Cough

Evidence summary

Cough in palliative care patients is often associated with infection (acute and chronic), aspiration, gastroesophageal reflux, pleural effusion, or the direct effects of malignancy on the lung or airways. Cough is a common symptom in Chronic Obstructive Pulmonary Disease (COPD), Interstitial Lung Disease and may be a feature of cardiac failure. The investigation and management of cough may differ depending on the person’s illness stage and wishes for treatment but identifying the underlying cause of the cough is essential. [1] While coughing serves as a protective mechanism to clear secretions or maintain airway patency, persistent cough can exacerbate breathlessness, increase fatigue and pain. [2] Once disease related treatments have been optimise, or if no clear underlying cause has been identified, treatment of persistent cough should be focused on symptom management.

Pharmacological interventions for chronic cough used in palliative care are based on research undertaken with different patient groups. [2,3] Opioid antitussives have been examined by a number of reviews and no one opioid has been recommended as superior for use. [2,4] Codeine is now not recommended for children under the age of 12 or those under 18 with respiratory conditions. [5] Non-opioid antitussives have also been examined including dextromethorphan. [4] Overall, no agent can be clearly recommended as an effective antitussive.

There is some evidence to support the use of protussives in COPD and other conditions where a high volume of sputum is produced, however they have not been studied in the palliative care setting. [4,6]

Antihistamines such as diphenhydramine, loratadine and levodropropizine have demonstrated some effectiveness in treating cough, although the evidence is of low quality. [2,4,5] Bronchodilators have also been shown to have some effect on cough and medications like sodium cromoglycate have also been effective in small clinical trials. [3,4] There is limited evidence to support inhaled corticosteroids for the management of persistent cough. [4]

Nebulised lignocaine or other local anaesthetics have sometimes been used empirically in palliative care patients with refractory cough. No high level evidence was found to support its use in the palliative care setting.

Brachytherapy shows promise as a treatment for cough in patients with lung cancer. Based on current evidence, the lowest effective dose should be used. [7,8] There is also some promising research on the use of gabapentin in persistent cough [1]

Practice implications

• Evidence based pragmatic recommendations for management of cough have been developed. Based on current low level evidence, the recommendations are to consider disease-directed treatment as appropriate, to attend to potentially reversible causes of cough, and to offer a simple cough linctus. Trial of sodium cromoglycate can be considered. Opioids including dextromethorphan, morphine or codeine should be tried if these measures are unsuccessful. [9]
• A moist cough in a dying patient can be managed with antimuscarinic medications, but there is low level evidence to support this. [10] Treatment of mucopurulent sputum with antibiotics may sometimes provide palliation by reducing the volume of secretions and cough. [11]