- Selective Serotonin Reuptake Inhibitor (SSRI)
- Minimal effects on other Neurotransmitters
- Citalopram
- Half-Life: 20 to 35 hours
- Bioavailability: 80%
- Peak drug levels: 4 hours
- Escitalopram
- Half-Life: 27-33 hours
- Bioavailability: 80%
- Peak drug levels: 5 hours
- Pregnancy Category C
- Considered safe in Lactation with caution
- Both Citalopram and Escitalopram have acceptably low levels in Breast Milk
- Citalopram and Escitalopram are ACOG L3 (moderately safe in Lactation)
- Citalopram (Celexa)
- Tablets: 10, 20 (scored), 40 (scored)
- Oral Solution: 10 mg/5 ml
- Escitalopram (Lexapro)
- Active isomer of racemic Citalopram
- Tablets: 5, 10 (scored), 20 mg (scored)
- Citalopram (Celexa)
- Starting dose: 20 mg orally daily
- Most effective dose: 40 mg orally daily
- Maximum Dose: 40 mg
- Maximum dose 20 mg in hepatic Impairment or concurrent use of Cytochrome P450 2C19 Inhibitors (see below)
- Escitalopram (Lexapro)
- Starting Dose: 10 mg daily (equivalent to 40 mg Celexa)
- Higher dose at 20 mg is not more effective than 10 mg
- Maximum dose 10 mg in hepatic Impairment or use of Cytochrome P450 2C19 Inhibitors (see below)
- General
- No increased weight gain
- Midway on spectrum between Anxiolytic and anxiogenic
- Similar to Zoloft on this spectrum
- Well tolerated
-
Nausea
- May occur initially but is transient
- Consider decreasing dose to 10 mg initially
- Less Sexual Dysfunction than Prozac, Zoloft, Paxil
- Sexual Dysfunction in 10-15% of cases
- Similar to Luvox and Effexor in terms of this effect
- See Antidepressant Induced Sexual Dysfunction
-
Arrhythmia risk
- Prolonged QTc Interval and Torsades de Pointes risk
- Avoid in Prolonged QTc (e.g. congenital Prolonged QTc) or combined with other causes of Drug-Induced QTc Prolongation
- Monitor and correct for Electrolyte abnormalities (e.g. Hypokalemia, Hypomagnesemia) if risks
- See SSRI Overdose
- P450 Metabolism to di-desmethylcitalopram
- Overdose presentation (esp. ingestions >600 mg)
- Evaluation and Management
- See SSRI Overdose
- See Serotonin Syndrome
- See Unknown Ingestion
- Correct Electrolyte abnormalities (e.g. Hypokalemia, Hypomagnesemia)
- Monitoring
- Asymptomatic
- Monitor up to 12 hours if suspected ingestion >400 mg
- Symptomatic or QTc Prolongation
- Monitor until resolution of symptoms and QTc normalization
- Asymptomatic
- References
- Tomszewski (2021) Crit Dec Emerg Med 35(12): 32
- Avoid with MAO Inhibitors or Tryptophan
-
Cytochrome P450 2C19 Inhibitors (or poor 2C19 metabolizers)
- Arrhythmia risk
- Prolonged QTc Interval and Torsades de Pointes risk
- Avoid combining with other medication causes of Drug-Induced QTc Prolongation
- Most significant agents
- Agents that do not appear to have significant interactions
- Precautions
- Limit Citalopram to 20 mg daily in those on Omeprazole, Esomeprazole, Oral Contraceptives
- Consider Escitalopram (Lexapro) instead which appears safe to at least 20 mg daily with these agents
- Resources
- FDA Drug Safety Notice
- Arrhythmia risk
- (2023) Med Lett Drugs Ther 62(1592): 25-32
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 38-9
- Hamilton (2020) Tarascon Pocket Pharmacopoeia