FLUOXETINE HYDROCHLORIDE  (flu'ox-e-tine)  Prozac, Prozac Weekly, Sarafem Classifications: psychotherapeutic agent; selective serotonin reuptake inhibitor (ssri); antidepressant; Therapeutic: antidepressant; ssri Pregnancy Category: C
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Availability
10 mg tablets; 10 mg, 20 mg capsules; 20 mg/5 mL solution; 90 mg sustained release capsules (Prozac Weekly)
Action
A selective serotonin reuptake inhibitor (SSRI). Antidepressant effect is presumed to be linked to its inhibition of CNS neuronal
uptake of serotonin, a neurotransmitter.
Therapeutic Effect
Effectiveness may take from several days to 5 wk to develop fully. Drug has antidepressant, antiobsessive-compulsive, and
antibulimic actions.
Uses
Depression, geriatric depression, obsessive-compulsive disorder (OCD), bulimia nervosa, premenstrual dysphoric disorder.
Unlabeled Uses
Obesity.
Contraindications
Hypersensitivity to fluoxetine or other SSRI drugs; concurrent administration with MAOIs, or thioridazine; pregnancy (category C), children <7 y for OCD, children <8 y for depression; suicidal ideation.
Cautious Use
Hepatic and renal impairment, renal failure, abrupt discontinuation, anorexia nervosa, mania, bleeding; hyponatremia, cardiac
disease, dehydration, diabetes mellitus, patients with history of suicidal ideations; seizure disorders, ECT, hepatic disease.
Older adults may require dose adjustments; lactation.
Route & Dosage
Depression, Obsessive-Compulsive Disorder Adult: PO 20 mg/d in a.m., may increase by 20 mg/d at weekly intervals (max: 80 mg/d); 20 mg/d in a.m.; when stable may switch to 90
mg sustained release capsule qwk (max: 90 mg/wk) Child (>7 y): PO 1020 mg/d in a.m. (max: 60 mg/d for OCD) Geriatric: PO Start with 10 mg/d
Premenstrual Dysphoric Disorder Adult: PO 1020 mg q.d. (max: 60 mg/d)
Bulimia Nervosa Adult: PO 60 mg q.d.
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Administration
Oral
- Give as a single dose in morning. Give in two divided doses; one in a.m. and one at noon to prevent insomnia, when more than
20 mg/d prescribed.
- Provide suicidal or potentially suicidal patient with small quantities of prescription medication.
- Monitor for worsening of depression or expression of suicidal ideations.
- Store at 15°25° C (59°77° F).
Adverse Effects (≥1%)
CNS: Headache, nervousness, anxiety, insomnia, drowsiness,
fatigue, tremor, dizziness.
CV: Palpitations, hot flushes, chest pain.
GI: Nausea, diarrhea, anorexia, dyspepsia, increased appetite, dry mouth.
Skin: Rash, pruritus, sweating, hypersensitivity reactions.
Special Senses: Blurred vision.
Body as a Whole: Myalgias, arthralgias, flu-like syndrome, hyponatremia.
Urogenital: Sexual dysfunction, menstrual irregularities.
Interactions
Drug: Concurrent use of
tryptophan may cause agitation, restlessness, and GI distress;
mao inhibitors,
selegiline may increase risk of severe hypertensive reaction and death; increases half-life of
diazepam; may increase toxicity of
tricyclic antidepressants;
amphetamines,
cilostazol, nefazodone, pentazocine, propafenone, sibutramine, tramadol, venlafaxine may increase risk of serotonin syndrome; may inhibit metabolism of
carbamazepine, phenytoin, ritonavir; increased ergotamine toxicity with
dihydroergotamine, ergotamine. antipsychotics like
pimozide can cause QT prolongation.
Herbal: St. John's wort may cause
serotonin syndrome.
Pharmacokinetics
Absorption: 6080% from GI tract.
Onset: 13 wk.
Peak: 48 h.
Distribution: Widely distributed, including CNS.
Metabolism: In liver to active metabolite, norfluoxetine.
Elimination: >80% in urine; 12% in feces.
Half-Life: Fluoxetine 23 d, norfluoxetine 79 d.
Nursing Implications
Assessment & Drug Effects
- Monitor children and adolescents for changes in behavior and suicidal ideation.
- Use with caution in the older adult patient or patient with impaired renal or hepatic function (may need lower dose).
- Use with caution in anorexic patient, since weight loss is a possible side effect.
- Monitor for S&S of anaphylactoid reaction (see Appendix F).
- Lab tests: Periodic serum electrolytes; monitor closely plasma glucose in diabetes.
- Monitor serum sodium level for development of hyponatremia, especially in patients who are taking diuretics or are otherwise
hypovolemic.
- Monitor diabetics for loss of glycemic control; hypoglycemia has occurred during initiation of therapy, and hyperglycemia
during drug withdrawal.
- Monitor for S&S of improved affect. Requires approximately 23 wk for therapeutic effects to be felt.
- Weigh weekly to monitor weight loss, particularly in the older adult or nutritionally compromised patient. Report significant
weight loss to physician.
- Observe for and promptly report rash or urticaria and S&S of fever, leukocytosis, arthralgias, carpal tunnel syndrome, edema,
respiratory distress, and proteinuria. Drug may have to be discontinued or adjunctive therapy instituted with steroids or
antihistamines.
- Observe for dizziness and drowsiness and employ safety measures (up with assistance, side rails, etc.) as indicated.
- Monitor for and report increased anxiety, nervousness, or insomnia; may need modification of drug dose.
- Monitor for seizures in patients with a history of seizures. Use appropriate safety precautions.
- Supervise patients closely who are high suicide risks; especially during initial therapy.
- Monitor patients with hepatic or renal impairment carefully for S&S of toxicity (e.g., agitation, restlessness, nausea, vomiting,
seizures).
Patient & Family Education
- Notify physician of intent to become pregnant.
- Notify physician of any rash; possible sign of a serious group of adverse effects.
- Do not drive or engage in potentially hazardous activities until response to drug is known; especially if dizziness noted.
- Monitor blood glucose for loss of glycemic control if diabetic.
- Note: Drug may increase seizure activity in those with history of seizure.