Fluoxetine

💊 What is Fluoxetine used for?

• •Major depressive disorder (depression), short-term and long-term treatment
• •Obsessive-compulsive disorder (OCD), with obsessions and compulsions
• •Bulimia nervosa, to reduce binge-eating and vomiting behaviors (the label says it is not approved for use in children for this use)
• •Panic disorder, with or without agoraphobia (the label says it is not approved for use in children for this use)
• •Depressive episodes linked to bipolar I disorder, when taken together with olanzapine (the label says fluoxetine alone is not indicated for this)
• •Treatment-resistant depression, when taken together with olanzapine (the label says fluoxetine alone is not indicated for this)

How it works

The label describes fluoxetine as a selective serotonin reuptake inhibitor (SSRI). The label excerpt provided does not explain the mechanism in more detail.

How it is usually taken

• •The label says adult starting doses are taken in the morning. Higher doses may be taken once a day in the morning or split into morning and noon doses. The dose may be increased after several weeks if improvement is not enough. Doses are usually lower or given less often for people with liver problems, older adults, people with other illnesses, or people taking several other medicines. The label notes that changes in dose take several weeks to be fully reflected in the blood. Follow the instructions from your prescriber or pharmacist.

Comes as

• •Capsules, 10 mg (white to off-white powder in a light blue and light orange capsule)
• •Capsules, 20 mg (white to off-white powder in a light blue and light green capsule)
• •Capsules, 40 mg (white to off-white powder in a light blue and white capsule)

⚠️ Fluoxetine side effects

🛑 Who should not take Fluoxetine, and who should be careful

The label says not to take it if

• 🚨You are allergic to fluoxetine hydrochloride or any of its ingredients. The label excerpt is cut off at this point, so the full list of ingredients is not shown here.
• 🚨You are taking an MAOI (monoamine oxidase inhibitor) intended to treat psychiatric disorders, or you took one within 5 weeks before stopping fluoxetine. The label says you should not take fluoxetine within 14 days of stopping an MAOI.
• 🚨You are being treated with linezolid or intravenous methylene blue. The label says fluoxetine should not be started in this case.
• 🚨You are taking pimozide. The label says it should not be used because of the risk of QT prolongation.
• 🚨You are taking thioridazine, or you took it within 5 weeks before stopping fluoxetine. The label says it should not be used because of the risk of QT prolongation and higher thioridazine levels.

Tell your doctor before taking it if

• •The label says to talk with your healthcare provider about the risks of treating depression and the risks of not treating it.
• •Tell your provider if you take a blood thinner such as warfarin, an NSAID, or aspirin, because the risk of bleeding may increase.
• •Tell your provider if you have a history of seizures or conditions that may lower the seizure threshold.
• •Tell your provider if you have a risk of bipolar disorder. The label says the provider should screen for bipolar disorder and watch for mania or hypomania.
• •Tell your provider if you have a heart rhythm problem or other risk factors for QT prolongation.
• •Tell your provider if you have a narrow-angle eye condition, because the label says angle-closure glaucoma has occurred with antidepressants in people with narrow angles.
• •The label says fluoxetine may impair judgment, thinking, and motor skills, so use caution when operating machinery.
• •The label says that people with liver problems, older adults, and people with other illnesses or several medicines may need lower or less frequent doses.

🔀 Fluoxetine with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •MAOIs: Do not use with fluoxetine or within the time periods listed in the label.
• •Drugs broken down by the CYP2D6 enzyme pathway: The label says fluoxetine is a potent inhibitor of this pathway.
• •Tricyclic antidepressants (TCAs): The label says levels may need monitoring when given with fluoxetine or soon after stopping it.
• •Other medicines that act on the central nervous system: Use caution. The label says lower starting doses of these drugs and careful monitoring may be considered.
• •Benzodiazepines: The label mentions diazepam and alprazolam as examples with noted effects.
• •Antipsychotics: The label says fluoxetine may raise haloperidol and clozapine levels.
• •Anticonvulsants: The label says fluoxetine may raise phenytoin and carbamazepine levels, which may cause anticonvulsant toxicity.
• •Other serotonergic drugs: Other SSRIs, SNRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, tryptophan, and St. John's Wort may increase the risk of serotonin syndrome.
• •Blood thinners and drugs that affect clotting, such as NSAIDs, aspirin, and warfarin: May increase the risk of bleeding.
• •Drugs that prolong the QT interval: Use with caution. Do not use with thioridazine or pimozide.
• •Olanzapine: When used together with fluoxetine, the label says to also read the drug interaction section of the Symbyax package insert.

Alcohol and food

The label does not say.

🤰 Fluoxetine in pregnancy and breastfeeding

Pregnancy

The label says there is a pregnancy exposure registry for people taking antidepressants during pregnancy. Healthcare providers are encouraged to register patients by calling 1-844-405-6185. The label says exposure to SSRIs, especially in the month before delivery, has been linked to less than a 2-fold increase in the risk of postpartum bleeding. Available studies have not shown an increased risk of major birth defects or miscarriage. Some studies reported heart-related birth defects, but the label says these studies do not prove cause. The label also notes risks from untreated depression in pregnancy, a newborn lung condition called persistent pulmonary hypertension of the newborn (PPHN), and poor newborn adaptation after SSRI exposure. Talk with your healthcare provider about these risks and benefits.

Breastfeeding

The label does not say.

🗓️ Storage, missed doses and taking too much

Storage

Store at 20 to 25 °C (68 to 77 °F). Short excursions to 15 to 30 °C (59 to 86 °F) are allowed, according to the label.

If a dose is missed

The label does not say.

If too much is taken

The label lists these effects from fluoxetine overdose: seizures, which may be delayed; altered mental status, including coma; heart problems, which may be delayed, such as abnormal heart rhythms and cardiac arrest; high blood pressure, which is the most common blood pressure change, though low blood pressure can occur rarely, including with alcohol; and serotonin syndrome, which may be more likely when other serotonin-raising drugs are involved. The label says activated charcoal may be considered for people who arrive early after an overdose. It also suggests contacting a Poison Center at 1-800-221-2222 or a medical toxicologist. If you think someone has overdosed, get emergency medical help right away.

🗒️ Questions to ask about Fluoxetine

• Is this medicine right for my condition, and how long will I need to take it?
• What signs should make me call you right away, especially changes in mood or suicidal thoughts?
• Which of my current medicines, including blood thinners, pain relievers, or supplements, could interact with fluoxetine?
• How long will it take before I notice a benefit, and what should I do if I do not feel better?
• What should I do if I miss a dose, and how should I plan to stop the medicine safely if needed?
• Should I have my heart rhythm, sodium levels, or weight checked during treatment?
• Can I drive or use machinery while taking this medicine?

❓ Fluoxetine: frequently asked questions