Study protocol: a phase III randomised, double-blind, parallel arm, stratified, block randomised, placebo-controlled trial investigating the clinical effect and cost-effectiveness of sertraline for the palliative relief of breathlessness in people with chronic breathlessness

Mirtazapine for chronic breathlessness? A review of mechanistic insights and therapeutic potential

INTRODUCTION

Chronic breathlessness is a common and distressing symptom of advanced disease with few effective treatments. Central nervous system mechanisms are important in respiratory sensation and control. Consequently, drugs which may modify processing and perception of afferent information in the brain may have a role. Antidepressants have been proposed; however, current evidence is limited. Of potentially suitable antidepressants, mirtazapine is an attractive option given its tolerability profile, low cost, and wide availability, along with additional potential benefits. Areas covered: The paper provides an overview of the physiology of breathlessness, with an emphasis on central mechanisms, particularly the role of fear circuits and the associated neurotransmitters. It provides a potential rationale for how mirtazapine may improve chronic breathlessness and quality of life in patients with advanced disease. The evidence was identified by a literature search performed in PubMed through to October 2018. Expert opinion: Currently, there is insufficient evidence to support the routine use of antidepressants for chronic breathlessness in advanced disease. Mirtazapine is a promising candidate to pursue, with definitive randomized controlled trials required to determine its efficacy and safety in this setting.

Sertraline in symptomatic chronic breathlessness: a double blind, randomised trial

Does sertraline provide symptomatic relief for chronic breathlessness in people with advanced disease whose underlying cause(s) are optimally treated?

223 participants with chronic breathlessness (modified Medical Research Council breathlessness scale ≥2) who had optimal treatment of underlying cause(s) were randomised 1:1 to sertraline 25–100 mg (titrated upwards over 9 days) or placebo for 4 weeks. The primary outcome was the proportion who had an improvement in intensity of current breathlessness >15% from baseline on a 100-mm visual analogue scale.

The proportion of people responding to sertraline was similar to placebo for current breathlessness on days 26–28 (OR 1.00, 95% CI 0.71–1.40) and for other measures of breathlessness. Quality of life in the sertraline arm had a higher likelihood of improving than in the placebo arm over the 4 weeks (OR 0.21, 95% CI 0.01–0.41; p=0.044). No differences in performance status, anxiety and depression, or survival were observed. Adverse event rates were similar between arms.

Sertraline does not appear to provide any benefit over placebo in the symptomatic relief of chronic breathlessness in this patient population.

Use of mirtazapine in patients with chronic breathlessness: A case series

BACKGROUND

Breathlessness remains a common and distressing symptom in people with advanced disease with few effective treatment options. Repurposing of existing medicines has been effective in other areas of palliative care, for example, antidepressants to treat pain, and offers an opportunity to deliver improved symptom control in a timely manner. Previous case series have shown reduced breathlessness following the use of sertraline (a selective serotonin reuptake inhibitor) in people with chronic obstructive pulmonary disease.

CASES

Six cases where mirtazapine, a noradrenergic and specific serotonergic antidepressant, was used to treat chronic breathlessness in advanced lung disease. Case management: All cases received mirtazapine at a starting dose of 15 mg, prescribed under the care of their primary care physician. Cases had been receiving mirtazapine for a variable time period (2 weeks to 5 months) at the time of the interviews. Case outcome: All cases reported less breathlessness and being able to do more. They described feeling more in control of their breathing, and being able to recover more quickly from episodes of breathlessness. Some cases also reported beneficial effects on anxiety, panic, appetite and sleep. No adverse effects were reported.

DISCUSSION

Patients with chronic breathlessness in this case series reported benefits during mirtazapine treatment. To determine the effectiveness of mirtazapine in alleviating breathlessness and improving quality of life in chronic lung disease, blinded randomised trials are warranted.

Non-opioid medications for the relief of chronic breathlessness: current evidence

INTRODUCTION

To evaluate systematically randomised clinical trials investigating non-opioid medications for the management and treatment of chronic breathlessness. Areas covered: The evidence for the role of benzodiazepines, anxiolytics, selective serotonin re-uptake inhibitors (SSRIs), tricyclic antidepressants, antihistamines, cannabinoids, nebulized furosemide and herbal-based treatments were critically reviewed. Search of the Clinical Trials Registry (Clinicaltrial.gov) identified ongoing studies expected to generate new data in the near future in several classes of non-opioid medications for their net effect on chronic breathlessness. Expert commentary: Morphine still has the best level of evidence for the symptomatic treatment of chronic breathlessness. Non-opioid treatments for chronic breathlessness are less studied than morphine and morphine-related medications although evidence is emerging in relation to some options. Currently, there is insufficient evidence to recommend non-opioids in the routine treatment of chronic breathlessness. There is a need to find agents, new as well as re-purposed, that can be used as alternative therapies to opioids for chronic breathlessness for people who are unable to tolerate morphine.