Fluoxetine

generic for Prozac

Fluoxetine Side Effects

See also Warning section.

Nausea, drowsiness, dizziness, anxiety, trouble sleeping, loss of appetite, tiredness, sweating, or yawning may occur. If any of these effects persist or worsen, tell your doctor promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: unusual or severe mental/mood changes (such as agitation, unusual high energy/excitement, thoughts of suicide), easy bruising/bleeding, muscle weakness/spasm, shakiness (tremor), decreased interest in sex, changes in sexual ability, unusual weight loss.

Get medical help right away if you have any very serious side effects, including: bloody/black/tarry stools, vomit that looks like coffee grounds, seizures, signs of kidney problems (such as change in the amount of urine), eye pain/swelling/redness, widened pupils, vision changes (such as seeing rainbows around lights at night, blurred vision).

If you have diabetes, fluoxetine may affect your blood sugar levels. Monitor your blood sugar regularly and share the results with your doctor. Your doctor may need to adjust your medication, diet, and exercise when you start or stop fluoxetine.

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.

Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
  • hypoglycemic disorder
  • hyperprolactinemia
  • hyponatremia
  • acquired hemolytic anemia
  • pancytopenia
  • aplastic anemia
  • increased risk of bleeding
  • purpura
  • thrombocytopenic disorder
  • acute confusion
  • manic disorder
  • hypomania
  • mood changes
  • depersonalization
  • suicidal ideation
  • abnormal sexual function
  • libido changes
  • disorder of ejaculation
  • bruxism
  • agitation
  • hyperkinesis
  • neuroleptic malignant syndrome
  • serotonin syndrome
  • cataracts
  • visual changes
  • optic neuritis
  • mydriasis
  • tinnitus
  • pulmonary thromboembolism
  • pulmonary hypertension
  • torsades de pointes
  • atrial fibrillation
  • prolonged QT interval
  • cardiac arrhythmia
  • cerebrovascular accident
  • thrombotic thrombocytopenic purpura
  • hypotension
  • ecchymosis
  • vasodilation of blood vessels
  • pharyngitis
  • sinusitis
  • laryngeal edema
  • laryngismus
  • eosinophilic pneumonia
  • bronchospastic pulmonary disease
  • xerostomia
  • gastrointestinal ulcer
  • dyspepsia
  • constipation
  • hepatic failure
  • drug-induced hepatitis
  • obstructive hyperbilirubinemia
  • gastrointestinal hemorrhage
  • renal failure
  • erectile dysfunction
  • gynecomastia
  • galactorrhea not associated with childbirth
  • abnormal vaginal bleeding
  • abnormal uterine bleeding
  • skin photosensitivity
  • allergic dermatitis
  • erythema multiforme
  • Stevens-Johnson syndrome
  • erythema nodosum
  • exfoliative dermatitis
  • pruritus of skin
  • alopecia
  • urticaria
  • arthralgia
  • drowsy
  • memory impairment
  • seizure disorder
  • dizziness
  • insomnia
  • fever
  • flu-like symptoms
  • hyperhidrosis
  • chills
  • tremor
  • dysgeusia
  • ataxia
  • dyskinesia
  • skin rash
  • petechiae
  • anorexia
  • weight loss
  • polydipsia
  • headache disorder
  • palpitations
  • lymphadenopathy
  • dyspnea
  • yawning
  • cough
  • chest pain
  • nausea
  • vomiting
  • flatulence
  • diarrhea
  • dysuria
  • increased urinary frequency

Drug Interactions

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Fluoxetine can stay in your body for many weeks after your last dose and may interact with many other medications. Before using any medication, tell your doctor or pharmacist if you have taken fluoxetine in the previous 5 weeks.

Some products that may interact with this drug include: other drugs that can cause bleeding/bruising (including antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen, "blood thinners" such as warfarin).

Taking MAO inhibitors with his medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for 2 weeks before and at least 5 weeks after treatment with this medication. Ask your doctor when to start or stop taking this medication.

This medication can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include pimozide, thioridazine, vinblastine, antiarrhythmics (such as propafenone, flecainide), tricyclic antidepressants (such as desipramine, imipramine), among others.

Aspirin can increase the risk of bleeding when used with this medication. However, if your doctor has directed you to take low-dose aspirin for heart attack or stroke prevention (usually at dosages of 81-325 milligrams a day), you should continue taking it unless your doctor instructs you otherwise.

The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including other SSRIs such as citalopram/paroxetine, SNRIs such as duloxetine/venlafaxine), tryptophan, among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and opioid pain relievers (such as codeine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

This medication may interfere with certain medical/laboratory tests (including brain scan for Parkinson's disease), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.