How does oxycodone work?

Oxycodone works by binding to mu, kappa and delta receptors in the central nervous system. More on how oxycodone works and how it affects the brain here.

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Experts do not know exactly how oxycodone works.

But, in general, oxycodone alters your perception and emotional response to pain by binding to opioid receptors in the central nervous system (this is how people get high on oxy).   More here on how quickly and how long oxycodone works, plus how you can possibly optimize oxycodone to make it work better. We invite you to ask your questions about oxycodone at the end.

How does oxycodone affect the brain and nervous system?

Although experts do not know exactly HOW oxycodone works, they do know that pain relief occurs through chemical processes in the central nervous system. And although the precise mechanism of analgesic action is unknown, opioid-induced pain relief occurs without loss of consciousness and is very useful as a pain management therapy. So what’s important to know about oxycodone and your brain? And what adverse side effects can occur in the nervous system as a result of taking oxycodone?

Oxycodone affects the brain and nervous system by acting in the same way as other opioids. Oxycodone binds to mu, kappa and delta receptors in the central nervous system, inhibits adenylyl-cyclase and hyperpolarisation of neurons, and decreases excitability. Opiate agonists like oxycodone do not alter the threshold or responsiveness of nerve endings to stimuli nor the conduction of impulses along peripheral nerve. Instead, oxycodone alter the perception of pain at the spinal cord and higher levels in the central nervous system (substantia gelatinosa, spinal trigeminal nucleus, periaqueductal gray, periventricular gray, medullary raphe nuclei, hypothalamus) as well as your emotional response to pain. The most common results are pain relief and euphoria, the main reason behind oxycodone addictive effect.

However, oxycodone also affects other parts of the brain and nervous system. In addition to pain relief, oxycodone stops the cough reflex, slows breathing and causes the pupils to dilate. Opioids like oxycodone also have the ability to lower body temperature and to suppress opiate withdrawal. The two other significant effects of oxycodone on the nervous system are:

Respiratory depression – Oxycodone also produces respiratory depression (slowed breathing) by direct action on brain stem respiratory centers. Slowed breathing involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and to electrical stimulation and can cause death in cases of oxycodone overdose.

Suppressed cough – oxycodone is an antitussive, or cough suppressant. Oxycodone depresses the cough reflex by direct effect on the cough center in the medulla.

How does oxycodone work in the body?

Oxycodone is a powerful pain reliever, that works in the body by affecting the central nervous system (see below). Most people use oxycodone for pain relief, although it is also prescribed (less frequently) as a cough suppressant. Side effects for taking oxycodone are those common to opioids and include mainly:

  1. constipation
  2. drowsiness
  3. nausea

Vomiting, itchy skin and dizziness are less common. The intensity of these side effects tends to decrease over the course of time as tolerance to oxycodone builds.

How fast or quickly does oxycodone work?

How fast oxycodone works depends upon what version of oxycodone you take and how you take it.   For example, if you are take oxycodone orally as prescribed, controlled release versions of oxycodone start to work a little more slowly than immediate release versions.  If, however, you chew, crush, snort or inject either version of oxycodone, effect is near immediate. These modes of administration significantly increase the risk of oxycodone addiction, adverse side effects and overdose and are never medically recommended.  Still, keep in mind that how much oxycodone can you take at once depends upon your exposure to opiates.

Controlled release oxycodone onset of effects – Oxycodone CR effects usually begin one hour after oral administration.

Immediate release oxycodone onset of effects – Analgesic effect occurs within 10-15 minutes for immediate release oxycodone (following oral administration of conventional preparations of oxycodone).

How long does oxycodone work?

Controlled release oxycodone duration of action  – Extended-release tablets of oxycodone are formulated to provide controlled delivery of oxycodone and oxycodone CR effects last for about 12 hours. This is why doctors usually prescribe oxycodone extended release tablets only twice daily.

Immediate release  oxycodone duration of action – Immediate release oxycodone reaches its maximum therapeutic levels in 30-60 minutes, and persists for 3-6 hours. This is why doctor usually prescribe immediate release oxycodone every 4-6 hours, as needed.

Can oxycodone work better?

Yes, it’s possible to get more pain relief for longer while taking oxycodone.  But keep in mind that the minimum effective plasma concentration of oxycodone to achieve analgesia varies widely. Plus, the minimum effective concentration of oxycodone for any person may increase with repeated dosing due to an increase in pain and/or development of tolerance. So, to make oxycodone work better, be sure first that your doctor has prescribed you with appropriate oxycodone doses that account for your pain threshold and tolerance to opioids.

Second, if you are taking immediate release oxycodone, you can eat a high fat meal at the same time that you take oxycodone. Both oxycodone bioavailability and peak plasma oxycodone concentration are significantly altered by consumption of a high-fat meal. In other words, your body absorbs more oxycodone and will feel the effects of oxycodone longer when you take immediate release oxycodone with high fat.

Finally, special populations need to take care when considering oxycodone for therapeutic use. Children and those with liver/renal failure have a unique oxycodone pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.

Does oxycodone work for everyone?

No. Opioid pain killers like oxycodone are not for everyone. Although analgesic effect can occur, some adverse side effects may not be manageable. And there is always the risk of developing dependence on oxycodone, or addiction to oxycodone.

If you still have questions about how oxycodone works or how to use oxycodone, please leave them here. We do your best to answer all legitimate questions with a personal and prompt reply.

Reference Sources: Daily Med: Oxycodone hydrochloride
Daily Med: Oxycodone hydrochloride controlled release
TOXNET: Oxycodone
PubMed: Oxycodone: a pharmacological and clinical review
PubMed: The pharmacokinetics of oxycodone
PubMed: Differential effects of food on the bioavailability of controlled-release oxycodone tablets and immediate-release oxycodone solution
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.
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