Opioids bring peace to patients with IPF cough

There are now two positive, randomised, placebo-controlled phase 2 trials of opioid treatment for cough in patients with idiopathic pulmonary fibrosis (IPF). Opioids suppress cough by binding to several types of G protein-coupled endorphin receptors on presynaptic neurons in brainstem cough centres, thus modulating neurotransmitter release. A trial of nalbuphine, a mixed agonist–antagonist of opioid receptors, showed a 52·5% placebo-adjusted reduction in daytime cough counts.1 In The Lancet Respiratory Medicine, Zhe Wu and colleagues2 report results from PACIFY-COUGH, showing that 2 weeks' treatment with twice daily low-dose morphine significantly reduced objective awake cough frequency (by 39·4%, 95% CI –54·4 to –19·4; p=0·0005) compared with placebo.