Efficacy and Safety of Two Methadone Titration Methods for the Treatment of Cancer-Related Pain: The EQUIMETH2 Trial (Methadone for Cancer-Related Pain).

ABSTRACT

CONTEXT In the European Association for Palliative Care recommendations for cancer pain management, there was no consensus regarding the indications, titration, or monitoring of methadone. OBJECTIVES: This national, randomized, multicenter trial aimed to compare two methadone titration methods (stop-and-go vs. progressive) in patients with cancer-related pain who were inadequately relieved by or intolerant to Level 3 opioids. METHODS: The primary end point was the rate of success/failure at Day 4, defined as pain relief (reduction of at least two points on the visual scale and a pain score <5 for two consecutive days) and no overdose (Rudkin scale ≥3 and respiratory rate <8/minute). The patients were followed for two months after enrollment. RESULTS: The cancer-related pain characteristics of the 146 patients were as follows 16% were nociceptive, 85% experienced breakthrough pain, and 84% had mixed types of pain. The reasons for switching to methadone were a lack of efficacy that was either isolated (56%) or associated with intolerance (38%). Adequate pain relief was obtained in 80% of the patients (median of three days in both groups [P = 0.12]) and lasted until D56. The rate of success/failure was approximately 40% at Day 4 in both groups, with overdoses in 13% of the patients throughout the study. The two methods were considered equally easy to perform by nearly 60% of the clinicians. CONCLUSION: Methadone is an effective and sustainable second-line alternative opioid for the treatment of cancer-related pain. The methods of titration are comparable in terms of efficacy, safety, and ease of use.