fexofenadine at doses up to 180 mg appears free from disruptive effects on aspects of psychomotor and cognitive function in a study where the psychometric assessments have been shown to be sensitive to impairment, as evidenced by the effects of the verum control promethazine 30 mg.