| Morphine/morphine metabolite sub-study |
55 |
Aim: to determine the relationship between the steady-state plasma concentrations of M3G and M6G along with the effects of renal function with change in breathlessness intensity Blood samples collected at baseline and steady state at trough levels end of week 1 and week 3
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| Pharmacogenetic substudy |
All consenting |
Aim: identification and assessment of genetic variations in opioid receptor, neuronal, immune, metabolic or signalling pathways that may influence clinical responsiveness to ER morphine for symptomatic treatment of chronic breathlessness Blood sample collection at baseline
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| Sleep substudy |
30
20 |
Aim: to investigate the effect that study interventions have on sleep quality Data obtained from Fitbit Charge HR for all participants Thirty participants recruited to non-invasive, home-based sleep studies at baseline and at the end of stage 3 Up to 20 participants from two centres (Sydney and Adelaide) will participate in two formal overnight laboratory sleep studies at baseline and at the end of stage 3.
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| Driving substudy |
20 |
Aim: assess effects of introducing and steady-state ER morphine use on driving simulator performance in subgroup of participants Short questionnaire to assess driving history Participants from two centres (Sydney and Adelaide) will complete three 30 min office-based driving simulations. One at baseline, one on day 2 and again on day 7 of stage 1.
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| Caregiver well-being substudy |
All consenting |
Aim: to compare the impact on caregiver well-being between study interventions when compared with baseline Caregivers asked to provide basic demographic data and complete the Zarit burden interview 12-item short-form questionnaire133
Assess level of subjective burden at baseline and the end of stages 1, 2, 3 and 4 (or study withdrawal)
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| Patient and caregiver qualitative substudy |
All consenting |
Aim: to understand the experience of living with chronic breathlessness and the attitudes towards ER morphine use for its symptomatic treatment Limited to participants from Adelaide Separate patient and caregiver qualitative interviews People who decline to participate in the BEAMS study but who fulfil the inclusion criteria will also be offered participation in this substudy.
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| Economic analysis substudy |
All consenting |
Aim: to compare within trial incremental costs and cost effectiveness of regular low-dose ER morphine using prospectively collected data Data collected will include hospitalisations, presentations to emergency departments, use of primary care, allied health practitioners and palliative care services throughout the study and for 4 weeks after last study medication is given.
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| Testosterone level substudy |
All consenting from stage 4 |
Aim: to further evaluate changes in total testosterone levels given concerns in previous studies that suggest morphine may reduce testosterone levels134 135
Prospectively obtained blood samples at baseline and on completion of stage 4
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| Cortisol substudy |
All consenting (who have not been on glucocorticoids in the preceding 4 weeks) |
Aim: to understand if hypothalamic–pituitary–adrenal axis dysregulation of chronic disease is influenced by reduction in chronic breathlessness as a stressor, with some return of normal diurnal variation. Saliva tests three times each of 8 days across the study.
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