Simple linctus - which acts as a peripheral anti-tussive may help.
Nebulised saline - Use 2.5 –5ml of normal saline for injection in a standard nebuliser.
Short acting oral opioids – which act as a central anti-tussive may help some patients.
Oral steroids may help if there is associated lymphangitis. Starting dose 8mg dexamethasone as a single dose in the morning. Titrate downwards after one week to the minimum dose that controls the cough. If no effect after one week stop. Use appropriate GI protection using either a proton pump inhibitor or misoprostol in at risk patients.