Cough in palliative care patients is often caused by infection, pleural effusion, or the direct effects of malignancy on the lung or airways. Co-morbidities such as Chronic Obstructive Pulmonary Disease (COPD) and cardiac failure may also contribute, and should be optimised. Antibiotic treatment of infection may sometimes give good palliation of infected secretions.
The investigation and management of cough may differ depending on the person’s illness stage and wishes for treatment. Active treatment of malignancy as appropriate with surgery, chemotherapy or radiotherapy, or by drainage of pleural effusion, may effectively treat coughing in patients who are well enough.  The following information relates to the symptomatic management of cough.
What is known
There is little evidence to support the use of the most common medications that are used to suppress coughing in palliative care patients, nor have they been studied in the palliative care population. [1-3] Most commonly used are weak opioids (as in over the counter cough syrups) and strong opioids (morphine and other opioid agonists) or antitussives containing dextromethorphan, which which have low level evidence of efficacy [1,4]. Other agents studied include levodropropizine , sodium cromoglycate and butamirate citrate linctus (cough syrup) . Overall, no agent can be clearly recommended as an effective antitussive.
There is some evidence to support the use of mucolytic agents in COPD, however they have not been studied in the palliative care setting. 
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. 
What it means in practice
- 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. 
- Management of secretions can involve antimuscarinic medications and / or, when appropriate, antibiotics.
- A moist cough in a dying patient can be managed with antimuscarinic medications. Treatment of mucopurulent sputum with antibiotics may sometimes provide palliation by reducing the volume of secretions and cough.