Pediatric Development of BosentanMarch 10, 2018
Plasma Concentration of OxycodoneApril 16, 2018
Analgesic plasma concentrations of oxycodone after surgery for breast cancer
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). 47 women, 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.