citalopram vs fluoxetine
Side-by-side comparison of citalopram and fluoxetine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
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Citalopram is a medicine used to treat depression in adults. It belongs to a class of drugs called selective serotonin reuptake inhibitors (SSRIs).
Fluoxetine is a medicine that can help treat depression and other mental health conditions. It belongs to a class of drugs called selective serotonin reuptake inhibitors (SSRIs).
Citalopram is used to treat major depressive disorder (MDD) in adults. Depression can cause feelings of sadness, loss of interest, and difficulty functioning in daily life. This medicine can help improve your mood and overall well-being.
Fluoxetine can treat major depressive disorder in adults and children. It also treats obsessive-compulsive disorder (OCD) in adults and children. Fluoxetine can help with bulimia nervosa (an eating disorder) and panic disorder. Sometimes, it is used with another medicine called olanzapine to treat depression related to bipolar disorder.
Citalopram works by increasing the amount of serotonin in the brain. Serotonin is a chemical messenger that helps regulate mood. By blocking the reabsorption of serotonin, citalopram helps to improve communication between nerve cells and stabilize mood.
Fluoxetine works by increasing the amount of serotonin in your brain. Serotonin is a chemical that helps regulate mood. By increasing serotonin, fluoxetine can help improve mood and reduce symptoms of depression, OCD, and other conditions.
- • Ejaculation disorder (mostly delayed ejaculation)
- • Abnormal dreams
- • Problems ejaculating
- • Loss of appetite
- • Feeling anxious
- • Feeling weak
- Tiredness 8,930
- Feeling sick to your stomach 8,204
- Medicine not working 7,287
- Head pain 6,654
- Loose stools 6,214
- The medicine is not working 3,637
- The medicine is interacting with another medicine 3,336
- Harmful effect from different substances 3,316
- Feeling sick to your stomach 3,233
- Feeling tired 3,155
Antidepressants may increase the risk of suicidal thoughts and behaviors in young adults. Your doctor will monitor you closely for worsening depression or suicidal thoughts. Citalopram is not approved for use in children.
Antidepressants may increase the risk of suicidal thoughts and behaviors in children, teenagers, and young adults. Watch closely for worsening depression or suicidal thoughts. Tell your doctor right away if you notice any changes in mood or behavior. Fluoxetine is not approved for use in children younger than 7 years old.
Taking citalopram late in pregnancy may cause problems for the newborn. Talk to your doctor about the risks and benefits of taking this medicine while pregnant. There is a pregnancy registry to monitor outcomes, call 1-844-405-6185 to register.
Talk to your doctor if you are pregnant or plan to become pregnant. Fluoxetine should only be used during pregnancy if the benefit outweighs the risk to the baby. Breastfeeding is not recommended while taking fluoxetine.
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How to Read This citalopram vs fluoxetine Comparison
citalopram is classified in the Selective Serotonin Reuptake Inhibitor (SSRI) drug class, while fluoxetine sits within the Selective Serotonin Reuptake Inhibitor (SSRI) 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, citalopram has 37,289 submissions while fluoxetine has 16,677. 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 citalopram and fluoxetine — 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.