Article of the Month
by Carla Ripamonti, MD (Italy)

NORMAL- RELEASE ORAL MORPHINE STARTING DOSE IN CANCER PATIENTS WITH PAIN.

Ripamonti, C et al. Clin J Pain 2009; 25 (5) 386-90

In the treatment of cancer-related pain, morphine is considered to be the gold standard among opioid analgesics and is on the Essential Drug List of the World Health Organization for the management of patients with cancer-related pain.

The authors report a prospective uncontrolled phase IV study to evaluate the efficacy and suitability in clinical practice of starting with a fixed dose of normal-release morphine (NRM) that is determined by the nature of the previous analgesic treatment.

The current recommendations of the European Association for Palliative Care (EAPC) were considered. NRM sulphate oral solution was administered every 4 hours to opioid naïve patients (group A, at 5 mg) and to patients already being treated with “weak” opioids (group B, at 10 mg).

A secondary aim was to estimate the percentage of patients who were high responders to NRM and to study the association of baseline patient characteristics with both high analgesic responsivity and the need of opioid dose escalation.

Sixteen palliative care centers were involved and 151 patients were enrolled. Among the patients on a pain treatment, 45 patients (30%) (Group A) were on NSAIDs and received 5mg/4 h of NRM and 106 patients (70%) (Group B) were on “weak” opioids and they received 10 mg/4 h of NRM.

A significant reduction in pain score both after 3 and 5 days from baseline (p<0.001) was shown in both groups. On an average the OEIs were: 3.2 in group A and 6.5 in group B; OEI was 3 times higher in patients with neuropathic pain. In multivariate analysis both KPS and episodic pain showed to be independent prognostic factors of a high analgesic response.

These results show that using an empiric standard dose, as recommended by EAPC, for titration with NRM at either 5 or 10 mg every 4 hours that is based on the type of prior therapy is effective in clinical practice. Therapy has to be monitored daily to maintain adequate pain control. Moreover, NRM is also effective in treating neuropathic pain even if higher doses are needed.