Oxycodone (Oxaydo, Oxycontin, Roxicodone) is an opioid medication appropriate for the treatment of moderate to moderately severe pain, such as that from surgery or cancer, according to the American Pain Society. Opioid drugs bind to cells via specific opioid receptors, which are found primarily in the brain, spinal cord and digestive tract. When binding occurs, it sets off a series of changes within cells that go on to affect their metabolism. With exposure to oxycodone, metabolic changes in cell with opioid receptors leads to slowed activity of the brain and digestive system, along with altered release of some hormones.
Brain cells have opioid receptors and are sensitive to opiates like oxycodone. According to the 2008 text "Comparative Pharmacology for Anaesthetist," the binding of opiate medicines like oxycodone to brain cells slows their metabolic rate and internal activity. This slowing leads to a decrease in the signals sent out by the brain to various systems. Because the brain controls breathing, heart rate and alertness, decreased signaling related to slow metabolic activity can lead to drowsiness, poor concentration, slow breathing and decreased blood pressure.
Digestive System Metabolism
The digestive system is controlled by an intricate system of nerves that possess opioid receptors. According to a June 2009 article in "Regulatory Peptides," binding of opiate medicines like oxycodone to these receptors changes the metabolism within digestive system nerve cells, causing decreased overall activity of the stomach and intestines. This causes a delay in stomach emptying, which can lead to bloating and reduced appetite. There is also a decrease in the intestinal contractions that move food through the bowel, which often leads to opioid-induced constipation, or OIC.
The hypothalamus is the part of the brain containing cells that produce gonadotropin-releasing hormone, or GnRH, which stimulates the release of other hormones that ultimately affect the levels of sex hormones, such as estrogen and testosterone. A January 2009 "Journal of the American Osteopathic Association" article reports that opiate pain medicines like oxycodone decrease the release of GnRH, which leads to a decrease in sex hormone production. Sex hormone deficiencies can lead to metabolic effects on a variety of tissues, which might eventually cause decreased libido, infertility, depression, anemia and the weakening of bones.
Warning and Precautions
Opioids like oxycodone -- whether prescribed alone or in combination with other medications such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) -- carry the risk of dependence, addiction and overdose. It is not clear if oxycodone increases the risk of birth defects, but regular use during pregnancy can cause dependence in the developing baby and breathing problems in the newborn if taken by the mother near the time of birth. The drug also passes into a mother's breast milk and can cause breathing problems in a breastfed baby.
Taking oxycodone in amounts higher than prescribed can lead to life-threatening overdose. Signs and symptoms of overdose include:
-- Extreme drowsiness or loss of consciousness.
-- Slow heart rate and low blood pressure.
-- Slow, shallow breathing or periods of not breathing.
-- Limpness of the body.
Call 911 immediately if any of these signs or symptoms occur in someone taking oxycodone.