Tapentadol in Cancer Patients with Neuropathic Pain: A Comparison of Methadone, Oxycodone, Fentanyl, and Hydromorphone.

ABSTRACT

Tapentadol has µ-opioid receptor stimulating and noradrenaline reuptake inhibiting properties, and should be effective for neuropathic pain (NP). However, the efficacy of tapentadol for NP in cancer patients is unclear. Ashiya Municipal Hospital (Hyogo, Japan) enrolled five groups of Japanese cancer patients between January 1, 2013, and December 31, 2019. Patients with NP were administered tapentadol (n = 29), methadone (n = 32), oxycodone (n = 20), fentanyl (n = 26), or hydromorphone (n = 20). The primary endpoint was the difference in the verbal rating scale (VRS) scores between days 0 and 7. The secondary endpoint was the tolerability of each opioid. Before administering opioids among the five groups, there was no significant difference in the VRS score (p = 0.99). The mean reduction in the VRS score on day 7 was significantly greater in the tapentadol group than in the oxycodone group (p = 0.0024) and was larger than that of the methadone, fentanyl, and hydromorphone groups. Regarding safety, the discontinuation rate in the tapentadol group was the lowest of all groups (tapentadol vs. methadone vs. oxycodone vs. fentanyl vs. hydromorphone, 0.0% vs. 6.3% vs. 5.0% vs. 3.8% vs. 10.0%, respectively). This study suggests that tapentadol could be efficacious for cancer patients with NP, and a preferred option in cases that require immediate dose adjustment or for those at high risk for adverse effects. However, the pain intensity was evaluated without pain assessment scales specific to NP. Thus, we think that it is desirable to validate our findings using assessment scales, such as the painDETECT questionnaire in future.