Oxycodone vs. Morphine: Is One More Addictive?

Oxycodone and morphine latch to the same receptors and cause similar effects. However, oxycodone is much stronger. 

Researchers say oxycodone also has a high “likeability” by users, making it a more addictive option.[11] While all opioids can be dangerous, oxycodone is most closely associated with addiction.[12]

Understanding Oxycodone & Morphine 

Oxycodone and morphine are opioid analgesics. This term refers to medications that provide pain relief by latching to opioid receptors within the brain and body. Any substance that tackles this task is an opioid analgesic.[13] However, oxycodone and morphine are very different.

What Is Morphine?

Morphine is a non-synthetic narcotic pain reliever derived from opium. It reduces physical pain, inhibits appetite, and can be used to treat severe cough.

Morphine is prescribed as an intravenous injection, oral solution, and immediate-release and extended-release tablets and capsules. Like oxycodone, morphine produces a pleasurable high that people can quickly become addicted to.[2]

Morphine is metabolized by the enzyme UGT2B7, and up to 48% of it becomes available for pain relief when it’s used.[14] This low bioavailability score means that the drug is considered weaker than oxycodone, and it might explain why this drug isn’t as frequently abused as oxycodone is.

What Is Oxycodone?

Oxycodone is a semisynthetic narcotic pain reliever that is synthesized from the poppy plant. It is legally prescribed for the treatment of moderate to severe pain, such as following an injury or surgery, or to cancer patients.

Oxycodone is available in immediate-release and extended-release forms, depending on the needs of the patient. It produces effects similar to morphine.[1] However, oxycodone is stronger.

Oxycodone is metabolized in the liver, and up to 80% of each dose becomes available for pain relief when it’s used.[14] Since so much of each dose becomes bioavailable, it’s considered a stronger drug. Researchers say oxycodone is 1.5 times more potent than morphine.[15]

How Do Morphine & Oxycodone Work?

Morphine and oxycodone work by interfering with opioid receptors throughout the body. They bind to receptors in the brain, spinal cord, and other organs to block the perception of pain. The medications can be swallowed, injected, or snorted in cases of misuse.[3] 

In addition to reducing pain, opioids can cause people to feel relaxed, happy, and sometimes euphoric. Such positive feelings reinforce opioid use and dangerous drug use habits. 

Once addicted, medications and behavioral therapies are likely needed to treat opioid use disorder (OUD).[3] If someone attempts to stop the use of morphine or oxycodone suddenly after addiction has taken hold, they will experience uncomfortable withdrawal symptoms. Relapse is very likely during this time.

Comparing Oxycodone & Morphine

Oxycodone and morphine are two of the most prescribed prescription opioids. Knowing how they compare can better inform their safe use. Use the table below to better understand how oxycodone and morphine are similar and different.[4-9] 

Is One Medication More Addictive or More Effective?

The effectiveness of oxycodone or morphine depends on the individual’s level of pain, needs, and personal response to the medication. However, a 2018 study found that both oxycodone and morphine are equally effective in managing pain. A meta-analysis of studies of cancer patients with moderate to severe pain found that both oxycodone and morphine effectively reduced pain without significant negative side effects.[6]

Doctors are encouraged to use the lowest effective opioid dose when treating patients.[13] Since morphine is the weaker of the two medications, it might be appropriate for people dealing with mild or moderate pain caused by a pulled muscle or dental procedure.

Researchers say oxycodone is a more effective solution for some types of pain, including intense discomfort.[16] When morphine isn’t enough, doctors might suggest oxycodone instead. People dealing with cancer-related pain, or those recovering from surgeries or broken bones, might need more relief than morphine can provide.

Using oxycodone can be dangerous, and doctors may not suggest it first to keep addiction risks low. Due to its potency and potential for euphoric side effects, oxycodone is a popular drug of misuse. People who are addicted to oxycodone may swallow the tablets or crush them up. They may then either snort the powder or dissolve it in water and inject the solution.[1]

Common Side Effects of Oxycodone & Morphine

As prescription opioids, oxycodone and morphine share similar side effects. The intensity of the side effects depends on the amount of the drug consumed and the individual’s response to the drug. 

Common side effects of oxycodone and morphine include the following:[3]

• Drowsiness
• Confused mental state
• Nausea and vomiting 
• Constipation
• Euphoria 
• Slowed breathing 

It is important to monitor the side effects of opioids closely, as they can lead to overdose. As central nervous system depressants, oxycodone and morphine can depress breathing and heart rate severely. Overdose on either drug could be fatal. 

Who Shouldn’t Take These Drugs?

Older people taking opioids are advised to do so with extreme caution. Older adults are more likely to suffer from various health conditions and take multiple medications, which can lead to dangerous medication interactions within the body and accidental misuse.

Likewise, pregnant women are advised against taking opioids, as they can lead to miscarriage, low birth weight, and neonatal abstinence syndrome. Babies born with opioids in their system may suffer withdrawal symptoms, which can be life-threatening, and require medication when born.[3]

People taking opioids are warned against the dangers of consuming alcohol at the same time. Alcohol is also a central nervous system depressant and increases the likelihood of overdose when consumed with opioids. Together, the substances can suppress breathing and heart rate to dangerously low levels. 

The Risk of Abuse With Oxycodone & Morphine

Although oxycodone is more commonly abused, addiction can develop to both types of opioids. Both drugs should only be taken exactly as prescribed and under a doctor’s supervision. 

If you’ve been misusing either drug, it’s not easy to stop on your own. Fortunately, many evidenced-based treatment methods are available, including the use of medication-assisted treatment (MAT), which combines the use of medications like buprenorphine and behavioral therapies.[10] Recovery from any opioid use disorder is possible with the right help.