Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference

Clinical efficacy of inhaled corticosteroids in equine asthma: A meta-analysis and number needed to treat

Equine asthma, a prevalent chronic inflammatory condition affecting the equine population, significantly compromises the performance and quality of life in affected horses. Inhaled corticosteroids (ICS) are often the first-line pharmacological intervention due to their potent anti-inflammatory properties. This meta-analysis investigates the clinical efficacy of ICS in treating equine asthma, emphasizing the number needed to treat (NNT) and the likelihood of achieving a clinical response. A comprehensive literature search identified relevant studies comparing ICS with placebo (PCB) controlled treatments. Data were synthesized from four clinical trials involving 252 asthmatic horses. Results indicate an overall NNT of 3.2 (95 % CI 2.3-4.7), meaning that approximately three horses must be treated with ICS for one to achieve a significant clinical response. Additionally, the relative risk of achieving clinical improvement with ICS versus PCB was 1.73 (95 % CI 1.47-2.02), demonstrating a marked increase in therapeutic effectiveness. Subgroup analysis revealed an NNT of 3.0 for severe cases, underscoring the efficacy of ICS across different severity levels. Despite potential biases noted in some studies, sensitivity analyses confirmed the robustness of these findings. The GRADE assessment rated the quality of evidence as high. These results highlight the therapeutic value of ICS in managing equine asthma, providing evidence-based recommendations for their clinical use. Future research should explore long-term outcomes and potential synergistic effects of ICS combined with other treatments to enhance clinical efficacy in managing equine asthma.

Chronic Cough and Hyperpnea: Clinical Approach to Equine Asthma

Exercise intolerance, chronic cough, and hyperpnea are the clinical hallmarks of equine asthma. Diagnosis of severe equine asthma in horses is multistep; determination of the phenotype will help guide future recommendations. Management of equine asthma is largely reduction/elimination of triggering agents/conditions. Immunosuppressive therapies and bronchodilators are the mainstay of treatment of equine asthma. Rescue therapy with short-acting bronchodilators is the first goal when managing a horse with hyperpnea. The second goal is to control/reduce inflammation and airway remodeling. Immunosuppressive therapies alone will not be effective. Environmental and management changes must be established to minimize or eliminate exposure to triggering agents/factors.

Inhaled ciclesonide is efficacious and well tolerated in the treatment of severe equine asthma in a large prospective European clinical trial

Background

Ciclesonide is a glucocorticoid prodrug, already registered for human use. Due to its mode of action and inhaled route of administration, it was considered an appropriate treatment option for horses with severe equine asthma. Although the efficacy of inhaled ciclesonide has been demonstrated in horses with asthma exacerbations under controlled mouldy hay challenge conditions, it has not yet been reported under field conditions.

Objectives

To assess the effectiveness and safety of inhaled ciclesonide for the treatment of severe equine asthma.

Study design

Prospective, multicentre, placebo‐controlled, randomised, double‐blinded study.

Methods

Two‐hundred and twenty‐four client‐owned horses with severe equine asthma were randomised (1:1 ratio) to receive either ciclesonide inhalation (343 µg/actuation) solution or placebo (0 µg/actuation). Treatments (placebo or ciclesonide) were administered with a nonpressurised Soft Mist™ inhaler specifically developed for horses (Aservo^® EquiHaler^®) at doses of 8 actuations twice daily for the first 5 days and 12 actuations once daily for the following 5 days. Primary outcome was a success/failure analysis with the a priori definition of treatment success as a 30% or greater reduction in weighted clinical score (WCS) between Day 0 and Day 10 (±1).

Results

The treatment success rate (as defined above) in ciclesonide‐treated horses was 73.4% (80/109) after 10 (±1) days of treatment, being significantly higher than in the placebo group with 43.2% (48/111; P < 0.0001). Few systemic and local adverse events of ciclesonide were observed.

Main limitations

The severity of clinical signs of severe equine asthma varies over time; despite the prohibition of environmental management changes during the study, a placebo effect was also identified. This potentially contributed, in part, to the clinical improvement observed in the ciclesonide‐treated group.

Conclusions

Ciclesonide inhalation solution administered by the Aservo^® EquiHaler^® effectively reduced severity of clinical signs in a majority of horses with severe equine asthma and was well tolerated.

Adding a Second Bronchodilator in COPD: A Meta-Analysis on the Risk of Specific Cardiovascular Serious Adverse Events of Tiotropium/Olodaterol Fixed-Dose Combination

Dual bronchodilation therapy represents the cornerstone for the treatment of COPD. A large retrospective study reports that adding a second long-acting bronchodilator in patients with COPD significantly increases the risk of heart failure. Nevertheless, retrospective studies are characterized by limitations including misdiagnosis and inaccuracy of recordkeeping. This study aimed to ascertain whether tiotropium/olodaterol (T/O) 5/5 μg fixed-dose combination (FDC) may modulate the risk of main cardiovascular outcomes in COPD patients enrolled in randomized controlled trials (RCTs). A meta-analysis (CRD42017070100) was performed by selecting RCTs reporting raw data from the ClinicalTrials.gov database concerning the impact of T/O 5/5 µg FDC vs. monocomponents on the occurrence of specific cardiovascular serious adverse events: arrhythmia, heart failure, myocardial infarction, and stroke. Data were reported as relative risk and 95% Confidence Interval, and the risk of publication bias assessed via Egger's test. Eighty six full text articles were identified, and 10 RCTs published in 7 studies between 2015 and 2018 were included into the analysis. Data obtained from 12,690 COPD patients (44.47% T/O FDC, 55.53% monocomponents) were extracted. T/O 5/5 μg FDCs did not significantly modulate (p-value > 0.05) the risk of arrhythmia (1.02, 0.55 - 1.92), heart failure (0.88, 0.41 - 1.92), myocardial infarction (1.15, 0.70 - 1.87), and stroke (0.98, 0.44 - 2.16) vs. monocomponents. No significant publication bias affected the effect estimates of this meta-analysis. The results of this quantitative synthesis indicate that dual bronchodilation with T/O 5/5 μg FDC is characterized by an acceptable cardiovascular safety profile in COPD patients.

Isolated airways in equine respiratory pharmacology: They never lie

Pre-clinical studies on human isolated bronchi have relevant translational value in human in vivo, conversely no investigation has been performed to assess whether data resulting from equine isolated airways can have any translational application in asthmatic horses. Thus, a meta-regression analysis via random-effect method was carried out to correlate the pharmacological characteristics of bronchodilators resulting from experiments performed in equine isolated bronchi with their impact on the lung function outcomes in asthmatic horses. Data on the potency of different bronchodilators were extracted from four ex vivo studies involving 68 horses, and related with the maximum change in transpulmonary pressure (ΔPpl_max), pulmonary resistance (R_L), and dynamic lung compliance (C_dyn) resulting from the meta-analysis of clinical trials aimed to assess the effect of different bronchodilator classes, namely antimuscarinic agents and β₂-adrenoreceptor (β₂-AR) agonists, on lung function of asthmatic horses. The potency (pEC₅₀) detected in equine isolated bronchi for each specific bronchodilator did not significantly (P > 0.05) influence the bronchorelaxant effect resulting from clinical trials. R_L was characterized by a flatter meta-regression line (slope 0.01, 95%CI -0.25 - 0.28) with respect to ΔPpl_max (slope 0.90, 95%CI -4.06 - 2.26) and C_dyn (slope 0.09, 95%CI -0.21 - 0.04). The quality of evidence was moderate for R_L and ΔPpl_max and low for C_dyn. This quantitative synthesis provides the indirect evidence that pre-clinical investigations performed by using equine isolated airways may produce useful data to predict the impact of bronchodilators on the R_L of asthmatic horses. Further translational studies are needed to directly confirm the results of this research.