The role of the larynx in chronic cough

Determining What Represents Value in the Treatment of Refractory or Unexplained Chronic Cough from the Perspective of Key Stakeholders in Spain Using Multi-Criteria Decision Analysis

BACKGROUND AND OBJECTIVE

Chronic cough is defined as cough lasting for more than 8 weeks. It can be described as refractory when persisting despite thorough clinical assessment and treatment of any cough-related underlying condition, or unexplained when no underlying cough-related condition can be identified. Refractory or unexplained chronic cough (RCC|UCC) greatly affects patient health-related quality of life (HRQoL). Although around 10% of the population suffer from chronic cough (with 40-60% of these patients suffering from RCC|UCC), there is limited information available in the literature about the condition and the assessment of treatment success. This study aimed to determine what represents value in the treatment of RCC|UCC from the perspective of key stakeholders in Spain using Multi-Criteria Decision Analysis (MCDA) methodology.

METHODS

A literature review was conducted to adapt the MCDA framework to the specific context of RCC|UCC. A total of 24 participants were involved, representing three key stakeholder groups (7 patients, 9 physicians and 8 hospital pharmacists). The study was structured in two phases. In Phase 1, participants validated the adapted MCDA framework and assigned relative weights (100-point allocation) to the framework's value criteria/sub-criteria during three individual stakeholder meetings, one per each stakeholder group. In Phase 2, participants were brought together in a multi-stakeholder meeting to review findings of each stakeholder group, after which stakeholders repeated the weighting exercise as a collective group. All meetings included reflective discussion by participants of each value criteria/sub-criteria included within the adapted MCDA framework, where stakeholders shared their perspectives and opinions on what represents value in RCC|UCC.

RESULTS

Refractory or unexplained chronic cough is regarded as a chronic medical condition, with variable severity across patients and the potential to heavily impact their HRQoL (including physical, psychological and social/work productivity domains). Current treatments used by healthcare professionals, which have not been specifically developed and are not approved for RCC|UCC, show limited clinical effectiveness and associated safety and tolerability issues, which result in frequent treatment discontinuations. The reduction of the average cough frequency over a 24-h period is regarded as the primary goal of treatment by stakeholders, with the aim of improving HRQoL. Improvement of other cough symptoms, such as intensity, is also considered important. Minor adverse events and a slower onset of treatment effect would be acceptable to stakeholders if accompanied by strong efficacy and improvement in HRQoL. Given the inability to measure cough frequency in clinical practice, Patient-Reported Outcomes (PROs) could be considered a proxy of treatment effectiveness. A multidisciplinary approach to the condition is regarded as key for treatment success.

CONCLUSIONS

Refractory or unexplained chronic cough is a medical condition that seriously impacts patients' HRQoL. The primary goal of treatment is to improve patients' HRQoL by reducing the frequency and intensity of cough.

Unmet needs in treating laryngo-pharyngeal reflux disease: where do we go from here?

INTRODUCTION

Many patients experience ear, nose and throat symptoms associated with their gastroesophageal reflux disease. These symptoms are purportedly caused by reflux of gastroduodenal contents into the larynx, which leads to laryngopharyngeal reflux (LPR). Various modalities are used to diagnose LPR, including ambulatory pH monitoring, laryngoscopy, and esophagogastroduodenoscopy, as well as a few new emerging diagnostic tests. However, there are still no established diagnostic criteria or gold standard methodologies that can reliably distinguish LPR from other conditions.

AREAS COVERED

In this review, we will evaluate currently available diagnostic tests and therapeutic options for patients with laryngeal signs and symptoms of reflux and briefly discuss the development and emergence of new treatments. Numerous studies have investigated the role of proton pump inhibitor therapy in this patient population, but have led to disparate and often inconsistent results. Expert commentary: While a subgroup of patients with LPR appears to respond to PPI therapy, many patients show no symptomatic improvement, particularly with respect to extraesophageal symptoms. As such, there is a vital need to explore alternative treatment options, including anti-reflux surgery, lifestyle changes, and other classes of medications to better address LPR.

Viral laryngitis: a mimic and a monster - range, presentation, management

PURPOSE OF REVIEW

The purpose of this review is to highlight recent literature relating to the diagnosis and treatment of some less common forms of viral laryngitis. The main conditions addressed in this review are chronic cough or postviral vagal neuropathy, varicella zoster infection of the larynx, and a condition increasingly suspected as being virally induced, idiopathic ulcerative laryngitis.

RECENT FINDINGS

Diagnosis of these conditions requires a thorough history and physical exam, and in certain cases referral to other subspecialties such as gastroenterology and pulmonology. Chronic cough due to postviral vagal neuropathy is a diagnosis of exclusion; however, recent literature does suggest that certain studies such as laryngeal electromyography can be of use in reaching a diagnosis. Treatment of this neuropathy has focused on use of neuromodulators. Treatment of laryngeal shingles and idiopathic ulcerative laryngitis has not been well defined because of the rarity of these conditions.

SUMMARY

Recent studies regarding these conditions and potential future treatment options will be discussed.

A review on the efficacy and safety of gabapentin in the treatment of chronic cough

INTRODUCTION

Effective antitussives available to control cough are limited. Consolidation among different afferent branches of the vagus nerve is needed to bring about cough. A general, widely accepted view is that the chronic increase in the sensitivity of the cough reflex is associated with inflammatory hypersensitivity such as from gastro-esophageal reflux disease. There is increasing evidence that an important mechanism is a sensory disorder of the laryngeal branches of the vagus nerve. Neuromodulating drugs are effectively used in the treatment of chronic pain and neuropathic disorders and may have a role in the treatment of refractory chronic cough (CC).

AREAS COVERED

Current evidence on the efficacy and safety of gabapentin in the treatment of CC is reviewed. Relevant randomized controlled trials, case reports and reviews were identified through a PubMed search of English-language literature referring to cough, sensory neuropathy and gabapentin over the last 10 years.

EXPERT OPINION

Gabapentin appears to be effective and well tolerated in the treatment of CC and in other sensory neuropathic disorders. Relevant clinical trials investigating its efficacy and safety profile in the treatment of cough are limited and further studies are needed. Gabapentin has been shown to cause minimal to no toxicity in overdose.

Advances in understanding pathogenesis of gastroesophageal reflux-related cough

Gastroesophageal reflux-related cough (GERC) refers to chronic cough caused by gastroesophageal reflux disease (GERD) and is one of the common causes of chronic cough in adults. Compared with typical GERD, GERC has its own characteristics in the pathogenesis of cough. The main mechanisms involve direct refluxate stimulation and indirect esophageal-bronchial reflection. In addition, the high sensitivity of cough receptors, acid-producing bacteria, nongastric H⁺/K⁺-ATPases and psychological factors are also important in the pathogenesis of GERC. GERC may be the result of the combined effects of multiple factors.

Cough in children

Cough during childhood is very common, and is one of the most frequent reasons for consultation in daily pediatric practice. The causes differ from those in adults, and specific pediatric guidelines should be followed for correct diagnosis and treatment. The most common cause of cough in children is viral infection producing "normal cough", but all children with persistent cough, i.e. a cough lasting more than 4-8weeks or "chronic cough", must be carefully evaluated in other to rule out specific causes that may include the entire pediatric pulmonology spectrum. The treatment of cough should be based on the etiology. Around 80% of cases can be diagnosed using an optimal approach, and treatment will be effective in 90% of them. In some cases of "nonspecific chronic cough", in which no underlying condition can be found, empirical treatment based on the cough characteristics may be useful. There is no scientific evidence to justify the use of over-the-counter cough remedies (anti-tussives, mucolytics and/or antihistamines), as they could have potentially serious side effects, and thus should not be prescribed in children.