Drug products: Lindoxa, Oxikodon Actavis, Oxikodon Depot Acino, Oxikodon Depot Actavis, Oxikodon Depot Evolan, Oxycodon Ratiopharm, Oxycodone Depot 1A Farma, Oxycodone Depot Lannacher, Oxycodone Depot Orion, Oxycodone Depot Teva, Oxycodone G.L., Oxycodone Hameln, Oxycodone Orion, Oxycodone Teva, Oxycodone Vitabalans, Oxyconta Depot, OxyContin®, Oxydorine Depot, OxyNorm®
ATC code: N02AA05
Substances: oxycodone, oxycodone hydrochloride
Published controlled studies on differences between men and women in effect of oxycodone are lacking. Pharmacokinetic studies show conflicting results. Retrospective studies on the analgetic effect of oxycodone has shown that men receive higher doses than women.
The scientific literature indicates that pain behavior and pain perception may vary between men and women. This could be influenced by differences in pharmacokinetics, sex hormones, differences in stress response, or type of pain test. Also, many variables other than a person’s sex/gender account for individual differences in pain sensitivity. The prevalence of several clinical pain conditions is higher in women than in men, which suggests that either different clinical pain mechanisms may operate in men vs. women, or different or additional risk factors are relevant in one sex, or a combination of differences [1-3]. Therefore, sex differences of pain releasing medication might thus be difficult to interpret .
Studies on sex differences in oxycodone pharmacokinetics show contradictory results. A pharmacokinetic study (247 men, 192 women) showed that male cancer patients had about 30% higher serum concentrations of oxycodone than female patients but the doses in men were higher (80 mg/day vs. 70 mg/day). It is suggested that the higher body weight of men can’t account for this differences since dosing for cancer pain is not based on weight. A possible explanation may be that men are less sensitive to opioids and therefore require higher doses to relieve similar levels of pain .Women had higher levels of the active metabolite oxymorphone and the inactive metabolites noroxymorphone, and noroxycodone but lower concentrations of the parent substance oxycodone than men. Similar findings have been observed in another study . The metabolism of oxycodone is primarily through CYP3A4, which activity is higher in women .Another study (14 men, 14 women) found no significant differences in mean oxycodone AUC and Cmax between men and women after a single 20 mg oral oxycodone dose. When adjusting for bodyweight, women eliminated oxycodone 25% more slowly than men. However, women had lower mean AUC and Cmax of the active metabolite oxymorphone. This suggests that the metabolism of oxycodone to oxymorphone is based on sex .
Despite the pharmacokinetic differences of oxycodone, the clinical studies have shown effect with similar doses in men and women and no sex differentiation in dosing has been suggested . Factors influencing of opioid doses prescribed to cancer patients have been analyzed retrospectively according to pharmacy records in North America (3631 men, 3570 women). Patients received sustained-release morphine, sustained-release oxycodone, or transdermal fentanyl. Sustained-release doses were converted to OME (oral morphine equivalent). The mean opioid dose was 142.4 mg/day for women and 157.4 mg/day for men. However, when controlling for age and primary tumor site, this differences was not significant .
The efficacy of oxycodone has been evaluated in an open-label study based on a questionnaire to young and elderly men and women (14 men, 14 women) receiving 20 mg oxycodone. Women had a greater feeling of drug effect than men .
An observational study of elderly people (520 men, 827 women, mean age 73 years) has shown that postoperative nausea and vomiting are more common in women (+91%) . Also, a study on postoperative oxycodone-induced nausea and emesis has shown this to be higher in women than in men . If this is due to the medication was not explored in these studies.In a randomized, double-blind, placebo-controlled trial, light drinkers (8 men, 7 women) and moderate drinkers (8 men, 6 women) received 0, 10 and 20 mg of oral oxycodone. Women treated with 20 mg oxycodone reported more frequent and pronounced adverse effects (dizziness, nausea, vomiting etc.) than men. A suggested explanation was that oxycodone was not adjusted for body weight, and since men weighed more than women in this study, women got higher doses than men .
Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).
Date of litterature search: 2015-01-30
Reviewed by: Mia von Euler
Approved by: Karin Schenck-Gustafsson