A phase I clinical trial assessing the safety, tolerability, and pharmacokinetics of inhaled ethanol in humans as a potential treatment for respiratory tract infections

Background

Current treatments for respiratory infections are severely limited. Ethanol's unique properties including antimicrobial, immunomodulatory, and surfactant-like activity make it a promising candidate treatment for respiratory infections if it can be delivered safely to the airway by inhalation. Here, we explore the safety, tolerability, and pharmacokinetics of inhaled ethanol in a phase I clinical trial.

Methods

The study was conducted as a single-centre, open-label clinical trial in 18 healthy adult volunteers, six with no significant medical comorbidities, four with stable asthma, four with stable cystic fibrosis, and four active smokers. A dose-escalating design was used, with participants receiving three dosing cycles of 40, 60%, and then 80% ethanol v/v in water, 2 h apart, in a single visit. Ethanol was nebulised using a standard jet nebuliser, delivered through a novel closed-circuit reservoir system, and inhaled nasally for 10 min, then orally for 30 min. Safety assessments included adverse events and vital sign monitoring, blood alcohol concentrations, clinical examination, spirometry, electrocardiogram, and blood tests.

Results

No serious adverse events were recorded. The maximum blood alcohol concentration observed was 0.011% immediately following 80% ethanol dosing. Breath alcohol concentrations were high (median 0.26%) following dosing suggesting high tissue levels were achieved. Small transient increases in heart rate, blood pressure, and blood neutrophil levels were observed, with these normalising after dosing, with no other significant safety concerns. Of 18 participants, 15 completed all dosing cycles with three not completing all cycles due to tolerability. The closed-circuit reservoir system significantly reduced fugitive aerosol loss during dosing.

Conclusion

These data support the safety of inhaled ethanol at concentrations up to 80%, supporting its further investigation as a treatment for respiratory infections.Clinical trial registration: identifier ACTRN12621000067875.

Acquisition and eradication of P. aeruginosa in young children with cystic fibrosis

When do infants and young children with cystic fibrosis acquire infection with Pseudomonas aeruginosa? Can this be eradicated when first detected? Children <6 yrs of age participated in an annual bronchoalveolar lavage (BAL)-based microbiological surveillance programme in Perth, Australia. When P. aeruginosa was detected, an eradication programme using combination treatment with i.v., oral and nebulised antibiotics was undertaken. Repeat BAL was performed 3 months following treatment, to assess eradication success. P. aeruginosa was detected in 33 (28.4%) children; median (range) age at detection was 30.5 (3.3-71.4) months. P. aeruginosa was mucoid at detection in six (18.2%) out of 33 patients and associated with respiratory symptoms in 16 (48.5%) out of 33 children. In total, 26 children underwent eradication therapy, with P. aeruginosa eradicated in 20 (77%) out of 26 following one eradication cycle and in three (total 88%) additional children following a second cycle. Eradication was associated with a significant decrease in neutrophil elastase and interleukin-1beta in BAL fluid 12 months post eradication. Eradication of Pseudomonas aeruginosa infection is achievable in young children with cystic fibrosis for up to 5 yrs using combination i.v., oral and nebulised antibiotic therapy and is associated with reduced pulmonary inflammation 12 months post eradication.

Congenital bronchopulmonary vascular malformations: clinical application of a simple anatomical approach in 25 cases

Congenital malformations of the bronchopulmonary airway and related arterial blood supply are a complex group of lesions in which abnormalities of venous drainage and lung parenchyma may coexist. Twenty five cases have been analysed, by a method whereby each anatomical component is separately considered. All 25 patients had abnormalities of the tracheobronchial tree, with no connection to the abnormal segment in nine cases. The aberrant arterial blood supply was single in 16 cases and multiple in nine cases, one patient from the latter group having a mixed pulmonary and systemic arterial supply to a part of the abnormal segment. Seventeen patients had anomalous venous drainage. In nine of these the vein or veins (they were multiple in four cases) drained the major part or the whole of the lung, whereas the aberrant arterial supply was limited to the right lower zone--that is, mismatched anomalous venous drainage. Abnormalities of lung parenchyma included changes within the lesion (for example, cysts, foregut inclusions) and associated abnormalities of surrounding lung (for example, hypoplasia, abnormal lobation). This information, together with the clinical features and haemodynamic data, was found to be essential for decisions on appropriate management. Patients presenting in infancy with haemodynamic disturbance continue to present major management problems (50% mortality), particularly if there are associated congenital heart defects. The role of aberrant systemic artery occlusion or ligation as a first stage procedure is well established in patients with haemodynamic abnormalities. There may be a place for this procedure in selected patients who have no haemodynamic disturbance at presentation.

Pulmonary sequestration and related congenital bronchopulmonary-vascular malformations: nomenclature and classification based on anatomical and embryological considerations

The pulmonary sequestration spectrum and related congenital lung anomalies present an extremely complex and varied group of bronchopulmonary-vascular malformations. Previous attempts at nomenclature and classification have proved inadequate. In this article we present a classification of the newly named pulmonary malinosculation spectrum, which includes all congenital lung anomalies where there is abnormal connection (that is, malinosculation) of one or more of the four major components of lung tissue--namely, tracheobronchial airway, lung parenchyma, arterial supply, and venous drainage, which in various combinations make up these lesions. We feel that this simple descriptive approach will improve our understanding and management of these complicated lesions and this is supported by the clinical experience we report in the next article.

The crossover lung segment: congenital malformation associated with a variant of scimitar syndrome

Three cases of a congenitally misplaced segment of lung are described. In one case the abnormal segment was identified at thoracotomy; it extended from an origin in the right upper lobe across the midline into the left hemithorax. The remaining two patients, with identical radiographic features, were identified in a review of 24 cases of bronchovascular malformation. In all three patients the crossover segment was associated with a variant of the scimitar syndrome: right lung hypoplasia with dextrocardia, aberrant systemic arterial supply to the right lower lobe, and anomalous venous drainage of the whole of the right lung, and in two patients with eventration of the right diaphragm.