What it is used for
- Depression
- Obsessive-compulsive disorder (OCD)
- Bulimia nervosa
- Panic disorder
- Premenstrual dysphoric disorder
How it works
Fluoxetine raises the level of serotonin, a mood-related chemical messenger, in the brain by reducing its reuptake into nerve cells. This is thought to gradually lift mood and reduce anxiety and obsessive symptoms.
How it is taken
Usually available as capsules, tablets and an oral liquid, including some longer-acting forms. It is taken by mouth and has a long-lasting effect in the body. Take it exactly as your doctor or pharmacist directs and follow the label; do not adjust or stop it without medical advice.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Nausea
- Headache
- Trouble sleeping
- Feeling nervous, restless or anxious early on
- Tiredness or drowsiness
- Reduced appetite
- Diarrhoea
- Dry mouth
- Sexual difficulties
- Sweating
Serious effects — get help
- New or worsening suicidal thoughts, especially early in treatment (seek urgent help)
- Serotonin syndrome: agitation, fever, fast heartbeat, muscle twitching, confusion
- Severe allergic reaction (rash, facial or throat swelling, trouble breathing)
- Unusual bleeding or bruising
- Seizures
- Signs of low sodium: confusion, weakness, unsteadiness
- Switch into mania (racing thoughts, very high energy) in people prone to it
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- MAOI antidepressants (must not be combined, including a gap before and after)
- Other serotonin-raising medicines (triptans, tramadol, St John's Wort, other antidepressants)
- Blood thinners, aspirin and NSAIDs (bleeding risk)
- Some heart-rhythm medicines (QT prolongation)
- Medicines processed by the liver, as fluoxetine can affect their levels
- Alcohol
Who should take care
- Tell your clinician if you are pregnant, planning pregnancy or breastfeeding
- Use with caution with liver problems, epilepsy, bipolar disorder, diabetes or bleeding disorders
- Because it stays in the body a long time, effects and interactions can persist after stopping
- Closer monitoring may be needed for people under 25
- Do not start or stop without medical advice