Epidemiology of adult chronic cough: disease burden, regional issues, and recent findings

Benzonatate Safety and Effectiveness: A Systematic Review of the Literature

OBJECTIVE

To review the available literature regarding the treatment effects and efficacy of benzonatate needed to better inform patients, providers, and regulators evaluating its role in modern medical therapies.

DATA SOURCES

Comprehensive literature searches were conducted in PubMed, Embase (Elsevier), Cochrane Library, and Scopus for original research articles evaluating the effectiveness, tolerability, and safety profile of benzonatate from January 1956 through August 2022.

STUDY SELECTION AND DATA EXTRACTION

The identified studies were screened for relevance and then assessed for inclusion through a full-text review, data extraction, and quality assessment by multiple reviewers using the online software Covidence.

DATA SYNTHESIS

The selection process resulted in 37 articles consisting of 21 cohort studies, 5 experimental studies, and 11 case studies and series. Initial clinical studies exploring potential therapeutic benefits collected data from very small populations and limited clinical settings. Safety is primarily assessed in terms of toxicity due to overdose or inappropriate use. Quality assessment raised concerns for high degrees of biases primarily related to the limited sample size, data collection, generalizability, and study design.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review reveals substantial limitations within existing evidence pertaining to the safety and clinical effectiveness of benzonatate and thus, a need for large observational studies or randomized trials to better characterize its role and value in modern medical practice.

CONCLUSIONS

Rising safety concerns should bring closer scrutiny upon the prescription of benzonatate whose approval is founded upon evidence that would not stand up to current regulatory review.

Multiple Chemical Sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersensitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psychosocial influences. The development of MCS may be attributed to the sensitization of transient receptor potential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

Extracellular vesicles and COPD: foe or friend?

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease characterized by progressive airflow limitation. The complex biological processes of COPD include protein hydrolysis tissue remodeling, innate immune inflammation, disturbed host-pathogen response, abnormal cellular phenotype conversion, and cellular senescence. Extracellular vesicles (EVs) (including apoptotic vesicles, microvesicles and exosomes), are released by almost all cell types and can be found in a variety of body fluids including blood, sputum and urine. EVs are key mediators in cell-cell communication and can be used by using their bioactive substances (DNA, RNA, miRNA, proteins and other metabolites) to enable cells in adjacent and distant tissues to perform a wide variety of functions, which in turn affect the physiological and pathological functions of the body. Thus, EVs is expected to play an important role in the pathogenesis of COPD, which in turn affects its acute exacerbations and may serve as a diagnostic marker for it. Furthermore, recent therapeutic approaches and advances have introduced EVs into the treatment of COPD, such as the modification of EVs into novel drug delivery vehicles. Here, we discuss the role of EVs from cells of different origins in the pathogenesis of COPD and explore their possible use as biomarkers in diagnosis, and finally describe their role in therapy and future prospects for their application. Graphical Abstract.

Effectiveness and Safety of Codeine and Levodropropizine in Patients With Chronic Cough

BACKGROUND

Recent progress in chronic cough management includes controlling cough triggers and hypersensitivity using antitussives. Therefore, we investigated the effects and safety outcomes of antitussives, codeine and levodropropizine, in patients with chronic cough.

METHODS

We conducted an open-label, randomized comparative trial with newly referred patients with chronic cough. Patients were orally administered codeine (60 mg/day) and levodropropizine (180 mg/day) for 2 weeks. Cough severity, including the visual analog scale (VAS), Cough Symptom Score (CSS), Leicester Cough Questionnaire (LCQ), and safety for each treatment were assessed. The primary outcome was VAS score changes before and after 2 weeks of treatment.

RESULTS

Among the 88 participants, 45 and 43 in the codeine and levodropropizine groups, respectively, were included in the analysis. Changes in the VAS score were higher in the codeine group than in the levodropropizine group (35.11 ± 20.74 vs. 19.77 ± 24.83, P = 0.002). Patients administered codeine also had improved CSS (2.96 ± 2.35 vs. 1.26 ± 1.89, P < 0.001) and LCQ (3.28 ± 3.36 vs. 1.61 ± 3.53, P = 0.025) than those administered levodropropizine. Treatment-related adverse events, including drowsiness, constipation, and headaches, were more frequent in the codeine group than in the levodropropizine group. However, no significant differences existed in the adverse events leading to discontinuation.

CONCLUSION

Codeine is an effective and generally well-tolerated antitussive for chronic cough. However, it may induce side effects in some patients. Individual responses and adverse events should be carefully monitored when codeine is used to treat chronic cough.