Citalopram
An SSRI used for depression and panic disorder, known for its dose-related QT prolongation.
Drug card
- Class
- SSRI
- How it works
- Blocking serotonin reuptake, so serotonin stays longer in the synapse
- Used for
- Depression
- Panic disorder
- Known for
- Delayed ejaculation and other sexual problems
- QT prolongation and torsades de pointes
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does citalopram work?
Citalopram is a racemic mixture that selectively blocks the serotonin transporter; its S-enantiomer, escitalopram, does most of this work. It prolongs the QT interval in a dose-dependent way, which is why its label limits use in people with heart rhythm risks.
Like other selective serotonin reuptake inhibitors: SSRIs block the serotonin transporter (SERT) on presynaptic nerve endings, so released serotonin is cleared more slowly and acts longer on its receptors. The block is immediate but mood lifts only after weeks, so slower receptor adaptations are thought to matter; the exact mechanism is unknown. Unlike tricyclics, they barely affect norepinephrine reuptake or muscarinic, histamine and α1 receptors.
Uses
What is citalopram used for?
- Depression
- Panic disorder
Side effects
Side effects of citalopram
- Delayed ejaculation and other sexual problemsKnown for
- QT prolongation and torsades de pointesKnown forSerious
- Nausea
- Dry mouth
- Heavy sweating
- Drowsiness or trouble sleeping
- Palpitations
- Serotonin syndromeSerious
- Suicidal thoughts in children and young adultsSerious
- Low sodium (hyponatremia)Serious
- Abnormal bleedingSerious
- Mania in people with bipolar disorderSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Avoid in congenital long QT, slow heart rate, recent heart attack or uncompensated heart failure, and with other QT-prolonging drugs.
- Correct low potassium or magnesium before use, and stop it if the QTc stays above 500 ms.
- Contraindicated with MAOIs (leave 14 days either way) and with pimozide.
Good to know: Its label carries a specific warning on dose-dependent QT prolongation and torsades de pointes; escitalopram is its active S-enantiomer.
Remember it
A way to remember it
SSRI
- S
- Sexual problems
- S
- Serotonin syndrome
- R
- Reduced sodium (hyponatremia)
- I
- Increased bleeding risk
Written for biofideX
Its class
Selective serotonin reuptake inhibitors
Other selective serotonin reuptake inhibitors with a card:
Easily mixed up with serotonin-norepinephrine reuptake inhibitors and tricyclic antidepressants.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Depression, anxiety and sleep
Citalopram is one of 15 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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