- Last Update On : 2013-03-02
Oxycodone is a pure agonist opioid whose principle therapeutic action is analgesia. Other members of the opioid agonists include morphine, hydromorphone, fentanyl, codeine and hydrocodone. In the U.S., several prescription drugs contain oxycodone in immediate-release formulation. Two common examples are Percocet and Percodan. OxyContin is a controlled-release formulation of oxycodone.
The usual adult oral dose of immediate release oxycodone is 2.5 to 5.0 mg every six hours. Patients with moderately severe pain may take 10 to 30 mg every four hours. The drug’s effects usually start in 10 to 30 minutes, peak in 60 to 90 minutes, and last for 4 to 6 hours. Controlled-release tablets are available in 10, 20, 40, 80 and 160 mg. In general, OxyContin tablets are taken every 12 hours. Steady state plasma levels are achieved within 24 to 36 hours. Plasma concentrations of oxycodone usually average about 30 ng/mL and are almost always less than 100 ng/mL. Plasma concentrations tend to be 25% higher in females than in males even after adjustment for body weight.
After absorption, oxycodone is widely distributed to skeletal muscle, liver, intestinal tract, lungs, spleen and brain. It is also excreted in breast milk. Oxycodone is extensively metabolized in the liver to noroxycodone and oxymorphone followed by glucuronidation. These metabolites have weaker analgesic effects and are primarily excreted by the kidney into the urine.
OxyContin has a very high potential for abuse because:
- It is highly potent
- Produces euphoria in addition to analgesia
- Is highly effective when taken orally
- Is readily available as a prescription drug.
Although OxyContin is intended to be swallowed whole, abusers often chew or crush tablets to get a rapid release of the drug. Crushed tablets can also be sniffed, snorted, smoked or taken rectally or transdermally. They can be dissolved in water and injected intramuscularly or intravenously. Intravenous administration gives abusers immediate effects within 5 minutes, while rectal administration takes 30 to 60 minutes.
The Drug Abuse Warning Nework (DAWN) report states that oxycodone abuse was 108% higher in 2000 than in 1998. It also reports that oxycodone was mentioned in 2% of all emergency department episodes in 2000. Oxycontin is increasingly being used by young adults along with MDMA/ectasy and Gamma Hyroxybutyrate (GHB) as a club drug.
Oxycodone overdose produces a constellation of signs that are referred to as the opioid toxindrome including:
- Mental depression
- Reduced bowel movement
- Cold and clammy skin
- Skeletal muscle flaccidity
The most severe consequence of an oxycodone overdose is central nervous system and respiratory depression, leading to stupor and coma. Administration of the opioid antagonist, naloxone, will generally reverse the toxic effects.
Most immunoassays are designed to detect opioids such as heroin, codeine and morphine, but typically do not detect hydrocodone and oxycodone. The Triage Drug Screen which is used for stat drugs of abuse testing is not very sensitive in detecting oxycodone. Another rapid test specifically for oxycodone, that can detect as little as 100 ng/mL, is available. Results are reported as positive or negative. CPT code is 80101. Specimen requirement is 2 mL of urine.