From the Guidelines
Codeine and oxycodone are both opioid pain medications, but they differ significantly in potency, uses, and side effect profiles, with oxycodone being approximately 1.5 times more potent than codeine, making it more effective for moderate to severe pain. The key differences between codeine and oxycodone lie in their potency, metabolism, and usage. Codeine is often combined with acetaminophen or other non-opioid analgesics in over-the-counter or prescription formulations, whereas oxycodone is available only by prescription 1. Metabolism is another key difference - codeine must be converted to morphine in the liver to be effective, and about 10% of people lack the enzyme (CYP2D6) needed for this conversion, making codeine ineffective for them. Oxycodone works directly without requiring this conversion.
Key Differences
- Potency: Oxycodone is more potent than codeine
- Metabolism: Codeine requires conversion to morphine, while oxycodone does not
- Usage: Codeine is often used for mild to moderate pain, while oxycodone is used for moderate to severe pain
- Side effects: Both can cause constipation, nausea, drowsiness, and respiratory depression, but these effects are typically more pronounced with oxycodone due to its greater potency
Dosage and Administration
- Typical codeine doses range from 15-60mg every 4-6 hours
- Oxycodone is usually prescribed at 5-15mg every 4-6 hours for immediate-release formulations 1
Recent Guidelines
Recent guidelines suggest that oxycodone and morphine have similar analgesic and adverse effects, making them interchangeable in the front-line treatment setting for cancer-related pain 1. However, it's essential to consider the individual patient's needs and medical history when choosing between codeine and oxycodone. Ultimately, the choice between codeine and oxycodone should be based on the patient's specific condition, medical history, and the potential risks and benefits of each medication.
From the Research
Difference between Codeine and Oxycodone
- Codeine and oxycodone are both opioid analgesics used to treat pain, but they have different properties and uses 2, 3, 4, 5, 6.
- Codeine is a naturally occurring opioid, while oxycodone is a semisynthetic derivative of thebaine, an opioid alkaloid 2.
- Oxycodone has been shown to have a higher abuse potential than codeine, with studies suggesting it can lead to transitioning to other opioids 2, 5.
- In terms of analgesic efficacy, oxycodone has been found to be more effective than codeine in some studies, particularly in the treatment of acute pain 3, 4.
- However, codeine and oxycodone can both cause similar adverse effects, including nausea, vomiting, and respiratory depression, especially in high doses or in individuals with certain genetic predispositions 3, 5, 6.
- The potency of codeine is influenced by the cytochrome P450 isoenzyme CYP2D6 genotype, which can vary widely from person to person, leading to reports of overdosing or underdosing 6.
- Oxycodone, on the other hand, has a more predictable pharmacokinetic profile, but its use can still lead to dependence and overdose, particularly when combined with other substances 2, 5.