Direct chiral LC-MS/MS analysis of fexofenadine enantiomers in plasma and urine with application in a maternal-fetal pharmacokinetic study.

This study shows the development and validation of two enantioselective LC-MS/MS methods for the determination of fexofenadine in biological matrices including the elution order determination. Plasma (200 µL) or urine (50 µL) aliquots were added to the internal standard solution [(S)-(-)-metoprolol] and extracted in the acid medium with chloroform. Resolution of the (R)-(+)- and (S)-(-)-fexofenadine enantiomers was performed in a Chirobiotic V column. The methods showed linearity at the range of 0.025-100 ng/mL plasma and 0.02-10 µg/mL urine for each fexofenadine enantiomer. These methods were applied to the maternal-fetal pharmacokinetics of fexofenadine enantiomers in plasma and urine of parturient women (n = 8) treated with a single oral 60 mg dose of racemic fexofenadine. Enantiomeric ratio in plasma (AUC0-∞(R)-(+)/(S)-(-)) was close to 1.5, nevertheless in urine was closed to unity. The transplacental transfer was approximately 18% for both fexofenadine enantiomers. The enantioselective methods can also be useful in future clinical studies of chiral discrimination of drug transporters.

Pharmacokinetics and safety of repirinast tablets in healthy Chinese subjects

ABSTRACT Repirinast is a new, synthetic, disodium cromoglycate-like antiallergic agent for oral administration in humans. This study evaluated the safety, tolerability and pharmacokinetics of repirinast tablets in healthy Chinese volunteers. This was a phase I, open-label, randomized, single- and multiple-dose study. Subjects were assigned to receive a single dose of repirinast tablet at either 150, 300, or 450 mg, or multiple doses of 150 mg twice daily for 5 days. Plasma samples were analyzed with LC-MS/MS. Pharmacokinetic parameters of active metabolite MY-1250 (deesterified repirinast) were calculated using non-compartmental analysis with WinNonlin software. Statistical analysis was performed using SPSS software. All adverse events (AEs) were mild and of limited duration. No serious adverse event (SAE), death or withdrawal from the study was observed. In the single-dose study, Cmax was reached at about 0.75 hour, and the mean t1/2 was approximately 16.21 hours. Area under curve (AUC) and Cmax increased with dose escalation, but dose proportionality was not observed over the range of 150 to 450 mg. In the multiple-dose study, the steady-state was reached within 3 days with no accumulation. Repirinast tablet was well tolerated in healthy Chinese subjects.

Prevention and treatment of allergic asthma in pregnancy: from conventional drugs to new therapeutical approaches.

Different conventional anti-asthmatic and anti-allergic drugs are commonly used in pregnancy, including inhaled corticosteroids, long- and short-acting ß-agonists, leukotriene modifiers, cromolyn, and theophylline. Alternatively, immunotherapy with allergens before and during pregnancy is accepted as a causal treatment of allergies, but the allergy specifity and severity in combination with a variety of application protocols and procedures cause wide heterogenity of this treatment principle. Furthermore, the pharmacokinetic characteristics and the US Food and Drug Administration (FDA) classification of conventional anti-allergic drugs and immunological implications of immunotherapy are summarized in this review, and insights on fetal programming of allergies are introduced. We propose a potential perspective of treatment with anti-inflammatory and pro-resolving mediators, such as lipoxins, resolvins and protectins; these are lipid mediators physiologically generated during the immune response from arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid. This proposal fits with the recently appreciated approaches to allergy prevention for the newborn child by a balanced maternal nutrition and omega-3 long-chain polyunsaturated fatty acid consumption.

Safety and efficacy of fluticasone furoate in pediatric patients with perennial allergic rhinitis.

OBJECTIVE: To evaluate the safety and efficacy of once-daily (QD) fluticasone furoate (FF) nasal spray in children with perennial allergic rhinitis (PAR). STUDY DESIGN: A global, randomized, double-blind, placebo-controlled study. SUBJECTS AND METHODS: Pediatric patients (aged 2-11 years; n = 558) with PAR received once-daily placebo, FF 110 microg, or FF 55 microg for 12 weeks. Efficacy was evaluated by nasal symptom scores. General safety and corticosteroid-specific safety (nasal and ophthalmic examinations, and hypothalamic-pituitary-adrenal assessments) were assessed. RESULTS: No findings of clinical concern were identified from the safety assessments. For primary efficacy analysis of mean change from baseline over the first 4 weeks of treatment in daily reflective total nasal symptom score, FF 55 microg demonstrated significant improvement (P = 0.003) compared with placebo; however, the improvement for FF 110 microg versus placebo did not reach statistical significance (P = 0.073). CONCLUSION: FF QD was well tolerated and demonstrated efficacy in children aged 2 to 11 years with PAR.

Long-term safety of fluticasone furoate nasal spray in adults and adolescents with perennial allergic rhinitis.

BACKGROUND: Fluticasone furoate is a novel-enhanced affinity glucocorticoid and its long-term safety must be assessed. This study was designed to assess the safety and tolerability of 12-month intranasal administration of fluticasone furoate in adult and adolescent patients with perennial allergic rhinitis (PAR). METHODS: In this randomized, double-blind, placebo-controlled, parallel-group study, 806 patients with PAR were randomized to once daily (od) fluticasone furoate nasal spray 110 microg (n = 605) or vehicle placebo nasal spray (n = 201) for 12 months, following a 7- to 14-day screening period. Safety was assessed by monitoring adverse events (AEs), 24-h urinary cortisol excretion, nasal and ophthalmic examinations, electrocardiograms and clinical laboratory tests. Plasma concentrations of fluticasone furoate were determined from blood samples. RESULTS: Fluticasone furoate was well tolerated. The incidence of most AEs was similar to that observed with placebo, with the exception of epistaxis, which was more frequently reported on active treatment. There were no clinically meaningful differences between fluticasone furoate and placebo in terms of safety assessments, including mean changes in ophthalmic parameters and 24-h urine cortisol excretion. Plasma concentrations of fluticasone furoate were not quantifiable in the majority of patients following intranasal administration. CONCLUSIONS: Long-term (12-month) administration of fluticasone furoate 110 microg od revealed an AE profile typical of the intranasal corticosteroid class in both adult and adolescent patients with PAR, with no evidence of clinically relevant systemic corticosteroid exposure.

New antihistamines: a critical view

OBJETIVO: Avaliar criticamente os mais novos anti-histamínicos anti-H1 e os diferentes termos utilizados para denominá-los, com base na revisão de evidências sobre o papel dos anti-H1 no tratamento das doenças alérgicas. FONTES DOS DADOS: Artigos originais, revisões e consensos indexados nos bancos de dados MEDLINE e PUBMED de 1998 a 2006. Palavra chave: anti-histamínicos. SíNTESE DOS DADOS: Os anti-histamínicos de segunda geração diferenciam-se dos de primeira geração por sua elevada especificidade e afinidade pelos receptores H1 periféricos e pela menor penetração no sistema nervoso central (SNC), com conseqüente redução dos efeitos sedativos. Embora os anti-histamínicos de segunda geração sejam, geralmente, melhor tolerados do que seus predecessores, alguns efeitos adversos, principalmente cardiotoxicidade, surgiram com alguns deles. Nos últimos 20 anos, novos compostos, com diferentes farmacocinéticas, foram sintetizados. A maioria deles manifesta propriedades antiinflamatórias que independem de sua atividade no receptor H1. Aprimoramentos mais recentes, geralmente na forma de metabólitos ativos, levaram ao uso do termo anti-histamínico de terceira geração. Esse termo surgiu espontaneamente, sem uma descrição clara de seu significado e implicações clínicas, criando grande confusão entre os profissionais da saúde. CONCLUSÕES: Com base nas evidências sobre anti-histamínicos anti-H1, nenhum deles pode ser considerado como "anti-histamínico de terceira geração". Para tanto, seria preciso comprovar que a nova classe de anti-histamínicos possui vantagens clínicas distintas sobre os compostos existentes e preenche pelo menos três pré-requisitos: ausência de cardiotoxicidade, de interações medicamentosas e de efeitos sobre o SNC.

OBJECTIVE: To perform a critical evaluation of the more recent H1 antihistamines and the various terms used to describe them, based on a review of evidence on their role in the treatment of allergic disorders. SOURCES: Original articles, reviews and consensus documents published from 1998 to 2006 and indexed in the MEDLINE and PubMed databases. Keyword: antihistamines. SUMMARY OF THE FINDINGS: 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 of the central nervous system (CNS), having fewer sedative effects as a result. Whilst second-generation antihistamines are in general better tolerated than their predecessors, some adverse effects, principally cardiotoxicity, have been observed with some of them. Over the last 20 years, new compounds with different pharmacokinetic properties have been synthesized. The majority of these exhibit anti-inflammatory properties that are independent of their action on the H1 receptor. More recent improvements, generally in the form of active metabolites, led to the use of the term third-generation antihistamines. This term emerged spontaneously, with no clear definition of its meaning or clinical implications, creating great confusion among healthcare professionals. CONCLUSIONS: On the basis of the evidence on H1 antihistamines, none of them deserve the title"third-generation antihistamine." As the Consensus Group on New Generation Antihistamines concluded, to merit this definition, a new class of antihistamines would have to demonstrate distinct clinical advantages over existing compounds and fulfill at least three prerequisites: they should be free from cardiotoxicity, drug interactions and effects on the CNS.