codeine vs morphine
Side-by-side comparison of codeine and morphine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
CYP2D6 Inhibitors Codeine is metabolized by CYP2D6 to form morphine. The concomitant use of acetaminophen and codeine phosphate tablets and CYP2D6 inhibitors (e.g., paroxetine, fluoxetine, bupropion, quinidine) can increase the plasma concentration of codeine, but can decrease the plasma concentration of active metabolite morphine, which could result in reduced analgesic efficacy or symptoms of opioid withdrawal, particularly when an inhibitor is added after a stable dose of acetaminophen and codeine phosphate tablets is achieved (see CLINICAL PHARMACOLOGY ). After stopping a CYP2D6 inhibit...
Recommendation: Avoid taking these two medications together unless specifically directed by your doctor. Your healthcare provider will need to monitor you very closely for signs of an overdose.
This medicine contains acetaminophen and codeine. It is used to treat mild to moderate pain when other pain medicines are not strong enough.
Morphine is a strong pain medicine. It is used to treat severe pain that needs an opioid medicine when other treatments don't work well enough.
This medicine is used to manage mild to moderate pain. It is for when an opioid medicine is appropriate. You should only use it if other pain treatments are not working well enough for you.
Morphine is used to manage severe pain in adults and children who weigh at least 110 pounds. It is for pain that requires an opioid medicine. It is used when other pain treatments are not strong enough or cannot be tolerated.
Codeine works in the brain to change how your body feels and responds to pain. Acetaminophen also helps to relieve pain. Together, they provide pain relief.
Morphine works by attaching to receptors in the brain and spinal cord. These receptors are involved in sending pain signals. By binding to these receptors, morphine blocks pain signals and reduces pain.
- • Feeling drowsy
- • Lightheadedness
- • Dizziness
- • Feeling sleepy
- • Shortness of breath
- • Constipation
- • Nausea
- • Feeling sleepy
- • Lightheadedness
- • Dizziness
- Allergic reaction to the medicine 806
- Feeling sick to your stomach 487
- Feeling unwell 374
- Medicine not working 370
- Throwing up 364
- Pain 5,857
- Feeling sick to your stomach 5,534
- Medicine not working 5,006
- Throwing up 4,333
- Death 4,305
This medicine can be habit-forming, leading to addiction, abuse, and misuse, which can result in overdose and death. Serious, life-threatening breathing problems can occur, especially when starting the medicine or after a dose increase. Accidental ingestion, especially by children, can cause a fatal overdose. Do not give this medicine to children under 12 years old, or to children under 18 after tonsil or adenoid removal, due to the risk of life-threatening breathing problems. This medicine can also harm your liver. Taking this medicine with certain other medicines like benzodiazepines or other CNS depressants can cause serious side effects, including death.
Morphine can cause addiction, abuse, and misuse, which can lead to overdose and death. It can also cause life-threatening breathing problems, especially when you start taking it or after a dose increase. Accidental ingestion, especially by children, can cause a fatal overdose. Taking morphine with benzodiazepines or other CNS depressants (including alcohol) can cause severe sedation, breathing problems, coma, and death. If you use morphine for a long time during pregnancy, your baby could have withdrawal symptoms after birth.
This medicine can cause withdrawal symptoms in newborns if taken during pregnancy. Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if this medicine passes into breast milk.
Morphine may harm your unborn baby. Using morphine for a long time during pregnancy can cause withdrawal symptoms in the newborn. Tell your doctor if you are pregnant or plan to become pregnant.
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How to Read This codeine vs morphine Comparison
codeine is classified in the Opioid Analgesic drug class, while morphine sits within the Opioid Analgesic class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, codeine has 2,401 submissions while morphine has 25,035. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to codeine is turned into morphine by your body to help with pain. taking both medications at the same time can lead to too much morphine in your system, which increases the risk of dangerous side effects.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between codeine and morphine — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.