Bowel function during pain therapy with oxycodone/naloxone prolonged-release tablets in patients with advanced cancer

BACKGROUND: The World Health Organization (WHO) step-III opioids are often required right from the start of pain therapy in order to achieve sufficient symptom control. Bowel dysfunction, particularly constipation, is one of the most frequent and persistent side effects of opioid therapy, and it is known to cause considerable distress in many patients. The aim of the study was to evaluate whether patients with advanced cancer and moderate to severe cancer pain will benefit from treatment with oxycodone/naloxone prolonged-release tablets (OXN), with particular regard to constipation.

MATERIAL AND METHODS: In this exploratory, non-randomised, open-label, mono-centre study we evaluated the bowel function in palliative care patients treated with OXN. During the treatment phase patients were titrated up to an adequate pain control. The Bristol Stool Form Scale (BSFS) (type 1-7) and Bowel Function Index (BFI) (0-100) were used to assess consistency and frequency of bowel movements. Global patient satisfaction was assessed with Patient Global Impression of Change Scale (PGIC) (1-7).

STATISTICS: mean ± SD, significance p<0.05.

RESULTS: Twenty-six patients [10 male patients (38.5%)] were included; mean age 70.6 ± 14.0 years, length of stay 22.6 ± 21.2 days. At admission all patients had opioid-induced constipation. During the observation period of 14 days the daily mean dose of OX was 36.2 ± 17.2 mg and of N 15.4 ± 5.3 mg. In five cancer patients pain control was not sufficient under the approved maximum total daily dose of 40/20 mg OXN; therefore switching to hydromorphone. BFI improved significantly in 21 patients (72.4 ± 17.0 vs. 36.8 ± 13.4) (p<0.0001); stool consistency (BSFS) improved from type 2.0 ± 0.7 to 4.9 ± 1.0 (p<0.0001). PGIC at discharge was 1.9 ± 0.8.

DISCUSSION: Patients with OXN treatment throughout the whole study phase showed a clinically relevant improvement in pain intensity and bowel function as well as increased satisfaction. Well-known disadvantages of laxative treatment might be spared or even circumvented under OXN treatment, if appropriate.