
    'recruitment not possible given changes to trial criteria
  
['chronic obstructive pulmonary disease', 'dyspnea']
['morphine sulfate', 'placebo']

        Inclusion Criteria:

          -  18 years of age or older.

          -  Physician diagnosed COPD confirmed by spirometry, defined as a prior
             post-bronchodilator FEV1/FVC < 0.7 in accordance with the GOLD 2014 criteria

          -  On stable medications relating to the optimal treatment of COPD or its symptomatic
             management over the prior week except routine "as needed" medications.

          -  Breathlessness of a level two (2) or higher on the modified Medical Research Council
             (mMRC) dyspnoea scale

          -  English speaking with sufficient reading and writing ability to complete the study
             questionnaires

          -  Assessed as competent (using SLUMS score of 27 for high school, and 25 for less than
             high school)

          -  Able and willing to give written informed consent

        Exclusion Criteria:

          -  On regularly prescribed opioid medications, including codeine preparations at or above
             8mg oral morphine equivalent daily in the previous seven (7) days.

          -  History of adverse reactions to any of the study medications or constituents in the
             placebo;

          -  Australian-modified Karnofsky performance score (AKPS) less than 50 at the beginning
             of the study.

          -  Respiratory or cardiac event in the previous one week (excluding upper respiratory
             tract infections). Illness must have resolved completely prior to baseline evaluation,
             as judged by the person's treating physician.

          -  Evidence of respiratory depression with resting respiratory rate <8/min.

          -  Documented central hypoventilation syndrome.

          -  Chronic alcoholism, or previous or recent history of substance misuse.

          -  Uncontrolled nausea, vomiting or evidence of a gastrointestinal tract obstruction.

          -  Renal dysfunction with creatinine clearance calculated (MDRD) less than 20 mls/minute.

          -  Evidence of severe hepatic impairment defined as transaminases or bilirubin >4x normal
             (Excluding Gilbert's syndrome)

          -  Pregnant or breastfeeding.
      