Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Consult your doctor or pharmacist for advice specific to your medications.
80 mg of citalopram is exactly twice the daily maximum the FDA recommends for most adults, and four times the maximum for anyone over 60. A single accidental ingestion at 80 mg is usually mild and resolves within 12 hours. The reason this dose stands out: in 2011, the FDA issued a Drug Safety Communication warning that doses above 40 mg per day cause dose-dependent QT prolongation. Call Poison Control at 1-800-222-1222 (free, 24/7) if you have symptoms, are over 60, have liver disease, or take cimetidine. Call 911 if you faint, have seizures, or develop chest pain.
What follows: why 80 mg is specifically the FDA-flagged threshold, why a single accidental dose is different from chronic 80 mg per day, the 6 to 8 hour monitoring window, and who actually needs an ECG.
Why 80 mg of citalopram is the dose the FDA specifically flagged
Citalopram comes in 10, 20, and 40 mg tablets. There is no 80 mg tablet, so 80 mg always means two 40 mg pills, four 20 mg pills, or some combination that adds up to 80 mg. That math matters because the FDA prescribing information caps the standard adult dose at 40 mg per day, and 20 mg per day for several special groups.
The 2011 FDA Drug Safety Communication came from a thorough QT (TQT) study showing that citalopram causes a dose-dependent prolongation of the QT interval, the time it takes the heart to electrically reset between beats. The longer the QT, the higher the risk of a specific dangerous rhythm called Torsade de Pointes (TdP). The FDA's bottom line: doses above 40 mg per day were not more effective than 40 mg per day, and they raised cardiac risk without therapeutic benefit.
A March 2012 FDA clarification added a tighter cap (20 mg per day) for patients over 60, those with hepatic impairment, CYP2C19 poor metabolizers, and people taking cimetidine or other CYP2C19 inhibitors. For these groups, 80 mg is four times the safe daily maximum.
In short: 80 mg is the dose that crosses the FDA-flagged line for QT-related cardiac risk.
Acute single 80 mg vs chronic 80 mg per day
This is the part most articles miss. There is a real difference between taking 80 mg once by accident and taking 80 mg every day for weeks.
The FDA warnings target the chronic case. A patient on 80 mg per day for months reaches steady-state blood levels much higher than someone with one accidental 80 mg dose. A 2016 retrospective chart review in The Mental Health Clinician (N=73 VA adults) found that 4 of 6 cases of severe QT prolongation occurred in patients on chronic 60 mg per day. That is the FDA's actual concern.
A single accidental 80 mg dose still raises QT, but typically less dramatically and only transiently. A 2020 ToxIC Registry analysis in Clinical Toxicology (N=6,473 acute single-substance overdoses) found that acute citalopram overdose produced a mean QTc shift of +21.7 ms, with 25% of cases developing severe QT prolongation (adjusted odds ratio 2.2). That includes some genuine overdoses much larger than 80 mg.
For perspective on scale: a 2014 fatal case report in the Journal of Medical Toxicology involved a serum citalopram level of 7,300 ng/mL (therapeutic range 9 to 200 ng/mL). 80 mg single ingestion does not approach that territory.
A practical reassurance: the threshold where activated charcoal is even considered for citalopram overdose is around 600 mg per Friberg 2005. 80 mg is well below that mark.
What to do in the next hour
- Call Poison Control: 1-800-222-1222. Free, 24/7, confidential. They will ask your weight, current medications, and time of ingestion, then tell you whether you need an ECG, observation at home, or emergency room evaluation. Online alternative: webpoisoncontrol.org.
- Note the time you took the dose. QT prolongation from acute citalopram peaks around 7.8 hours after ingestion (Friberg 2005). The 6 to 8 hour window is when symptoms are most likely to show up.
- Do not take your next scheduled dose. MedlinePlus is explicit on missed doses: "if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule."
- Avoid alcohol, grapefruit juice, and other QT-prolonging drugs for at least 24 hours. Common QT-prolonging medications include some antibiotics (azithromycin, ciprofloxacin), antifungals (fluconazole), antipsychotics, and methadone.
- Stay with someone if possible. This is mostly precautionary, especially for the first 8 hours.
Call 911 instead of Poison Control if you faint, have a seizure, develop chest pain or fluttering in the chest, or have severe difficulty breathing.
Symptoms to watch for over the next 6 to 12 hours
The FDA citalopram label, Section 10 Overdosage, names the symptom set: "Seizures, which may be delayed, and altered mental status including coma" plus cardiac changes including QRS and QTc interval prolongation, wide-complex arrhythmias, and Torsade de Pointes. Serotonin syndrome is possible but mostly when other serotonergic drugs are co-ingested.
For a single accidental 80 mg dose, the most relevant signals are cardiac: racing heart, fluttering or skipped beats, dizziness on standing, fainting, chest discomfort. These can show up later than expected, and the 7.8-hour delayed peak is a real thing.
Neurological symptoms come next: drowsiness, confusion, tremor, jitteriness. Mild drowsiness is common and usually resolves overnight.
Gastrointestinal symptoms (nausea, vomiting) usually appear within the first 1 to 2 hours.
Serotonin syndrome is rare with single citalopram ingestion alone but matters if you take other serotonergic drugs (other SSRIs, SNRIs, MAOIs, tramadol, triptans, St John's wort). The pattern: fever, sweating, severe muscle stiffness or twitching, agitation, fast heartbeat.
Mild drowsiness or nausea that fades within 6 to 8 hours and never escalates is the typical 80 mg outcome. Anything cardiac (chest pain, fluttering, fainting), anything seizure-like, or any of the serotonin syndrome cluster warrants emergency care.
Who needs an ECG
The 2012 FDA clarification gives the practical answer. ECG monitoring after acute citalopram overdose is most important if any of the following apply:
- You are over 60 years old.
- You have hepatic impairment (liver disease, cirrhosis).
- You are a known CYP2C19 poor metabolizer (some patients learn this from pharmacogenetic testing).
- You take cimetidine or another CYP2C19 inhibitor.
- You take other QT-prolonging medications (azithromycin, ciprofloxacin, fluconazole, methadone, some antipsychotics).
- You have a history of arrhythmia, congenital long QT syndrome, heart failure, or recent heart attack.
- You have low potassium or magnesium (electrolyte abnormalities amplify QT risk).
If any of these apply to you, do not wait it out at home. Poison Control will likely refer you to an emergency department for ECG monitoring through the 6 to 8 hour QT peak window. The label sets the discontinuation threshold at QTc above 500 ms.
If none of these apply and you have no symptoms, Poison Control may clear you for home monitoring with a check-in plan.
Why escitalopram (Lexapro) is in a different category
A useful contrast for anyone confused about whether the same warning applies to Lexapro: the 2011 and 2012 FDA Drug Safety Communications applied to citalopram only. Escitalopram (Lexapro) is the S-enantiomer of citalopram, but the current escitalopram label does not carry the same dose-dependent QT prolongation warning at standard doses. If you accidentally took an extra 20 mg of Lexapro, the calculus is closer to our accidentally took double dose of Lexapro guide, not this one.
What QT prolongation actually means
Plain version: every heartbeat has an electrical reset phase. The QT interval is how long that reset takes. If it gets too long (most concerning above 500 ms), the heart can fall into a chaotic rhythm called Torsade de Pointes, which can cause fainting and, rarely, sudden cardiac arrest.
Citalopram lengthens the QT interval in a dose-dependent way. At 20 to 40 mg per day, the effect is small and clinically insignificant for most people. At 60 to 80 mg per day chronically, the effect is large enough that the FDA stopped recommending those doses. A single accidental 80 mg dose causes a transient prolongation that usually resolves as the drug clears.
That is why timing of monitoring matters. The peak QT effect from a single ingestion arrives several hours after the dose, not immediately. ECG done at hour 1 may look fine while hour 7 shows the change.
How Pillo helps you avoid this happening
The most common cause of a doubled citalopram dose is a forgotten morning dose taken on top of an evening dose, or a half-asleep "did I take it?" moment. A standard phone alarm rings and stops. A medication reminder app keeps the dose visible until you actually confirm it.
Pillo uses persistent alarms that will not stop until you respond and logs every dose you confirm. For SSRIs like citalopram where doubling can push you over the FDA-flagged threshold, that confirmation log is the difference between a clean dose and a 7-hour worry.
For more on the underlying behavior, see what to do when you cannot remember if you took your medication.
Frequently asked questions
Will 80 mg of citalopram cause permanent damage?
Almost never from a single accidental dose in someone without prior cardiac issues. The FDA's concern is dose-dependent QT prolongation that becomes clinically significant with chronic use above 40 mg per day. A one-time 80 mg ingestion typically causes a transient QT shift that resolves as the drug clears, and serum levels stay far below the territory seen in fatal massive overdoses (Kraai 2014 describes 7,300 ng/mL, far above what an 80 mg single dose produces). If you are over 60, have liver disease, or take CYP2C19-inhibiting drugs, the safety margin is smaller and ECG monitoring is wise.
Do I need to go to the ER if I feel fine?
Call Poison Control first. If you have none of the special-population risk factors (over 60, hepatic impairment, CYP2C19 poor metabolizer, cimetidine, other QT-prolonging drugs, prior arrhythmia, or electrolyte issues) and you have no symptoms, they may clear you for home monitoring. The 6 to 8 hour delayed QT peak is the reason they will likely want you to check in again later, even if you feel fine at hour 1.
What about 60 mg accidentally? Is that the same risk?
60 mg sits between the FDA's 40 mg recommended max and the 80 mg threshold this article addresses. The 60 mg case still exceeded the FDA's daily cap but with a smaller margin. Same plan: call Poison Control, note the ingestion time, watch the 6 to 8 hour window. The special-population checklist applies the same way. For the broader generic double-dose context, our companion article on accidentally took double dose of citalopram covers the 2x40 mg, 2x20 mg, and 2x10 mg scenarios.
How long does citalopram stay in your system?
The half-life is about 35 hours, so a single 80 mg dose takes roughly 5 to 7 days to fully clear. The QT-relevant peak is much earlier, around 7.8 hours post-ingestion. Most acute symptoms resolve within 12 hours.
Should I skip my next regular dose?
Yes. Per the FDA label and MedlinePlus, do not take a make-up dose. Resume your regular schedule the day after, unless your doctor or Poison Control tells you to wait longer.
Does Lexapro (escitalopram) have the same 80 mg risk?
No. The 2011 and 2012 FDA Drug Safety Communications addressed citalopram only. Escitalopram has its own dose recommendations and does not carry the same dose-dependent QT signal at standard doses per its current label. See our accidentally took double dose of Lexapro guide for the equivalent context.
Can I drink alcohol after taking 80 mg by accident?
No, not for at least 24 hours. Alcohol amplifies sedation, can worsen QT prolongation when combined with citalopram, and clouds your ability to notice cardiac symptoms.
Related guides
- Accidentally took double dose of citalopram (2x40 mg, 2x20 mg, 2x10 mg)
- Missed dose of citalopram
- Best time to take citalopram
- Accidentally took double dose of Lexapro
- Accidentally took double dose of sertraline
- What to do when you cannot remember if you took your medication
This article provides general information about citalopram and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor or pharmacist for advice specific to your medications. If you think you may have a medical emergency, call 911 or your local emergency number immediately.
Reviewed sources: FDA citalopram label (DailyMed), FDA accessdata Celexa label PDF (2024), FDA Drug Safety Communication August 2011, FDA Drug Safety Communication March 2012, MedlinePlus citalopram, Campleman 2020 QT prolongation overdose registry, Friberg 2005 PK-PD QT modelling, McClelland 2016 chronic dose QTc study, Kraai 2014 fatal overdose case, Poison Control.
Reviewed under our Medical Review Policy.
