Morphine for treatment of cough in idiopathic pulmonary fibrosis (PACIFY COUGH): a prospective, multicentre, randomised, double-blind, placebo-controlled, two-way crossover trial.

BACKGROUND: Idiopathic pulmonary fibrosis is a progressive fibrotic lung disease, with most patients reporting cough. Currently, there are no proven treatments. We examined the use of low dose controlled-release morphine compared with placebo as an antitussive therapy in individuals with idiopathic pulmonary fibrosis. METHODS: The PACIFY COUGH study is a phase 2, multicentre, randomised, double-blind, placebo-controlled, two-way crossover trial done in three specialist centres in the UK. Eligible patients aged 40-90 years had a diagnosis of idiopathic pulmonary fibrosis within 5 years, self-reported cough (lasting >8 weeks), and a cough visual analogue scale (VAS) score of 30 mm or higher. Patients were randomly assigned (1:1) to placebo twice daily or controlled-release morphine 5 mg orally twice daily for 14 days followed by crossover after a 7-day washout period. Patients were randomised sequentially to a sequence group defining the order in which morphine and placebo were to be given, according to a computer-generated schedule. Patients, investigators, study nurses, and pharmacy personnel were masked to treatment allocation. The primary endpoint was percentage change in objective awake cough frequency (coughs per h) from baseline as assessed by objective digital cough monitoring at day 14 of treatment in the intention-to-treat population, which included all randomised participants. Safety data were summarised for all patients who took at least one study drug and did not withdraw consent. This study was registered at ClinicalTrials.gov, NCT04429516, and has been completed. FINDINGS: Between Dec 17, 2020, and March 21, 2023, 47 participants were assessed for eligibility and 44 were enrolled and randomly allocated to treatment. Mean age was 71 (SD 7·4) years, and 31 (70%) of 44 participants were male and 13 (30%) were female. Lung function was moderately impaired; mean forced vital capacity (FVC) was 2·7 L (SD 0·76), mean predicted FVC was 82% (17·3), and mean predicted diffusion capacity of carbon monoxide was 48% (10·9). Of the 44 patients who were randomised, 43 completed morphine treatment and 41 completed placebo treatment. In the intention-to-treat analysis, morphine reduced objective awake cough frequency by 39·4% (95% CI -54·4 to -19·4; p=0·0005) compared with placebo. Mean daytime cough frequency reduced from 21·6 (SE 1·2) coughs per h at baseline to 12·8 (1·2) coughs per h with morphine, whereas cough rates did not change with placebo (21·5 [SE 1·2] coughs per h to 20·6 [1·2] coughs per h). Overall treatment adherence was 98% in the morphine group and 98% in the placebo group. Adverse events were observed in 17 (40%) of 43 participants in the morphine group and six (14%) of 42 patients in the placebo group. The main side-effects of morphine were nausea (six [14%] of 43 participants) and constipation (nine [21%] of 43). One serious adverse event (death) occurred in the placebo group. INTERPRETATION: In patients with cough related to idiopathic pulmonary fibrosis, low dose controlled-release morphine significantly reduced objective cough counts over 14 days compared with placebo. Morphine shows promise as an effective treatment to palliate cough in patients with idiopathic pulmonary fibrosis, and longer term studies should be the focus of future research. FUNDING: The Jon Moulton Charity Trust.

PAciFy Cough-a multicentre, double-blind, placebo-controlled, crossover trial of morphine sulphate for the treatment of pulmonary Fibrosis Cough.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive disease that leads to lung scarring. Cough is reported by 85% of patients with IPF and can be a distressing symptom with a significant impact on patients' quality of life. There are no proven effective therapies for IPF-related cough. Whilst morphine is frequently used as a palliative agent for breathlessness in IPF, its effects on cough have never been tested. PAciFy Cough is a multicenter, double-blind, placebo-controlled, crossover trial of morphine sulphate for the treatment of cough in IPF. METHODS: We will recruit 44 subjects with IPF prospectively from three interstitial lung disease units in the UK, namely the Royal Brompton Hospital, Manchester University NHS Foundation Trust (MFT) and Aintree University Hospital NHS Foundation Trust. Patients will be randomised (1:1) to either placebo twice daily or morphine sulphate 5 mg twice daily for 14 days. They will then crossover after a 7-day washout period. The primary endpoint is the percent change in daytime cough frequency (coughs per hour) from baseline as assessed by objective cough monitoring at day 14 of treatment. DISCUSSION: This multicentre, randomised trial will assess the effect of opioids on cough counts and cough associated quality of life in IPF subjects. If proven to be an effective intervention, it represents a readily available treatment for patients. TRIAL REGISTRATION: The study was approved by the UK Medicines and Healthcare Regulatory Agency (Ref: CTA 21268/0224/001-0001 - EUDRACT 2019-003571-19 - Protocol Number RBH2019/001) on 08 April 2020, in compliance with the European Clinical Trials Directive and the Medicines for Human Use (Clinical Trials) Regulations 2004 and its subsequent amendments. The study was provided with ethical approval by the London Brent Research Ethics Committee (Ref: 20/LO/0368) on 21 May 2020 and is registered with clinicaltrials.gov (NCT04429516) on 12 June 2020, available at https://clinicaltrials.gov/ct2/show/NCT04429516.