Other Brands/Names

Antiprestin, Kalxetin, Courage, Lodep, Deprezac, Nopres, Deproz, Oxipres, Elizac, Prozac, Floxet, Zac, Foransi, Zactin.

How It Works

Fluoxetine is an antidepressant classified under selective serotonin reuptake inhibitors (SSRIs). Although the exact mechanism of SSRIs is not fully understood, they are believed to work by blocking the reuptake of serotonin, thereby increasing its levels in the brain. This helps regulate mood, emotions, and certain behaviors.

Indications

This medication is used to treat:

• Major depressive disorder

• Bulimia nervosa

• Panic disorder, with or without agoraphobia

• Premenstrual dysphoric disorder (PMDD)

• Obsessive-compulsive disorder (OCD)

Contraindications

Fluoxetine should not be used in the following cases:

• Allergy to fluoxetine or any of its ingredients

• Epilepsy

• Kidney failure with glomerular filtration rate (GFR) <10 ml/minute

It must also not be taken together with monoamine oxidase inhibitors (MAOIs), such as IV methylene blue, linezolid, or iproniazid, or with thioridazine.

Side Effects

Like many medications, fluoxetine may cause side effects, though not all patients experience them. This drug should only be used under a doctor’s prescription. Possible side effects include:

• Suicidal thoughts or attempts (especially in children, adolescents, and young adults)

• Manic or hypomanic symptoms

• Seizures

• Central nervous system depression

• Headaches, dizziness, drowsiness, tremors

• Psychomotor agitation, sleep disturbances, tension, abnormal dreams, attention difficulties.

• Anorexia bone fractures.

• Glucose imbalances (hypoglycemia or hyperglycemia).

• Hyponatremia.

• Cardiovascular and respiratory: palpitations, shortness of breath.

• Digestive system: nausea, vomiting, diarrhea, indigestion, dry mouth.

• Reproductive system: reduced libido, erectile dysfunction, ejaculation disorders.

Potentially life-threatening side effects:

• Serotonin syndrome or neuroleptic malignant syndrome (NMS)-like symptoms

• Severe bleeding

• Dangerous hyponatremia

• Serious allergic reactions and rashes

Types

This medication is available in capsules as well as tablets with strengths of 10 mg and 20 mg.

Dosage

Bulimia nervosa

Adults: 60 mg daily, taken as a single dose or divided doses.

Major depressive disorder

• Adults: Initial dose of 20 mg once daily (single or divided). If needed, dosage may be adjusted within 3–4 weeks depending on response. Maximum: 60 mg per day. Treatment should continue for at least 6 months.

• Children (≥8 years): Oral solution/dispersible tablets: Start with 10 mg once daily, which may be increased to 20 mg once daily after 1–2 weeks. Doses should be tailored individually and kept at the lowest effective amount.

• Elderly: Start at 20 mg daily (single or divided). Dose can be increased slowly within 3–4 weeks depending on response. Maximum: 40 mg daily.

Individual dose adjustments and maintain at the lowest effective dose.

Panic disorder with or without agoraphobia

• Adults: Start with 10 mg daily, increasing to 20 mg daily after 1 week. Dose may be raised further after several weeks if symptoms persist. Maximum: 60 mg daily.

• Elderly: May require lower or less frequent doses.

Premenstrual dysphoric disorder (PMDD)

Adults: 20 mg daily, either continuously (throughout the menstrual cycle) or intermittently (from 14 days before menstruation until the first day of menstruation). Continue therapy for 6 months, then reassess.

Safety

Pregnancy

Category Z. Fluoxetine has been associated with serious risks, including heart defects, postpartum bleeding, pulmonary hypertension in the fetus, and neonatal withdrawal or toxicity when taken in the third trimester. It must not be used without strict medical supervision.

Breastfeeding Mother

Fluoxetine passes into breast milk and should not be taken unless approved by a doctor.

Drug Interactions

Fluoxetine increases bleeding risk when combined with warfarin, other anticoagulants, aspirin, NSAIDs, or atypical antipsychotics (such as clozapine or phenothiazines).

This drug may elevate serum levels of benzodiazepines and increase blood concentrations of phenytoin, haloperidol, and carbamazepine.

Interactions can be dangerous, especially with other serotonergic agents (triptans, TCAs, fentanyl, lithium, tramadol, buspirone, tryptophan) or with MAOIs, as these combinations may trigger serotonin syndrome.

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