African Americans More Likely Than Whites to Receive Analgesic With Toxic Metabolite for Cancer Pain


Key Points

  • African Americans were significantly more likely to receive morphine.
  • In patients with chronic kidney disease, race was significantly associated with prescribed opioid and adverse effect severity.

A study reported by Meghani et al in the Journal of Clinical Oncology showed that African American patients with cancer pain are more likely than white patients to receive morphine, with its known 3- and 6-glucuronide neurotoxic metabolites, despite their higher reported risk for chronic kidney disease and associated risk of toxic metabolite accumulation.

Study Details

The study involved 182 patients from oncology clinics in the University of Pennsylvania Health System self-identified as African American (n = 73) or white (n = 109) who were aged ≥ 18 years and had cancer-related pain and a prescription for morphine or oxycodone. Kidney function was estimated by the abbreviated Modification of Diet in Renal Disease formula.

There was no difference between African American and white patients in age or renal status. African American patients belonged to a lower income bracket (P < .001) and were less likely to have private health insurance (P < .001). Chronic kidney disease defined as estimated glomerular filtration rate < 90 mL/min/1.73 m2 was present in 37% of African American and 51% of white patients.

Prescription Pattern and Adverse Effect Severity

Overall, African American patients were less likely to be prescribed oxycodone (53% vs 82%) and more likely to be prescribed morphine (47% vs 18%, P < .001), with this prescription pattern persisting among those with chronic kidney disease.

African American patients reported significantly greater cancer pain worst score (P < .001), pain least score (P < .001), and more severe analgesic adverse effects (P = .047). Patients with chronic kidney disease who received morphine reported a greater severity of analgesic adverse effects than those who received oxycodone (P = .010). There was no difference between African Americans and whites in severity of adverse effects among patients without chronic kidney disease (P = .841), but African American patients reported significantly greater severity among those with chronic kidney disease (P = .014).

Mediation Analysis

In analysis adjusting for health insurance type, African Americans had 71% lower odds of receiving a prescription of oxycodone (adjusted odds ratio [OR] = 0.29, P < .001. In analysis limited to patients with chronic kidney disease, the effect of private insurance became insignificant but race remained a significant predictor of the prescribed opioid (adjusted OR = 0.21, P = .0120).

Race was also a strong predictor of adverse effect severity among patients with chronic kidney disease (P = .0064). In a mediation analysis, the effect of opioid selection on adverse effect severity became statistically nonsignificant (P = .0932) but remained clinically meaningful, whereas race remained strongly associated with adverse effect severity (P = .0119).

The investigators concluded, “Reducing racial disparities in the type of opioid prescription and understanding mechanisms of disproportionate opioid-related adverse effects in African American patients might decrease the clinical disparities in cancer pain outcomes.”

Salimah H. Meghani, PhD, MBE, RN, FAAN, of University of Pennsylvania School of Nursing, is the corresponding author for the Journal of Clinical Oncology article.

The study was supported by a grant from the National Institutes of Health. Jeffrey Fudin, PharmD, FCCP, reported honoraria from Purdue Pharma.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.