ANXETIN 20/MG CAP 20/CAP

Indications

Approved Uses

Major depressive disorder (MDD), obsessive-compulsive disorder (OCD), panic disorder, bulimia nervosa, premenstrual dysphoric disorder (PMDD), bipolar depression (as adjunct with olanzapine)

Off-Label Uses

Common off-label uses include generalized anxiety disorder, PTSD, social anxiety disorder, binge-eating disorder, and premature ejaculation.

Dosage & Administration

Dosing by Condition

Major depressive disorder: start 20 mg once daily; typical range 20-60 mg/day; max 80 mg/day. OCD: start 20 mg/day; typical range 20-60 mg/day; max 80 mg/day. Panic disorder: start 10 mg/day then increase to 20 mg/day; max 60 mg/day. Bulimia nervosa: 60 mg/day. PMDD: 20 mg/day either continuously or intermittently (luteal-phase dosing).

Initial Dose

20 mg once daily in the morning.

Maintenance Dose

20-60mg once daily

Maximum Dose

80 mg per day for depression and OCD; 60 mg per day for panic disorder and bulimia.

Children's Dosage

OCD (ages 7-17): Initial 10mg/day, may increase to 20-60mg/day. MDD (ages 8-18): Initial 10mg/day, may increase to 20mg/day after 1 week. Lower weight children: 10-20mg/day. Not approved for children under 7 years

Dose Adjustment Notes

If response is inadequate, increase gradually after several weeks; use lower or less frequent dosing in hepatic impairment and consider lower dosing in the elderly; when switching with MAOIs: wait at least 14 days after stopping an MAOI before starting fluoxetine, and wait at least 5 weeks after stopping fluoxetine before starting an MAOI.

How to Take

Swallow the capsule whole with water; may be taken with or without food; usually taken once daily in the morning (if activating/insomnia occurs, avoid late-day dosing).

Side Effects

Common Side Effects

Nausea, headache, insomnia, somnolence/drowsiness, diarrhea, dry mouth, anxiety/nervousness, tremor, sweating, decreased appetite/weight loss, fatigue/weakness, and sexual dysfunction (e.g., decreased libido, delayed ejaculation/anorgasmia).

Side Effect Frequency

Very common (≥10%): nausea, headache, insomnia, diarrhea; sexual dysfunction is common to very common depending on definition/study. Common (1-10%): anxiety/nervousness, decreased appetite/anorexia, tremor, dizziness, dry mouth, dyspepsia, sweating, abnormal dreams, fatigue/somnolence. Rare/serious: hyponatremia/SIADH, seizures, mania/hypomania, serotonin syndrome, abnormal bleeding, angle-closure glaucoma; QT prolongation is uncommon/rare and not a typical frequent effect at usual doses.

Safety & Warnings

Contraindications

Contraindicated with: (1) concomitant use of MAOIs or within 14 days of stopping an MAOI, and do not start an MAOI within 5 weeks of stopping fluoxetine; (2) concomitant use with thioridazine; (3) concomitant use with pimozide; (4) known hypersensitivity to fluoxetine.

Warnings & Precautions

Key warnings/precautions: monitor for clinical worsening/suicidality (especially children/adolescents/young adults) during initiation and dose changes; risk of serotonin syndrome with serotonergic drugs; screen for bipolar disorder and monitor for mania/hypomania; increased bleeding risk with NSAIDs/antiplatelets/anticoagulants; hyponatremia/SIADH risk (higher in elderly/diuretics); seizure risk (use caution in seizure disorders); consider QT prolongation risk and avoid interacting QT-prolonging agents; use lower/less frequent dosing in hepatic impairment; taper when discontinuing when feasible.

Age Restriction

Not approved for MDD in children under 8 years or for OCD in children under 7 years

Driving Warning

May Cause Drowsiness

Drug Interactions

Drug Interactions

Major interactions include: MAOIs (contraindicated; serotonin syndrome), linezolid or IV methylene blue (avoid/contraindicated due to serotonin syndrome risk), thioridazine and pimozide (contraindicated; QT prolongation/arrhythmia), other serotonergic agents (e.g., triptans, tramadol, lithium, other SSRIs/SNRIs/TCAs, St John’s wort-serotonin syndrome), anticoagulants/antiplatelets/NSAIDs (increased bleeding), and CYP2D6 substrates with narrow therapeutic index (fluoxetine is a strong CYP2D6 inhibitor-can increase levels of TCAs and some antipsychotics).

Interaction Severity

MAJOR/contraindicated: MAOIs (including linezolid and IV methylene blue) due to serotonin syndrome risk; thioridazine and pimozide due to QT prolongation/arrhythmia risk. MODERATE/clinically significant: other serotonergic agents (e.g., tramadol, triptans, TCAs, lithium, St. John’s wort) and anticoagulants/antiplatelets/NSAIDs (increased bleeding risk); CYP2D6 substrates with narrow therapeutic index (e.g., TCAs, some antipsychotics) may have increased levels.

Food Interaction

No clinically significant food restrictions; may be taken with or without food.

Alcohol Interaction

Avoid

Special Populations

Pregnancy

Category C

Children

OCD (ages 7-17): Initial 10mg/day, may increase to 20-60mg/day. MDD (ages 8-18): Initial 10mg/day, may increase to 20mg/day after 1 week. Lower weight children: 10-20mg/day. Not approved for children under 7 years

Elderly

Start at lower dose (10mg/day), titrate slowly. Monitor for hyponatremia, falls, and drug interactions. Reduced clearance may necessitate lower maintenance doses.

Kidney Impairment

No routine dose adjustment is generally required in renal impairment; use caution and clinical monitoring in severe renal dysfunction.

Liver Impairment

Use a lower dose or less frequent dosing (e.g., reduced dose and/or longer dosing interval such as every other day) in hepatic impairment; use extra caution in severe hepatic disease.

Storage & Patient Advice

Missed Dose

Take the missed dose as soon as remembered the same day; if it is close to the next dose, skip the missed dose and resume the regular schedule; do not double doses.

Stopping the Medicine

Do not stop abruptly without medical advice; tapering is generally recommended, although fluoxetine’s long half-life makes discontinuation symptoms less likely/severe than many other SSRIs.

Overdose

Overdose may cause nausea/vomiting, agitation/CNS excitation, tremor, seizures, tachycardia/arrhythmias (including QT prolongation), somnolence, and serotonin syndrome; management is supportive (airway/breathing/circulation, consider activated charcoal if appropriate, treat seizures, and cardiac/ECG monitoring) and requires urgent emergency evaluation.

Patient Counseling

Take exactly as prescribed (usually once daily in the morning); may take several weeks to feel full benefit; do not stop abruptly without clinician advice; report suicidal thoughts, worsening mood, or unusual behavior changes; avoid combining with other serotonergic products (including St. John’s wort) unless advised and seek urgent care for serotonin syndrome symptoms; use caution with driving if drowsy; limit alcohol; report unusual bleeding/bruising and rash.

Monitoring Requirements

Monitor for worsening depression/suicidal ideation especially at initiation and dose changes; monitor for serotonin syndrome when combined with serotonergic drugs; monitor sodium (hyponatremia/SIADH) in older adults or at-risk patients; monitor weight/appetite; consider bleeding risk when used with NSAIDs/anticoagulants and monitor glucose in diabetics as clinically indicated.

Pharmacology

Mechanism of Action

Selective serotonin reuptake inhibitor (SSRI): inhibits presynaptic serotonin (5‑HT) reuptake, increasing synaptic serotonin; minimal direct affinity for muscarinic, histaminic, or adrenergic receptors compared with TCAs.

Onset of Action

Initial symptom improvement may be seen in 1-2 weeks; full antidepressant effect typically requires 4-6 weeks.

Metabolism

Hepatic metabolism to active norfluoxetine primarily via CYP2D6; other CYPs (notably CYP2C9 and CYP3A4) also contribute.

Excretion

Excreted mainly in urine as metabolites (≈60%); the remainder is excreted in feces (≈15%) with minimal unchanged drug.

Product Information

Available Dosage Forms

For this SFDA product: oral capsule (20 mg). In general fluoxetine is also available in tablets/capsules and oral solution; a delayed-release capsule formulation is not a standard fluoxetine dosage form (that is typical of some other SSRIs).

Composition per Dose

Each capsule: 20mg fluoxetine (as fluoxetine hydrochloride)

Generic Availability

Yes

OTC Alternatives

No OTC alternative

Psych Class

Antidepressant-SSRI

Controlled Substance

No

Reviewed by Al Mujtama Pharmacy Medical Review Team. Last reviewed 10-05-2026