II. Mechanism
III. Indications
IV. Background
- Capsules are less expensive than tablets, and both are generic
V. Safety
- Avoid in Lactation
- Fluoxetine levels are not high in Breast Milk
- However Fluoxetine is associated with more adverse effects in infants than other SSRIs
- Teratogenic if patient becomes pregnant again (therefore generally avoided in Lactation)
- Pregnancy Category C
- Well studied in pregnancy, but data in 2015 showed association with cardiac defects
- Association with VSD, right ventricular outflow tract obstruction cardiac defects, and Craniosynostosis
- Berard (2015) Br J Clin Pharmacol +PMID:26613360
VI. Preparations
- Capsules: 10, 20 and 40 mg
- Tablets (scored): 10 mg
- Oral solution: 20 mg/5 ml
- Long-acting Prozac Weekly preparation: 90 mg capsules
VII. Dosing
- Daily
- Start
- Children (age 7 to 18 years): 5-10 mg orally daily
- Adults: 20 mg orally daily
- Elderly: 10 mg orally daily
- Titrate
- Avoid increasing dose more often than monthly
- Maximum
- Children (age 7 to 18 years): 60 mg
- Adults: 80 mg orally daily
- Maximal dose often required in Bulimia and OCD
- Start
- Weekly (Delayed Release or DR formulation)
- Prozac Weekly 90 mg once weekly
- Equivalent to 20 mg orally daily
- Prozac Weekly 90 mg once weekly
VIII. Pharmacokinetics
- Half Life is Very Long! (48 to 72 hours; duration 7-9 days)
- Therapeutic Blood level 163-560 ng/ml
IX. Drug Interactions
- See Serotonin Syndrome
- Stop for 5 weeks before starting MAO Inhibitor
- Metabolized by Cytochrome P450-2D6 and 2C9
- Strong Cytochrome P450-2D6 Inhibitor
- Moderate Cytochrome P450-2C19 Inhibitor (increases Phenytoin levels)
- Highly Protein bound
- Interacts with other Protein bound medications
- Raises the following drug levels
- Warfarin (Coumadin) and increased INR
- Tricyclic Antidepressants
- Carbamazepine (Tegretol)
- Phenytoin (Dilantin)
X. Adverse Effects: General
XI. Adverse Effects: Pregnancy
- Earlier safety data
- Major Fetal Structural abnormality
- No Change (5.5% versus 4% for Placebo)
- Minor Fetal Structural abnormality
- Significant Association (15.5% vs 6.5% for Placebo)
- Fluoxetine also associated with
- Preterm Labor
- NICU admissions
- Low birth weight
- References: Study of n=482
- Major Fetal Structural abnormality
- Safety data in 2015
- Fluoxetine has been well studied in pregnancy, but data in 2015 showed association with cardiac defects
- Berard (2015) Br J Clin Pharmacol +PMID:26613360 [PubMed]
XII. Resources
XIII. References
- (2023) Med Lett Drugs Ther 62(1592): 25-32
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 38-9
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
Images: Related links to external sites (from Bing)
Related Studies
fluoxetine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
FLUOXETINE 20 MG/5 ML SOLUTION | Generic | $0.29 per ml |
FLUOXETINE DR 90 MG CAPSULE | Generic | $29.43 each |
FLUOXETINE HCL 10 MG CAPSULE | Generic | $0.03 each |
FLUOXETINE HCL 10 MG TABLET | Generic | $0.11 each |
FLUOXETINE HCL 20 MG CAPSULE | Generic | $0.03 each |
FLUOXETINE HCL 20 MG TABLET | Generic | $0.13 each |
FLUOXETINE HCL 40 MG CAPSULE | Generic | $0.07 each |
FLUOXETINE HCL 60 MG TABLET | Generic | $0.56 each |
prozac (on 1/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
PROZAC 20 MG PULVULE | Generic | $0.03 each |
PROZAC 40 MG PULVULE | Generic | $0.07 each |