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

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.

Efficacy and safety of methadone in the treatment of pain in palliative care patients with cancer: The EQUIMETH2 national, randomized, open, phase III study

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Background: Methadone is used more and more as a second-line treatment for refractory cancer pain in palliative care patients. Methods: The study aimed to compare the effect of two methadone titration methods (Stop and Go vs progressive titration) in 146 palliative care cancer patients with pain inadequately relieved or intolerant to level 3 opioids. The primary endpoint was the rate of success/failure at Day 4 defined by pain relief (reduction of at least two points of the numerical scale (0 - 10) AND a pain score < 5 for 2 consecutive days) AND no overdose (Rudkin scale ≥ 3 AND respiratory rate < 8/min). Results: Pain was nociceptive in 16% and mixed in 84%. 85% of the patients had breakthrough pain. Half received oxycodone, 1/5 fentanyl, 1/5 morphine and < 10% hydromorphone. Reasons for switching were lack of efficacy isolated (56%), or with intolerance to previous opioid (38%). More than 2/3 of the patients reached a pain score < 5 for two days at D4, adequate pain relief was obtained in 80% of the patients (median of 3 days in both groups (p = 0.12)) and lasted until D56. The rate of success/failure was about 40% at D4 with no difference between the two methods. Overdoses defined as respiratory rate < 8/min were observed in 13.2% patients throughout the study with no difference between groups. 9 required naloxone. The two methods were equally considered easy by about 60% of the clinicians. Conclusions: Methadone is an effective and sustainable second-line alternative opioid in the treatment of cancer pain in palliative care patients inadequately relieved or intolerant to level 3 opioids. The two methods of titration of methadone are comparable in terms of efficacy, safety and ease of use.