Evaluation of the effectiveness and adverse events of oxycodone as a pain-relieving agent in 103 dogs with tumors: a retrospective study.

Background: Oxycodone, a semi-synthetic opioid, has been widely used in human medicine for the management of tumor-related pain due to its potent analgesic properties. This study aimed to evaluate the efficacy and safety of oxycodone in managing tumor-related pain in dogs, addressing the current lack of research on effective analgesic options for canine cancer dogs. Medical records of 103 tumor-bearing dogs treated with oxycodone were retrospectively reviewed.

Results: Oxycodone demonstrated an analgesic effect ranging from 23.1 to 63.6%, depending on the anatomical origin of the tumor. Improvement was observed in 67.7% of dogs with metastatic lesions. In the monotherapy group, the mean pain relief score increased from 8.73 ± 1.27 before treatment to 9.65 ± 1.53 after administration (p < 0.0001). In the combination therapy group, score rose from 8.75 ± 1.20 to 9.83 ± 1.87 (p = 0.0002). Across the entire canine patient cohort, the mean pain relief score increased from 8.74 ± 1.23 to 9.74 ± 1.70 following treatment (p < 0.0001). Adverse effects included lethargy (n = 6), diarrhea (n = 2), vomiting (n = 1), tachypnea (n = 1), and stargazing (n = 1). All were self-limiting and resolved after discontinuation of the drug.

Conclusions and clinical importance: Oxycodone demonstrated an overall favorable analgesic profile and could be a well-tolerated and promising pain management solution, both as monotherapy and in combination therapy, for tumor-related pain in dogs, including those with advanced-stage tumors.