Quigley, C., Joel, S., Patel, N., Baksh, A., & Slevin, M. (2002). A phase I/II study of nebulized morphine-6-glucuronide in patients with cancer-related breathlessness. Journal of Pain and Symptom Management, 23, 7–9.

A single dose of nebulized morphine-6-glucuronide (M6G) (the active metabolite of morphine) was given to patients with cancer who had breathlessness. Three dose levels were studied:  5, 10, and 20 mg of M6G. The single dose of morphine was inhaled using an Acorn Porta-Neb jet nebulizer over 15 minutes.

• The sample was comprised of nine patients. 
• No patient characteristics were reported other than age (median = 51 years; range 45–77).
• Six patients were already receiving morphine.

• Unknown
• Results were reported from St. Bartholomew Hospital in London, United Kingdom.

This was an open, uncontrolled study that randomized patients to one of three dose levels.

• 100-mm visual analog scale (VAS) and modified Borg scale were used to quantify breathlessness, anxiety, and effort of breathing at pretreatment and at 15, 30, and 60 minutes posttreatment.
• VAS and verbal rating scales were used to assess nausea, drowsiness, and other side effects.

All patients reported a subjective improvement in breathlessness by the VAS and the Borg scale. A significant difference (p = 0.023) in dyspnea VAS was observed with time across all time points. No significant difference existed among the three treatment groups across all time points (p = 0.176), suggesting no difference among the three doses. A significant difference in dyspnea was found between patients. No significant changes existed in anxiety VAS and effort of breathing VAS with time or with dose. Minimal adverse effects were noted.

Nebulized M6G was relatively safe and possibly therapeutic in patients with cancer-related breathlessness.

• A small number of patients were studied.
• The study was reported as a letter to the editor.

A randomized study is planned.