From the Guidelines
5mg of oxycodone is generally considered stronger than 50mg of tramadol. According to the most recent evidence from 1, the conversion factor for oxycodone is 1.5, while the conversion factor for tramadol is 0.2. This means that 5mg of oxycodone is equivalent to 7.5mg of morphine, while 50mg of tramadol is equivalent to 10mg of morphine. Therefore, 5mg of oxycodone is approximately equivalent to 75-100mg of tramadol in terms of pain relief, as supported by the conversion factors provided in the study 1.
The difference in potency between oxycodone and tramadol occurs because oxycodone has a higher binding affinity for mu-opioid receptors in the brain and spinal cord, which are primarily responsible for pain relief effects. Additionally, tramadol works through a dual mechanism - it has weak opioid activity and also inhibits the reuptake of serotonin and norepinephrine, whereas oxycodone acts primarily as a pure opioid agonist.
Some key points to consider when comparing these medications include:
- The type and severity of pain being treated
- Individual patient factors, such as medical history and current medications
- Potential side effects, including risks of dependence, respiratory depression, and other opioid-related side effects
- The importance of using the lowest effective dose to minimize risks, as emphasized in the study 1
It's also important to note that the study from 1 provides additional context on the use of tramadol, including its maximum daily dose and potential side effects. However, the most recent and highest-quality evidence from 1 provides the strongest support for the recommendation that 5mg of oxycodone is generally considered stronger than 50mg of tramadol.
From the Research
Comparison of Tramadol and Oxycodone
- The analgesic potency of tramadol is about 10% of that of morphine following parenteral administration 2.
- Oxycodone 5 mg/ibuprofen 400 mg provided significantly greater analgesia compared with oxycodone 5 mg/acetaminophen 325 mg, hydrocodone 7.5 mg/acetaminophen 500 mg, and placebo 3.
- A study comparing oxycodone and tramadol found that oxycodone is not less effective than tramadol in an emergency unit 4.
- Tramadol 100 mg was statistically superior to placebo for total pain relief score, sum of pain intensity difference scores, and time of remedication, whereas tramadol 50 mg was statistically superior to placebo only for remedication time 5.
Efficacy and Safety
- "Weak" opioid analgesics, including tramadol, are no less risky than morphine and can have the same dose-dependent adverse effects 6.
- The potency of tramadol is strongly influenced by the cytochrome P450 isoenzyme CYP2D6 genotype, which varies widely from one person to another 6.
- Tramadol can cause a serotonin syndrome, hypoglycaemia, hyponatraemia, and seizures, in addition to the usual opioid-related adverse effects 6.
Dosage Comparison
- A direct comparison between 50mg of tramadol and 5mg of oxycodone is not available in the provided studies.
- However, based on the available data, it can be inferred that 5mg of oxycodone may be more potent than 50mg of tramadol, considering the analgesic potency of tramadol is about 10% of that of morphine, and oxycodone is generally considered to be stronger than morphine 2, 3.