Adverse respiratory effects of opioids for chronic breathlessness: learning lessons from chronic pain

Neuronal mechanisms underlying opioid-induced respiratory depression: our current understanding

Opioid-induced respiratory depression (OIRD) represents the primary cause of death associated with therapeutic and recreational opioid use. Within the United States, the rate of death from opioid abuse since the early 1990s has grown disproportionally, prompting the classification as a nationwide "epidemic." Since this time, we have begun to unravel many fundamental cellular and systems-level mechanisms associated with opioid-related death. However, factors such as individual vulnerability, neuromodulatory compensation, and redundancy of opioid effects across central and peripheral nervous systems have created a barrier to a concise, integrative view of OIRD. Within this review, we bring together multiple perspectives in the field of OIRD to create an overarching viewpoint of what we know, and where we view this essential topic of research going forward into the future.

Transmucosal Buprenorphine in the Treatment of Dyspnea: Case Series and Review of the Literature

Full μ-opioid agonists are commonly employed in advanced disease to relieve dyspnea of various etiologies. Although there are ongoing debates and studies regarding the relative efficacy of different agents, a factor limiting more general use is a concern about side effects, in particular respiratory depression. Buprenorphine is a partial μ receptor agonist and a κ-opioid receptor antagonist, with a better safety profile than full μ receptor agonists. We conducted a literature search, which did not reveal any studies looking at the use of buprenorphine to treat dyspnea. We also report a case series of three patients with dyspnea of various etiologies treated with buprenorphine, with an apparent excellent response of dyspnea to treatment, without any significant side effects. Given those results, as well as the potential impact of κ-opioid receptor antagonism on dyspnea-associated anxiety, we conclude that there is a need for controlled studies of buprenorphine against full μ-opioid agonists for the symptomatic treatment of dyspnea in palliative care.

Supportive and palliative care for people with respiratory problems and preexisting serious mental illness

PURPOSE OF REVIEW

People living with serious mental illness are at a higher risk of developing respiratory problems that can lead to increased morbidity and early mortality. This review aimed to identify recent advances in care provision for people with respiratory problems and preexisting serious mental illness to ease symptom burden and reduce the risk of premature mortality.

RECENT FINDINGS

Intervention-based studies in this area are scarce. The evidence reviewed originated from observational studies. Concluding comments from the synthesis suggest there are specific needs for proactive screening of respiratory function as part of routine physical health checks across care settings for people living with serious mental illness, more stringent monitoring of comorbid chronic lung conditions and increased attention in reducing the frequency respiratory infections. Integrated services across care settings are needed to support people with serious mental illness to limit the impact of modifiable lifestyle factors known to be detrimental to respiratory health, such as smoking.

SUMMARY

Key priorities are identified to improve accessibility and inclusivity of respiratory care pathways for people living with serious mental illness to support early detection and proactive monitoring of respiratory problems to help reduce the risk of early mortality.

Updates in opioid and nonopioid treatment for chronic breathlessness

PURPOSE OF REVIEW

Chronic breathlessness is a troublesome symptom experienced by people with advanced malignant and nonmalignant disease. Disease-directed therapies are often insufficient in the management of chronic breathlessness. Therefore, pharmacological and nonpharmacological breathlessness-specific interventions should be considered for select patients.

RECENT FINDINGS

There is some evidence to support the use of low-dose opioids (≤30 mg morphine equivalents per day) for the relief of breathlessness in the short term. However, additional studies are needed to understand the efficacy of opioids for chronic breathlessness in the long term.Nonopioid therapies, including inspiratory muscle training, fan-to-face therapy, L-menthol and inhaled nebulized furosemide show some promise for the relief of breathlessness in advanced disease. There is insufficient evidence to support the use of anxiolytics and benzodiazepines and cannabis for chronic breathlessness.

SUMMARY

More research is needed to identify therapies for the management of chronic breathlessness.