FLUOXETINE oral

Last updated: November 2021


Prescription under medical supervision

Therapeutic action

– Antidepressant, selective serotonin re-uptake inhibitor (SSRI)

Indications

– Major depression
– Generalised anxiety
– Severe post-traumatic stress disorder

Forms and strengths

– 20 mg capsule

Dosage

– Major depression
Adult: 20 mg on alternate days for one week, then 20 mg once daily. In case of insufficient response after 3 weeks, increase up to 40 mg daily max.

– Generalised anxiety, severe post-traumatic stress disorder
Adult: 20 mg once daily

Duration

Major depression: at least 9 months. Discontinue treatment gradually (e.g. half dose once daily for 2 weeks then on alternate days for 2 weeks). If signs of relapse or withdrawal occur, increase the dose then decrease it more gradually.
Generalised anxiety, severe post-traumatic stress disorder: 2 to 3 months after symptoms resolve. Discontinue treatment gradually (over at least 2 weeks). 

Contra-indications, adverse effects, precautions

– Administer with caution and monitor use in patients with epilepsy, diabetes, hepatic impairment (reduce dose or frequency of administration) or severe renal impairment; history of: gastrointestinal bleeding, bipolar disorders, suicidal ideation or closed-angle glaucoma.
– May cause:
• gastrointestinal disturbances, drowsiness, fatigue, headache, dizziness, seizures, sexual dysfunction, blurred vision, hyponatraemia especially in older patients;
• mental disorders: anxiety, insomnia, agitation, aggressive behaviour, suicidal ideation;
• withdrawal symptoms very frequent if discontinued abruptly: dizziness, paraesthesia, nightmares, anxiety, tremors and headaches.
– Avoid combination with:
• alcohol (risk of drowsiness); aspirin, NSAIDs and warfarin (risk of bleeding);
• serotonergic drugs: other SSRI, tricyclic antidepressants, ondansetron, tramadol, etc. (risk of serotonin syndrome).
– Monitor combination with: carbamazepine, phenytoin, risperidone (increased plasma concentrations), drugs which lower the seizure threshold (antipsychotics, mefloquine, etc.). 
Pregnancy: re-evaluate whether the treatment is still necessary; if it is continued, maintain fluoxetine at effective dose or consider switching to another SSRI if the woman plans to breast-feed. Observe the neonate (risk of agitation, tremors, hypotony, respiratory difficulties, sleeping disorders, etc.) if the mother was under treatment in the 3rd trimester. If treatment starts during pregnancy, preferably use sertraline.
Breast-feeding: avoid; consider switching to sertraline or if not available, paroxetine.

Remarks

– Do not open the capsules.
– It is necessary to wait at least 2 to 3 weeks before assessing the antidepressant effect. This must be explained to the patient.
Storage: below 25 °C -  -