fluoxetine PROZAC

Class: SSRI
FDA Indications: MDD, OCD, Bulimia Nervosa, Panic Disorder, Treatment Resistant Depression, Depressive Episodes Assoc W/ Bipolar I Disorder, Myoclonus, PMDD
Off-Label Use: Premature Ejaculation, Fibromyalgia, Neurocardiogenic Syncope, Borderline Personality Disorder, Bulimia Nervosa, PTSD, Raynaud Phenomenon, Social Anxiety
Prescribing
Forms: 10, 20, 40mg capsule; 10, 20, 60mg tablet; 20mg/5mL po soln
Dose Range: 10-80 mg/day
Starting: 20 mg/day qam; may ↑ after several weeks by 20 mg/day increments; max 80 mg/day
Stopping: Because of long t½ taper is rarely needed as fluoxetine "auto-tapers"

NAMI drug fact sheet

Precautions
Contraindications: Concomitant use of MAOIs
Serious Side Effects: Serotonin syndrome; ↑ risk of SI in children and young adults; may impair platelet aggregation; SIADH
Conditional Risk of TdP, Drugs to Avoid in Congenital Long QT
Side Effects: sedation/somnolence, decreased libido, xerostomia, increased sweating, tremor, diarrhea, nausea, insomnia, anorexia
Pharmacodynamics
1° MOA: Selective serotonin reuptake inhibitor
Target: SERT, 5-HT2C (antagonist)
Pharmacokinetics
t½: 60 (24-144)° TMAX: 6-8°
Substrate of: 2D6; 3A4
Inhibits: 2D6, 3A4; Induces:
Active Metabolites: Norfluoxetine (t½ 200-330°)
DDIs
  • - DO NOT CO-PRESCRIBE WITH MAOIs (need a 5-week washout period)
  • - 2D6 inhibitors can ↑ its serum levels
  • - fluoxetine's 2D6/3A4 inhibition can ↑ levels of 2D6/3A4 substrates
Misc
  • - only antidepressant specifically approved for use in children (depression and OCD)
  • - only SSRI with an FDA indication for eating disorders
  • - long t½ of drug & its metabolites means dose Δ's won't be reflected in plasma levels for weeks
  • - relatively safe in CV patients
  • - 5HT2C antagonism has a net disinhibiting effect on NE & DA, which may account for its "activating" effects
  • - more prone to result in weight loss compared to other SSRIs
  • - nonlinear pharmacokinetics; inhibits its own metabolism
  • - ∅ QTc prolongation
Special Populations

Category C—Has the most data supporting its safety.

Highest RID (1.6-14.6%) among the SSRIs; ∅AE's have been reported for majority of fluoxetine-exposed infants; conflicting reports about effects on growth curves

Start low with dosage ↑ of 10 & 20 mg q several weeks; can cause agitation, sleep disturbances, & ↑CNS stimulation in elderly.

Use with caution in patients with severe renal impairment


Administer a lower dose or less frequent dosing interval due to long t½

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Last updated January 22 2018 19:18:05. Disclaimer: This website does not provide medical advice, nor is it a substitute for clinical judgment.