Oral prolonged-release Oxycodone-Naloxone: analgesic response, safety profile, and factors influencing the response in advanced cancer patients.

BACKGROUND: Oxycodone-Naloxone (OXN) aims to reduce opioid-related constipation while being successfully analgesic. METHODS: We evaluated the analgesic response, prevalence, and severity of side effects in 176 cancer patients with moderate to severe pain and treated with OXN. Patients were followed for 28 days and evaluated every seven. Pain intensity, changes of therapy, and adverse drug reactions were recorded at each visit. The primary efficacy endpoint was the proportion of responders (≥30% reduction of pain intensity from baseline to final) and final average pain score ≤4 on a 0-10 scale. RESULTS: Average and worst pain intensity, and breakthrough pain (BTP) prevalence decreased over time and 81.3% of patients were responders. The starting daily dose of OXN was raised from 25.1±13.0 mg to 44.1±29.9 mg, and dose escalation >5%/day was observed in 19.4% of patients; 40.8-46.2% and 11.0-17.0% experienced any and severe grade of constipation during the follow-up visit, respectively. Digestive system tumor, thyroid endocrinopathies, psychological irritability, and BTP increased the risk of analgesic non-response. CONCLUSIONS: OXN had strong analgesic effect in moderate to severe cancer pain patients: the safety profile is in line with the common adverse effects of opioids and severe constipation was uncommon.