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Oxycodone: 6 things you should know

Medically reviewed by C. Fookes, BPharm Last updated on Aug 16, 2018.

1. How it works

  • Oxycodone is a morphine-like, strong pain-relieving medicine used for the relief of severe pain that is unresponsive to less potent pain-relieving medicines (analgesics).
  • Oxycodone is relatively selective for the mu opioid receptor, although it may bind to other opioid receptors at higher dosages. Oxycodone is a full agonist at the mu receptor (full agonists have a larger effect at higher dosages).
  • Oxycodone belongs to the group of drugs known as opioids or opioid analgesics. Oxycodone may also be called a narcotic analgesic.

2. Upsides

  • Effective against moderate-to-severe pain, including cancer-related pain.
  • Longer-lasting (extended-release) tablets are available (brand name OxyContin).
  • Oxycodone is also available in combination with acetaminophen, ibuprofen, or aspirin for added pain control.
  • Oxycodone is less likely to cause an itchy rash compared to other opioids such as morphine.
  • Oxycodone does not have a ceiling effect for analgesia, which means that if a person finds that oxycodone is no longer controlling their pain, a higher dosage should provide pain relief. However, the risk of side effects, such as respiratory and CNS depression, increase with higher dosages of oxycodone.
  • Generic oxycodone is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Sedation which may impair your reaction skills and affect your ability to drive or operate machinery. Avoid alcohol as the combination can lead to dangerous or fatal side effects.
  • Other common side effects include constipation, dizziness, nausea, vomiting, and confusion. Can lead to low blood pressure, which may increase the risk of falls. May cause flushing, red eyes, sweating, and an itchy rash (although less likely to cause an itchy rash than some other opioids).
  • Oxycodone should be reserved for more severe types of pain, such as that caused by cancer. Oxycodone can be habit-forming (addictive), even at regular doses. It has a high abuse potential, and personal legitimate supplies of oxycodone may be sought out by drug seekers.
  • Respiratory depression (slow and shallow breathing), which may be fatal or life-threatening can occur with oxycodone use. The risk is greatest during the first 24 to 72 hours after drug initiation or after a dosage increase. Children, the elderly, the frail, or those with pre-existing respiratory disease are more at risk.
  • The dosage of oxycodone may need reducing in people with kidney or liver disease.
  • Oxycodone interacts with a number of different drugs, including those that inhibit or induce hepatic enzymes, particularly CYP3A4 or CYP2D6 (such as erythromycin, ketoconazole, ritonavir); depress the CNS (such as benzodiazepines, muscle relaxants, antipsychotics); have partial agonist or mixed effects on opioid receptors (such as buprenorphine, pentazocine); diuretics; with anticholinergic effects; and monoamine oxidase inhibitors.
  • Interaction or overdosage may also cause serotonin syndrome. Symptoms include mental status changes such as agitation, hallucinations, coma, delirium, fast heart rate, dizziness, flushing, muscle tremor or rigidity and stomach symptoms (including nausea, vomiting, and diarrhea).
  • Abrupt discontinuation of oxycodone in a person who has become physically dependent on it may lead to a withdrawal syndrome and symptoms such as restlessness, pupil dilation, watery eyes and a runny nose, sweating, muscle aches, insomnia, irritability and gastrointestinal complaints. Babies born to mothers who are physically dependent on oxycodone will also be physically dependent.
  • Not for use in patients with severe asthma or other breathing problems, or a blockage in the stomach or intestines.
  • Long-term use of oxycodone also affects the endocrine system, which may cause symptoms such as sexual dysfunction, an absence of periods, or infertility.

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

4. Bottom Line

Oxycodone is a potent pain-relieving medicine which should be reserved for mainly cancer-related pain. It carries a high potential for addiction and common side effects include sedation and constipation.

5. Tips

  • Oxycodone may be taken with or without food.
  • Take oxycodone exactly as directed by your doctor. Do not take more than prescribed unless advised to do so by your doctor. The effective dosage for pain relief varies significantly from person to person. Over time, your dosage may need adjusting, especially if you find that your pain is no longer being controlled. Talk with your doctor if this happens.
  • If you take oxycodone extended-release tablets, swallow them whole. Do not chew, break, divide, crush, or dissolve the tablets.
  • Avoid alcohol while taking this medicine; fatal breathing problems may occur.
  • Oxycodone may cause sedation which may impair your reaction skills and affect your ability to drive or operate machinery. Do not drive or operate machinery if oxycodone impairs you in this way.
  • Withdrawal symptoms (muscle and bone pain, diarrhea, insomnia, vomiting) may occur if long-term oxycodone is stopped abruptly. Your doctor will advise you how to discontinue oxycodone slowly if you need to stop taking it.
  • Do not use during pregnancy and breastfeeding unless specifically recommended by your doctor.
  • Oxycodone may cause constipation which can be relieved with laxatives. Nausea or vomiting caused by oxycodone may be treated with antiemetics. Talk to your doctor if you experience any troublesome side effects.
  • May lower blood pressure on standing. Take your time when going from a lying down to a standing up position.
  • Avoid grapefruit juice, grapefruit products, Seville oranges (used to make orange marmalade) and tangelos (a tangerine-grapefruit cross) due to possible food-drug interactions.
  • Keep this medicine in a safe place and out of the reach of children and pets. Accidental ingestion of even one dose of OxyContin (extended-release oxycodone), especially by children, can result in a fatal overdose of oxycodone.

6. Response and Effectiveness

  • For immediate-release formulations of oxycodone, peak concentrations are reached within 1-2 hours and the duration of effect is approximately 3-4 hours.
  • Extended-release formulations of oxycodone (Oxycontin) last for 12 hours. Longer-acting formulations of oxycodone should not be initiated without a trial of shorter-acting formulations first.
  • Side effects (such as nausea, vomiting, respiratory depression) are more likely with higher dosages of oxycodone; however, long-term users of oxycodone may develop a tolerance to these effects.


Oxycodone tablets [Package Insert]. Revised 08/2017. CorePharma LLC Nieminen TH, Hagelberg NM, Saari TI, et al. Grapefruit juice enhances the exposure to oral oxycodone. Basic Clin Pharmacol Toxicol. 2010 Oct;107(4):782-8. doi: 10.1111/j.1742-7843.2010.00582.x.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use oxycodone only for the indication prescribed.

Copyright 1996-2019 Revision date: August 16, 2018.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.