codeine vs fentanyl
Side-by-side comparison of codeine and fentanyl Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
This medicine contains acetaminophen and codeine. It is used to treat mild to moderate pain when other pain medicines are not strong enough.
Fentanyl Citrate Injection is a strong opioid pain medicine. It is used to provide short-term pain relief, often during and after surgery.
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.
Fentanyl Citrate Injection is used to manage pain during and after surgery. It can be used alone or with other medicines during general or regional anesthesia. It may also be used with oxygen for high-risk patients during certain surgeries.
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.
Fentanyl is an opioid that works by binding to receptors in the brain and spinal cord. This binding decreases the feeling of pain. It can also cause sleepiness and slow breathing.
- • Feeling drowsy
- • Lightheadedness
- • Dizziness
- • Feeling sleepy
- • Shortness of breath
- • Nausea
- • Vomiting
- • Dizziness
- • Blurred vision
- Allergic reaction to the medicine 806
- Feeling sick to your stomach 487
- Feeling unwell 374
- Medicine not working 370
- Throwing up 364
- Misuse of drugs 10,453
- Pain 7,248
- Drug addiction 6,027
- Harmful effect from drugs 5,847
- Taking too much of a drug 5,722
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.
Fentanyl Citrate Injection can cause serious and life-threatening risks: * Addiction, abuse, and misuse can lead to overdose and death. Your doctor will assess your risk before prescribing and monitor you regularly. * Life-threatening respiratory depression (slowed or stopped breathing) can occur, especially when starting the medicine or after a dose increase. Proper dosing is essential. * Taking fentanyl with benzodiazepines (like Valium or Xanax) or other CNS depressants (including alcohol) can cause severe sleepiness, slowed breathing, coma, and death. This combination should be avoided unless there are no other options. * Using fentanyl with certain other medicines (CYP3A4 inhibitors or inducers) can change the amount of fentanyl in your blood, leading to dangerous side effects or withdrawal symptoms. Your doctor will monitor you closely if these medicines are used together.
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.
Using fentanyl for a long time during pregnancy can cause withdrawal symptoms in the newborn. Fentanyl is not recommended during labor or delivery because it can cause breathing problems in the baby.
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How to Read This codeine vs fentanyl Comparison
codeine is classified in the Opioid Analgesic drug class, while fentanyl 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 fentanyl has 35,297. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. 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 fentanyl — 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.