These results provide the first potential anatomical and functional explanation for sex differences in the experience of pain and responses to the drug morphine in the treatment of pain.
Morphine is currently the drug of choice for treating several types of post-operative pain, and it is becoming increasingly clear that morphine alleviates pain to a greater degree in males in comparison to females. The results of the study by Murphy and Loyd provide important details about how morphine might be used differently in females and males to achieve maximum pain relief.
Pain is one of the most common reasons that people consult physicians. Thus, the management of pain has become one of the highest priorities in health care. Chronic pain from inflammatory conditions such as arthritis and fibromyalgia are the most prevalent and pervasive forms of chronic pain.
Clinical evidence suggests that women are much more likely to experience chronic forms of pain than are men and that women report feeling more pain than men following various medical procedures.
Recent recommendations from the American Academy of Pain Medicine and the American Pain Society indicate that opioid drugs or "narcotics", such as morphine, are essential in the management of chronic pain. However, there is well-established clinical and nonclinical evidence that males and females do not respond the same to the effects of morphine. Specifically, females tend to require higher doses of morphine than males for pain relief following various medical procedures.