1479P - Use of rescue opioids and pain control after ketamine initiation in refractory cancer pain: A multicentric observational study

Background

Refractory cancer pain (RCP) affects 10-20% of cancer patients, exhibiting limited response to standard opioids (OPI). Ketamine (KET), an anesthetic medication, has gained recent attention for its potential in managing RCP. This study aims to describe the consumption of rescue OPI before and after initiating KET, the rate of patients meeting a controlled pain criteria, and its safety profile.

Methods

A prospective observational study was conducted in three academic hospitals. Over an 18-month period, we included all cancer patients who initiated KET therapy based on the criteria of their treating medical team. The frequency of OPI rescues was recorded on days five (D-5) and two (D-2), and on days two (D+2) and five (D+5) pre and post KET initiation, respectively. Controlled pain criteria were defined as a 72-hour interval with no more than 3 OPI rescues per day, absence of breakthrough pain, and no escalation in OPI dosage. All adverse effects (AEs) were recorded in accordance with the CTCAE 5.0 guidelines.

Results

Fifty-two patients were included, and their characteristics are described in the table. The most common initiation dose of KET was 0.5 mg/kg/day orally (71.2%). Median oral morphine milligram equivalent (MME) at initiation of KET was 120mg. Overall survival from the onset of KET therapy was 43 days. Median daily OPI rescue was 3.90 on D-5 and 4.62 on D-2, decreasing to 2.79 on D+2 and 2.77 on D+5 (p=

Conclusions

A significant decrease in rescue opioids usage was observed after initiating ketamine. Over 60% of the patients met the criteria for controlled pain, with a favorable safety profile. Further comparative studies are required to better understand the role of ketamine in cancer pain.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Vall d'Hebron University Hospital.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.