FLUOXETINE

Indications & Dose:

Major depression

• BY MOUTH

Adult: Initially 20 mg daily, dose is increased after 3–4 weeks if necessary, and at appropriate intervals thereafter, daily dose may be administered as a single or divided dose; maximum 60 mg per day

Elderly: Initially 20 mg daily, dose is increased after 3–4 weeks if necessary, and at appropriate intervals thereafter, daily dose may be administered as a single or divided dose, usual maximum dose is 40mg daily but doses up to 60mg daily can be used

Bulimia nervosa

• BY MOUTH

Adult: 60 mg daily, daily dose may be administered as a single or divided dose

Elderly: Up to 40 mg daily, daily dose may be administered as a single or divided dose, usual maximum dose is 40 mg daily but doses up to 60 mg daily can be used

Obsessive-compulsive disorder

•  BY MOUTH

Adult: 20 mg daily, increased if necessary up to 60 mg daily, daily dose may be administered as a single or divided dose, dose to be increased gradually, review treatment if inadequate response after 10 weeks; maximum 60 mg per day

Elderly: 20 mg daily, increased if necessary up to 40 mg daily, daily dose may be administered as a single or divided dose, dose to be increased gradually, review treatment if inadequate response after 10 weeks, usual maximum dose is 40 mg daily but doses up to 60 mg daily can be used 

Contraindications:

Side Effects:

Cautions:

Precautions:

Renal or hepatic function impairment, elderly, children, bipolar affective disorder, seizure disorder, suicidal ideation, diabetes 

Interaction:

Drugs

Benzodiazepines (alprazolam; diazepam): Probable   inhibition of metabolism (CYP3A4) leg to accumulation of diazepam and alprazolam

Beta-blockers (metroprolol, propranolol, sotalol): Inhibition of metabolism (CYP2D6) leads to increased plasma concentrations of selective beta blockers and potential cardiac toxicity; atenolol may be safer choice

Buspirone: Reduced therapeutic effect of both drugs; possible seizures

Carbamazepine: Inhibition of hepatic metabolism of carbamazepine, but the formation of carbamaxepine epoxide is not inhibited, caritributing to increased toxicity

Cyproheptadine: Serotonin antagonist may partially reverse antidepressant and other effects

Dexfenfluramine: Duplicate effects on inhibition of serotonin reuptake; inhibition. of dexfenfluramine metabolism (CYP2D6) exaggerates effect; both mechanisms increase risk of serotonin syndrome

Dextromethorphan: Inhibition of dextrometherphan’s metabolism (CYP2D6) by fluoxetine and additive serotonergic effects

Diuretics, loop (bumetanide, furosernide, torsemide): Possible additive hyponatremia; 2 fatal case reports with furosemide and fluoxetine

Fenfluramine: Duplicate effects an inhibition of serotonin reuptake; inhibition of dexfenduramine metabolism (CYP2D6) exaggerates effect; both mechanisms increase risk of serotonin syndrome

Haloperidol: Inhibition of haloperidol’s metabolism (CYP2D6) may increase risks of extrapyramidal symptoms

HMG-Co A reductase inhibitors (atorvastatin, lovastatin, simvastatin): Inhibition of statin metabolism (CYP3A4), by fluoxetine, may lead to rhabdomyolysis

Lithium: Neurotoxicity (tremor, confusion, ataxia, dizziness, dysarthcia, and abscence seizures) reported in patients receiving this combination; mechanism unknown

MAOI’s (isocarboxazid, phenelzine, tranyleypromine): Increased CNS serotonergic effect has been associated with severe or fatal reactions with this combination

Non-sedating antihistamines (astemizole, terfenadine): Metabolite, norfluoxetine, may inhibit metabolism (CYP3A4) for detoxifying these antihistamines; cardiac rhythm disturbance

Phenytoin: Inhibition of metabolism and phenytoin toxicity

Selegiline: Sporadic cases of mania and hypertension

Tricyclic antidepressants (clomipramine, desipramine, doxepin, imfpramine, nortriptylline, trazodane): Marked increases in tricyclic antidepressant levels due to inhibition of metabolism (CYP2D6)

Tryptophan: Additive serotonergic effects 

Warnings:

Adverse Effects:

Lactations:

Pregnancy ; excreted into breast milk; use caution in nursing mothers

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

CNS: Anxiety, apathy, decreased libido, delusions, dizziness, drowsiness, euphoria, fatigue, hallucinations, headache, insomnia, nervousness, psychosis, seizures, serotonergic syndrome (anxiety, hyperreflexia, confusion), tremor

CV: Hot flushes, palpitations

EENT: Blurred vision, visual disturbance

GI: Anorexia, constipation, diarrhea, dry mouth, dyspepsia, hyperbilirubinemia, loose stools, nausea, taste changes

GU: Painful menstruation, sexual dysfunction

METAB: Altered glycemic control, hypoglycemia

MS: Joint or muscle pain

SKIN: Pruritus, rash, sweating

MISC: Weight loss 

Patient And Carer Advice: