Fluoxetine HCl (Prozac)

  • Generic name: Fluoxetine hydrochloride
  • Brand name: Prozac, Sarafem, Selfemra
  • Drug class: Selective Serotonin Reuptake Inhibitors (SSRIs)

What is Fluoxetine used for?

  • Depression
  • Binge eating and vomiting in bulimia nervosa
  • Obsessive-compulsive disorder
  • Panic attacks with or without agoraphobia
  • Premenstrual dysphoric disorder (PMDD) and premenstrual syndrome (PMS)
  • Treatment-resistant or bipolar I depression in combination with olanzapine


  • Don't combine with antipsychotic thioridazine (Mellaril) due to the risk of life-threatening ventricular arrhythmias. Minimum of 5 weeks should be allowed between stopping Fluoxetine and starting thioridazine.
  • Serious, sometimes fatal, reactions may occur during concomitant use with MAO inhibitors. You must wait at least 14 days after stopping an MAO inhibitor before you can take fluoxetine. You must wait 5 weeks after stopping fluoxetine before you can take an MAOI.

Fluoxetine and Depression

Fluoxetine has a slower onset of antidepressant effect than other antidepressants. So, in situations such as in severe depression, when the fast therapeutic effect is particularly important, fluoxetine may be inappropriate.

Fluoxetine is activating, so it is a good choice for depressed patients with hypersomnia or psychomotor retardation.

Depression in children and adolescents

Fluoxetine is the only antidepressant with FDA-approved labeling for the treatment of depression in children (over 8 years of age) and teenagers. Research shows fluoxetine combined with cognitive behaviour therapy works well for teenagers with moderate or severe depression2.

There is a small risk that children taking fluoxetine might hurt themselves. Self-harm thoughts are less likely to happen if they have a counseling treatment at the same time.

Further reading:

Fluoxetine (Prozac) dosage for depression:

Adults: Initially, 20 mg/day (in the morning). Wait a few weeks and, if needed, the dose may be gradually increased up to a maximum of 80 mg/day.

Children 8 years and older: Initially, 10 mg or 20 mg daily. Children starting at 10 mg may have their dose increased to 20 mg a day after 1 week. Underweight children may remain at the 10 mg daily.

When is the best time of day to take fluoxetine?

The best time to take fluoxetine (Prozac) is in the morning, because it is activating.


  • 1. Fluoxetine monograph Reference guide from the American Society of Health-System Pharmacists.
  • 2. March J, Silva S, Petrycki S, et al. Fluoxetine, cognitive-behavioral therapy, and their combination for adolescents with depression: Treatment for Adolescents With Depression Study (TADS) randomized controlled trial. JAMA. 2004 Aug 18;292(7):807-20. PubMed
  • 3. Nordeng H, Bergsholm Y, Bohler E, Spigset O. The transfer of selective serotonin reuptake inhibitors to human milk. Tidsskrift for den Norske Laegeforening. 2001;121:199–203. PubMed
  • 4. Chambers CD, Johnson KA, Dick LM, Felix RJ, Jones KL. Birth outcomes in pregnant women taking fluoxetine. N Engl J Med. 1996 Oct 3;335(14). Full article

Last updated: February, 2015

Advanced Consumer Info


fluoxetine hcl

  • Pregnancy Category: C. Studies show that women who take fluoxetine during pregnancy do not have an increased risk of spontaneous pregnancy loss or fetal anomalies. However, use of fluoxetine in the third trimester increases the risk for perinatal complications 4.
  • Breastfeeding: Relatively high concentrations of fluoxetine have been detected in breast milk and infant plasma3.
  • Elimination half-life: fluoxetine has a unique long half-life of 2-4 days and its active metabolite, norfluoxetine, has a half-life of 4-16 days.
  • Its long half-life may wipe off the effect of missed or reduced doses and makes it easier to discontinue than any of the other SSRIs.
  • Mechanism of action: Fluoxetine blocks neuronal reuptake of serotonin.