Mazzocato, C., Buclin, T., & Rapin, C.H. (1999). The effects of morphine on dyspnea and ventilatory function in elderly patients with advanced cancer: A randomized double-blind controlled trial. Annals of Oncology, 10(12), 1511–1514.

Subcutaneous (SC) morphine 5 mg or placebo in opioid-naïve patients and regular oral morphine dose plus half of the every-four-hour (q4h) dose given SC in patients on regularly scheduled opioids

• The sample was comprised of nine patients (seven opioid naïve and two opioid tolerant).
• Mean patient age was 73 years.
• The sample included four women with advanced cancer and dyspnea resulting from lung involvement.
• All patients had normal Mini-Mental Status Examinations (MMSEs).

The study was conducted in an inpatient geriatric hospital.

The study was a double-blind, placebo controlled, randomized, cross-over trial.

• Dyspnea visual analogue scale (VAS) (100 mm) and Borg scale obtained at baseline and 45 minutes after SC study dose and repeated until 240 minutes
• VAS for pain, somnolence, and anxiety
• Respiratory effort, including rate, cyanosis, and use of accessory muscles
• Pulse oximetry

• Mean change of VAS (–25, p < 0.01) and Borg scale (–1.20, p = 0.03) scores were significantly decreased with morphine compared to placebo.
• Respiratory effort (p = 0.05) and rate (p = 0.02) scores were significantly improved after morphine compared to placebo.
• No significant changes in pain, somnolence, anxiety, or oxygen percent saturation were found.

Intermittent injections of morphine at the doses used reduce cancer-related dyspnea. The changes in respiratory effort and rate but not anxiety support the theory that the benefit of morphine is unlikely related to somnolence or an effect on anxiety.

• This is a well-designed randomized, controlled study with the major limitation of sample size.
• The study points out the difficulty in conducting pharmacologic studies in patients with cancer and dyspnea.