Intro
Brand Name: Celexa
Class: SSRI
MOA: Selective Serotonin Reuptake Inhibitor
Indications
FDA indications: MDD in adults
Off-Label uses: PMDD, GAD, Panic Disorder, Social Anxiety Disorder, PTSD, OCD
Dosing
Forms: Tablet: 10, 20 (scored), 40 (scored) Solution: 10mg/5mL
Starting: 20mg qDay; Increase by 20mg/day after 1 week
Maintenance: 20-40mg qDay
Max: 40mg qday, single dose administration
Pharmacokinetics
Half-life: 23-45 hr
Inhibits: CYP2D6 (weakly)
Substrate of: CYP3A4, CYP2C19
->If pt on CYP2C19 inhibitor (e.g. omeprazole), Citalopram levels will go up. Consider max dose of 20mg qDay
Side Effects
Serious: Serotonin Syndrome, SIADH
Notable: QT prolongation (FDA warning in 2012), Sexual dysfunction (dose dependent, delayed ejaculation, anorgasmia), GI (n/v/d, dec appetite), Sedation, Antiplatelet effect
Gems
-Many patients respond better to 40mg than 20mg
-May be less well tolerated than escitalopram
-Escitalopram may be preferred due to decreased risk of QT prolongation
-Citalopram is a racemic mixture, containing both the R-enantiomer (minimal antidepressant activity, causes QT prolongation) and S-enantiomer (active; high selectivity for SERT) of citalopram. Escitalopram is only the S-enantiomer of citalopram (hence “es”-citalopram)
=>Because of this, Celexa 20mg is roughly the same as Lexapro 10mg
-Not much reason to start Celexa over Lexapro. Most pts on Celexa are on it because Lexapro was more expensive at the time, however Lexapro went generic in 2012.
-If a higher dose of Citalopram over 40mg is needed, initiate Lexapro
Special Populations
Renal Impairment: No dose adjustment in mild-moderate
Hepatic Impairment: Do not exceed 20mg/day
Elderly (60y/o +): Do not exceed 20mg/day
Adolescents: use with caution, observe for bipolar or SI
Breast feeding: Some drug found in mother’s breast milk
References:
Prescriber’s Guide: Stahl’s Essential Psychopharmacology