Analgesic Plasma Concentrations of Oxycodone After Surgery for Breast Cancer—Which Factors Matter?

Abstract

We investigated factors affecting analgesic oxycodone concentrations after breast cancer surgery in 1,000 women. Preoperatively, we studied heat and cold pain sensitivities and anxiety scores. Postoperatively, rest and motion pain intensities were measured and intravenous oxycodone was administered until satisfactory analgesia. At this point, the mean oxycodone concentration (variation coefficient) was 33.3 ng/mL (66%) and it was 21.7 ng/mL (69%) when the patient requested oxycodone again. At both time points, the concentrations varied >100-fold between individuals. The analgesic oxycodone concentration was increased by 21.3% per motion pain intensity score on a 0-10 scale and by 22.3% if axillary clearance was performed instead of sentinel node biopsy (P < 0.001). Forty-seven women who were older and less anxious than others (P < 0.01) required no oxycodone. Anxiety, age, chronic pain, or preoperative pain sensitivity were not independently associated with the analgesic oxycodone concentration. CYP2D6 and CYP3A genotypes did not affect analgesic concentration or duration of analgesia.

Genetics and genomics in postoperative pain and analgesia

“…In general, the main predictive factor for postoperative pain is type of surgery [56]. Other major factors include preoperative pain, anxiety and age [8,56]. On an individual basis, genetic variation may play a significant role in pain intensity and treatment outcome.…”

Updated Clinical Pharmacokinetics and Pharmacodynamics of Oxycodone

“…In breast surgery, the extent of surgery seems to affect the need for oxycodone. Cajanus et al [103] evaluated the MEC of oxycodone after breast cancer surgery. In patients who did not need axillary evacuation, MEAC was 29 ng/mL, and 39 ng/mL with axillary evacuation; however, the extent of interindividual variation in the MEAC values was excessive (range between < 0.1 and 311 ng/mL) [103].…”

“…Cajanus et al [103] evaluated the MEC of oxycodone after breast cancer surgery. In patients who did not need axillary evacuation, MEAC was 29 ng/mL, and 39 ng/mL with axillary evacuation; however, the extent of interindividual variation in the MEAC values was excessive (range between < 0.1 and 311 ng/mL) [103]. CYP2D6 and CYP3A4/5 polymorphisms and OPRM1 c.118A > G did not affect the analgesic concentration of oxycodone or the duration of analgesic action [104].…”

Electrochemical Detection of Oxycodone and Its Main Metabolites with Nafion-Coated Single-Walled Carbon Nanotube Electrodes

“… 1 The pharmacokinetic profile of oxycodone is affected by several factors such as age, sex, concomitant diseases, and drug–drug interactions. 2 In addition, the plasma concentrations of oxycodone leading to sufficient analgesia after surgery are highly individual, the average concentrations ranging between 0.3 and 100 nM, 3 and in cases of overdose, the highest concentrations found in blood can be over 10 μM. 4 Thus, there is need for a fast and accurate method to assess the blood concentrations of oxycodone to support safe and efficacious pain management and enable rapid diagnostics of opioid overdosing.…”