Therapeutic effects of nebulized verapamil on chronic obstructive pulmonary disease: A randomized and double‐blind clinical trial

Cardiovascular diseases or type 2 diabetes mellitus and chronic airway diseases: mutual pharmacological interferences

Chronic airway diseases (CAD), mainly asthma and chronic obstructive pulmonary disease (COPD), are frequently associated with different comorbidities. Among them, cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) pose problems for the simultaneous treatment of CAD and comorbidity. Indeed, there is evidence that some drugs used to treat CAD negatively affect comorbidity, and, conversely, some drugs used to treat comorbidity may aggravate CAD. However, there is also growing evidence of some beneficial effects of CAD drugs on comorbidities and, conversely, of the ability of some of those used to treat comorbidity to reduce the severity of lung disease. In this narrative review, we first describe the potential cardiovascular risks and benefits for patients using drugs to treat CAD and the potential lung risks and benefits for patients using drugs to treat CVD. Then, we illustrate the possible negative and positive effects on T2DM of drugs used to treat CAD and the potential negative and positive impact on CAD of drugs used to treat T2DM. The frequency with which CAD and CVD or T2DM are associated requires not only considering the effect that drugs used for one disease condition may have on the other but also providing an opportunity to develop therapies that simultaneously favorably impact both diseases.

Unraveling antibiotic resistance mechanisms in Mycobacterium abscessus: the potential role of efflux pumps

OBJECTIVES

Mycobacterium abscessus is an opportunistic respiratory pathogen in patients with underlying lung disease. It is infamously known for its low treatment success rates because of its resistance to multiple classes of antibiotics. Further insight into M. abscessus resistance mechanisms is needed to improve treatment options. In this in vitro study, the role of efflux pumps in reaction to antibiotic stress is explored, as well as the ability of the putative efflux inhibitors, thioridazine and verapamil, to potentiate the activity of guideline-recommended antibiotics.

METHODS

To evaluate the effects of antibiotic stress on mycobacterial efflux pumps, M. abscessus subspecies abscessus was exposed to amikacin, cefoxitin, clarithromycin, clofazimine, and tigecycline for 24 hours. Transcriptomic responses were measured by RNA sequencing to gain insight into upregulation of efflux pump encoding genes. Subsequently, in time-kill kinetics assays, the above-mentioned antibiotics were combined with thioridazine and verapamil to evaluate their potentiating capacity.

RESULTS

All five antibiotics led to a fold change of ≥2 Log₂ in expression of one or more genes encoding transporter systems. This effect was most pronounced for the ribosome-targeting antibiotics amikacin, clarithromycin, and tigecycline. Time-kill kinetics assays demonstrated synergy between amikacin, tigecycline, clofazimine, cefoxitin, and both thioridazine and verapamil.

CONCLUSION

Antibiotic stressors induce expression of efflux pump encoding genes in M. abscessus, especially antibiotics that target the ribosome. Putative efflux inhibitors thioridazine and verapamil show synergy with various guideline-recommended antibiotics, making them interesting candidates for the improvement of M. abscessus treatment.

Physiologic function of mediastinum space

The mediastinum forms the central part of the thoracic cavity that is surrounded by pleural space on the two sides, thoracic vertebrae at the posterior, thoracic inlet on the top, and diaphragm at the bottom. It encompasses cardiopulmonary organs and organ systems. Pathological dysfunction or deformity in any part of the mediastinum can have adverse cardiovascular and respqiratory effects. Pectus excavatum and pectus carinatum are the most common congenital chest deformities that are characterized by sternal depression and protuberance of the sternum, respectively. Together, these account for 90% of chest wall deformities. Patients are known to be represented with respiratory distress and cardiovascular dysfunction. The aim of the review article is to present the anatomical and physiological role of the mediastinum in association with important parts of the thoracic cavity and pathological dysfunction of the mediastinum (cardiopulmonary system) due to pectus excavatum and pectus carinatum.

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Mediastinum forms the central part of thoracic cavity that is surrounded by pleural space.

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PC and PE are structural chest deformities.

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Chest deformation by pressing on the chin causes coughing, stridor, dyspnea and exacerbation.

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Clinical symptoms along with inflammation that requires urgent medical treatment.

Lung deposition and systemic bioavailability of dose delivered to smoker compared with non-smoker COPD subjects

INTRODUCTION

Inhaled drugs are the most commonly used class of medications for COPD subjects. No studies have been performed to assess the influence of smoking on lung deposition of aerosolized medication, especially for the exacerbated COPD subject. The present study aimed to assess the influence of smoking on the lung deposition of the aerosol delivered to exacerbated COPD subjects.

METHODS

Twenty-four exacerbated COPD subjects using automatic continuous positive airway pressure (Auto-CPAP), 12 smokers (six females) and 12 non-smokers (six females) were recruited in the study. The subjects participated in the study received four salbutamol study doses; 1200 µg (12 puffs 100 µg/puff) of salbutamol emitted from pMDI canister connected to AeroChamber MV spacer; 1200 µg of salbutamol emitted from pMDI canister connected to Combihaler spacer; 1 mL of salbutamol respirable solution (5000 µg/mL) nebulized by Aerogen Solo connected to its T-piece; and 1 mL of salbutamol respirable solution nebulized by Aerogen Solo connected to Combihaler spacer with 2 puffs salbutamol MDI (200 µg salbutamol) before nebulisation. The subjects were randomised to receive the four selected dose-adaptor combination in a sealed envelope design on days 1, 3, 5 and 7. A washout period of 24 hours was provided between each salbutamol dosing. Auto-CPAP was adjusted at non-invasive ventilation mode with the integrated heated humidifier, as a source of humidity. Urine samples were provided by subjects, 30 minutes and cumulatively 24 hours post inhalation, as an index of the relative and systemic bioavailability, respectively, and aliquots were retained for salbutamol analysis using solid-phase extraction and high-performance liquid chromatography (HPLC). On day 2 of the study, a collecting filter was placed between the aerosol generator and the subject's mask so that the subjects would not inhale the salbutamol delivered. The same study doses and/or adapters were delivered to each subject, with filters changed with each dose-adapter combination. Salbutamol entrained on the filter was desorbed to be analysed by the HPLC.

RESULTS

Significantly higher lung deposition (30 minutes urinary salbutamol) was detected with the non-smoker compared with smokers (P < .05). Significantly higher systemic bioavailability (pooled 24-hour urinary salbutamol) for smokers compared with non-smokers was found with Aerogen Solo connected to its T-piece and CombiHaler spacer with pMDI (P < .05) only. Significantly higher amount desorbed from the ex-vivo filter were found from pMDI with both spacers in non-smokers (P < .05) compared with the smokers.

CONCLUSION

The study demonstrated that smoking reduced the lung deposition of inhaled salbutamol delivered by nebulizer or pMDI. However, the smoking effect on cytochrome p450 was observed to increase systemic absorption of the ingested portion of the inhaled dose. The lower lung deposition and possible higher systemic absorption should be taken into consideration while prescribing inhaled medication to COPD smokers especially exacerbated patients that need ventilation. Further studies are needed.