This article is for informational purposes only and does not constitute medical advice. Always consult your doctor or pharmacist before making any changes to your medication routine.
If you forgot to take your citalopram, take it as soon as you remember. If it's almost time for your next dose, skip the missed one and take tomorrow's dose at your usual time. Don't take a double dose. One missed dose of citalopram won't erase weeks of treatment because the drug leaves your system slowly.
Why a missed celexa dose matters
Citalopram (sold as Celexa) is an SSRI antidepressant that works by increasing serotonin availability in your brain. Like other SSRIs, it builds up in your system over time. It's not like a pain reliever you feel wearing off after a few hours.
Citalopram has a half-life of about 35 hours. After one missed dose, roughly half the drug is still circulating in your body a day and a half later. So a single skipped dose causes a dip, not a crash.
The real risk comes from missing multiple doses. As citalopram levels drop, your brain starts adjusting to less serotonin. This can trigger what doctors call antidepressant discontinuation syndrome. Symptoms usually show up 2 to 4 days after stopping and can include:
- Dizziness or lightheadedness
- Nausea and headaches
- Irritability, anxiety, or mood swings
- Trouble sleeping
- "Brain zaps" -- brief electric shock sensations in your head
- Flu-like symptoms
Brain zaps catch people off guard. They feel like a quick jolt or buzz inside your skull, often triggered by eye movement. They're not dangerous, but they're alarming if you don't know what's happening.
About half of people on antidepressants have trouble staying consistent with their medication. So if you've missed a dose, you're far from alone. But understanding why consistency matters can help you stay on track. If you're juggling several prescriptions, our guide on managing multiple medications has practical strategies.
What to do when you forgot to take citalopram
Here's a simple guide based on FDA-approved prescribing information:
| When you remember | What to do |
|---|---|
| Same day, a few hours late | Take it now. Go back to your regular schedule tomorrow. |
| Same day, evening (if you usually take it in the morning) | Take it. Citalopram can be taken morning or evening. |
| Next day, close to your next scheduled dose | Skip the missed dose. Take your regular dose at the normal time. |
| You've missed 2+ days | Contact your doctor before restarting. They may advise resuming at your regular dose or adjusting the restart. Don't try to make up for missed days. |
A few things to keep in mind:
- Don't double up. Taking two doses of citalopram at once won't "catch you up." It just increases side effects like nausea, drowsiness, and dizziness.
- No food requirement. Citalopram can be taken with or without food, so grab it whenever you remember.
- Morning or evening, either works. The FDA label says citalopram is taken once daily. Pick whichever time you're least likely to forget.
Citalopram vs. Lexapro: what happens if you miss a dose?
You might have heard that citalopram and Lexapro (escitalopram) are closely related. That's true. Citalopram is the racemic mixture of two mirror-image molecules, while escitalopram is just the active one (the S-enantiomer). Lexapro is essentially the refined version of citalopram.
For missed dose purposes, the rules are almost identical. Both have similar half-lives (citalopram ~35 hours, escitalopram ~27-32 hours), and both follow the same guidance: take it when you remember, skip if near your next dose, never double up.
One key difference: citalopram carries an FDA warning about QT prolongation at higher doses that escitalopram does not share to the same degree. That makes it extra important not to take two doses of citalopram at once. More on the heart rhythm issue below.
If you're comparing the two medications, see our guide on missed dose of Lexapro for details specific to escitalopram.
How citalopram compares to other antidepressants
Different antidepressants leave your body at different speeds, which affects how quickly you notice a missed dose. Here's a comparison of commonly prescribed options:
| Medication | Brand name | Type | Half-life | Missed dose window | Discontinuation risk |
|---|---|---|---|---|---|
| Fluoxetine | Prozac | SSRI | 2-4 days (active metabolite: 4-16 days) | Very forgiving | Low |
| Citalopram | Celexa | SSRI | ~35 hours | Moderate | Moderate |
| Escitalopram | Lexapro | SSRI | ~27-32 hours | Moderate | Moderate |
| Sertraline | Zoloft | SSRI | ~26 hours | Moderate | Moderate |
| Duloxetine | Cymbalta | SNRI | ~12 hours | Short | Higher |
Fluoxetine is the most forgiving to miss because its active metabolite (norfluoxetine) lingers in your body for days to weeks. Citalopram sits in the middle. You have more of a buffer than with duloxetine (an SNRI, not an SSRI, but included for comparison since it's commonly prescribed alongside SSRIs), but less room for error than with fluoxetine.
For more on the others, see our guides on missed dose of sertraline, missed dose of fluoxetine, and missed dose of duloxetine. We also have a broader guide on missed antidepressant doses if you want an overview.
When to call your doctor
One missed dose of citalopram usually doesn't require a phone call. But reach out to your doctor or pharmacist if:
- You've missed two or more days in a row and you're experiencing brain zaps, dizziness, nausea, or mood swings. Your doctor may want to guide you on how to restart safely.
- Discontinuation symptoms are severe or lasting more than a few days after resuming your medication.
- You keep forgetting. If missing doses is becoming a pattern, your doctor needs to know. They might adjust your timing, simplify your regimen, or discuss whether citalopram is still the right fit.
- You want to stop citalopram. Never quit an SSRI cold turkey. Your doctor will create a gradual tapering plan over weeks or months to minimize withdrawal symptoms. Our guide on stopping medications safely covers what to expect.
- You notice heart-related symptoms. Citalopram can cause dose-dependent QT prolongation, a change in your heart's electrical activity. If you experience a racing heartbeat, fainting, irregular heartbeat, or severe dizziness after a dose change, seek medical attention right away. This is especially important if you accidentally doubled a dose.
If you experience thoughts of self-harm or suicide, seek immediate help. Call 988 (Suicide & Crisis Lifeline) or go to your nearest emergency room. The FDA requires a black box warning that antidepressants may increase suicidal thoughts in young adults under 25 during the first weeks of treatment or after dose changes.
How to stay consistent with citalopram
Citalopram is once a day, with no food restrictions, and flexible on morning vs. evening timing. That's about as simple as a medication schedule gets.
The tricky part: once-a-day medications are easy to forget because there's only one window to remember. If you miss it, that's it for the day.
Start by anchoring citalopram to something you already do. If you take it in the morning, keep it next to your coffee maker or toothbrush. If you take it at night, pair it with your bedtime routine. Habit stacking works better than willpower.
If anchoring alone isn't enough, Pillo uses persistent alarms that keep going until you respond to them. It also logs your medication history, so on days when you can't remember if you took your medication, you can check instead of guessing. With an SSRI like citalopram, that matters. Doubling a dose carries real risks, and skipping one isn't great either.
FAQ
What happens if you miss citalopram for one day?
Usually nothing noticeable. Citalopram has a half-life of about 35 hours, meaning roughly half the drug is still in your system a day and a half later. Most people won't feel any different after one missed dose. If you're sensitive to serotonin changes, you might notice mild dizziness or mood shifts, but this is uncommon from a single skip. Take your next dose at your regular time.
Can I take citalopram late if I forgot my morning dose?
Yes. Citalopram can be taken at any time of day with or without food. If you normally take it in the morning and forgot, take it when you remember, even if it's afternoon or evening. If it's already the next day and you're close to your scheduled dose, skip the missed one. Don't take two.
Is citalopram the same as Lexapro?
Not exactly. Citalopram (Celexa) is the racemic version that contains two mirror-image molecules. Lexapro (escitalopram) contains only the active S-enantiomer. They work similarly, but escitalopram is often prescribed at lower doses and doesn't carry the same level of QT prolongation risk. Missed dose rules are the same for both. See our Lexapro missed dose guide for more.
What are the signs of citalopram withdrawal?
Stopping citalopram abruptly can cause discontinuation syndrome: dizziness, nausea, headaches, irritability, brain zaps (brief electric shock sensations), trouble sleeping, and flu-like symptoms. These typically start 2 to 4 days after stopping and can last 1 to 2 weeks, though some cases may persist longer. Your doctor should create a gradual tapering schedule if you want to stop. Never stop citalopram on your own.
Why does citalopram have a QT prolongation warning?
In 2011, the FDA warned that citalopram can cause dose-dependent changes in the heart's electrical activity (QT interval prolongation). The maximum recommended dose is 40 mg per day, and 20 mg for adults over 60 or those with liver problems. This is why you should never double up on a missed dose. If you experience fainting, irregular heartbeat, or severe dizziness, seek medical help immediately.
This article provides general information about citalopram and is not a substitute for professional medical advice. Always consult your doctor or pharmacist before making changes to your medication schedule. If you experience thoughts of self-harm, suicidal ideation, or severe discontinuation symptoms, seek medical attention immediately. Call 988 (Suicide & Crisis Lifeline) if you or someone you know needs help.
