Drug Class: Antidepressant, SSRI

Table of Contents


Prozac (fluoxetine) is a selective serotonin reuptake inhibitors (SSRI) antidepressant used to treat depression, OCD (obsessive compulsive disorder), panic, anxiety and bulimia, an eating disorder. It works by restoring the balance of a chemical in the brain (serotonin) by blocking its reuptake into the nerve cells.

Appetite, mood, sleep, and energy level may improve while using Prozac. This medication may help restore an interest in daily living. It may also decrease panic attacks, as well as anxiety, fear and unwanted thoughts.

Your doctor may have prescribed this medicine to treat other conditions as well.

This information is for educational purposes only. Not every known side effect, adverse effect, or drug interaction is in this database. If you have questions about your medicines, talk to your health care provider.

How to Take It

This medicine should be taken about the same time each day (with the exception of the once weeky product). The best time to take this medicine is in the morning with breakfast. This medicine may take up to 4 weeks to reach full effect, but you may see symptoms of depression improving in 1 to 2 weeks.

Side Effects

Side effects that may occur while taking this medicine include:

  • nervousness
  • anxiety
  • nausea
  • sweating
  • loss of appetite
  • sexual problems
  • trouble sleeping

Contact your doctor immediately if you experience:

  • large pupils
  • bruising easily
  • change in amount of urine
  • eye pain
  • stools become black, bloody or tarry
  • changes in sexual ability or decreased sex drive
  • severe mental/mood changes, including unusual high energy, agitation or thoughts of suicide)
  • muscle weakness
  • fainting
  • muscle spasm
  • seizures
  • shakiness (tremor)
  • unusual weight loss

Warnings & Precautions

  • DO NOT use this medication if you take pimozide or thioridazine or if you are being treated with methylene blue injections.
  • Tell your doctor if you are taking any other antidepressants, e.g., Desyrel, Viibryd, Pexeva, Lexapro, Celexa, Cymbalta, Effexor, Luvox, Oleptro, Zoloft, Paxil, or Symbyax.
  • This medication may induce dizziness or drowsiness. Do not use machinery or drive until you are sure you can perform such activities safely.
  • DO NOT drink alcohol while taking this medication.
  • Tell your doctor if you have thoughts about suicide when you start taking this medication. Family members and caregivers should pay attention to your mood or symptoms.
  • If you have taken an MAO inhibitor in the past two weeks, DO NOT use this medication.
  • For an overdose, seek medical attention immediately. For non-emergencies, contact your local or regional poison control center at 1-800-222-1222.

Drug Interactions

Do not take this medicine with thioridizine, or within 5 weeks of taking Prozac.

Medicines called MAO inhibitors should not be taken while taking fluoxetine.

St. John’s Wort should be avoided while taking this medicine due to the additive effects of serotonin.

Dosage & Missed Dose

Prozac is usually taken once a day and may be taken with or without food. It should be taken exactly as prescribed by your doctor.

Prozac is available in liquid, capsules (in doses of 10 mg, 20 mg, and 40 mg) and tablets (in doses of 10 mg, 20 mg, 40 mg, and 60 mg.)

It is also available in delayed-release capsules, which are available in 90 mg doses, to be administered once a week. This capsule should be swallowed whole, with or without food.

You may need a lower dose if you are 65 or older.

If you miss a dose, take your next dose as soon as you remember. If it is time for your next dose, skip the missed dose and go back to your regular schedule. Do not double doses or take extra medicine to make up for the missed dose.


Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (preferably not in the bathroom). Throw away any medication that is outdated or no longer needed.


This medication should be used only when clearly needed during pregnancy. It may harm an unborn baby. Discuss the benefits and risks immediately with your doctor regarding use of this medication during pregnancy.

More Information

For more information, talk to your doctor, pharmacist or health care provider, or you can visit this website, https://www.nlm.nih.gov/medlineplus/druginfo/meds/a689006.html for additional information from the manufacturer of this drug.