Levorphanol as a Second Line Opioid in Cancer Patients Presenting to an Outpatient Supportive Care Center: An Open-label Study.

Context: Levorphanol is a potent opioid agonist and NMDA receptor blocker with minimal drug interactions, and there are few reports of its use in cancer patients.

Objectives: We aimed to determine the frequency of successful opioid rotation (OR) to levorphanol and the median opioid rotation ratio (ORR) from Morphine Equivalent Daily Dose (MEDD).

Methods: This is a prospective, single-group, interventional study. Cancer outpatients requiring an OR and receiving a MEDD of 60-300 mg were rotated to levorphanol using a ratio of 10:1 and assessed daily for 10-day. Successful OR was defined as a 2-point improvement in the Edmonton Symptom Assessment System (ESAS) pain score on day 10 or achieving the personalized pain goal between days 3-10 in patients with uncontrolled pain or resolution of opioid side effects (OSE) in those undergoing OR for OSE alone. The ORR to levorphanol was calculated using net-MEDD (MEDD before OR minus the MEDD of the breakthrough opioid used along with levorphanol after OR).

Results: Forty patients underwent OR to levorphanol, and uncontrolled pain 35/40 (87.5%) was the most common indication. The median net-MEDD and levorphanol doses were 95 and 10 mg, respectively, and 33/40 (82.5%) had a successful OR with a median (IQR) ORR of 8.56 (7.5-10). Successful OR was associated with significant improvement in ESAS and OSE scale scores. There was a strong association between MEDD and levorphanol dose.

Conclusion: This study provided preliminary data that cancer patients could be successfully rotated to levorphanol using an ORR of 8.5. Levorphanol was associated with improved pain and symptom control and was well- tolerated.