Celexa dosage, forms, and strengths

Celexa is a brand-name prescription drug (generic name: citalopram) used to treat major depressive disorder (depression). Citalopram hydrobromide, the active ingredient in Celexa, belongs to a class of drugs called selective serotonin reuptake inhibitors (SSRIs), which also include antidepressants such as Prozac (fluoxetine), Zoloft (sertraline), and Lexapro (escitalopram). Serotonin is a chemical that passes signals between nerves in the brain. By increasing the amount of serotonin at nerve junctions, citalopram improves brain functioning to better manage mood. To improve depression symptoms, Celexa tablets are taken every day for several months.

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Celexa forms and strengths

Celexa is sold as an oral tablet that is available in three different strengths. Generic citalopram is also available as an oral solution for people who have difficulty swallowing tablets.

• Tablets: 10 milligrams (mg), 20 mg, 40 mg

Celexa dosage for adults

The Food and Drug Administration (FDA) has approved Celexa only for the treatment of major depressive disorder. Some doctors, however, may prescribe Celexa off-label to treat obsessive-compulsive disorder. Other off-label uses of Celexa include the treatment of alcohol use disorder, generalized anxiety disorder, panic disorder (characterized by recurring panic attacks), premenstrual dysphoric disorder, postmenopausal flushing, and depression in people with coronary arteriosclerosis. For most of these conditions, doses are about the same as the recommended adult dose for depression. However, the exact dosage will be determined by a healthcare provider. 

Celexa dosage for children

Celexa is not approved for use in children younger than 18 years old. However, Celexa is routinely prescribed off-label to treat major depressive disorder, social anxiety disorder, and obsessive-compulsive disorder in children and adolescents.

• Off-label dosage for major depressive disorder in children 7–11: 20–40 mg once per day with a starting dose of 10 mg once per day

• Off-label dosage for major depressive disorder in children 12–17: 20–40 once per day with a starting dose of 20 mg once per day

• Off-label dosage for social anxiety disorder in children 8–17: 10–40 mg once per day with a starting dose of 5–10 mg once per day

• Off-label dosage for obsessive-compulsive disorder in children 6–17: 10–40 mg once per day with a starting dose of 10 mg once per day

Celexa dosage restrictions

Celexa may not be appropriate for every person. In particular, anyone with a history of allergic reactions to citalopram will not be given the drug. Some medical conditions, though, may require restrictions.

Celexa can cause potentially fatal changes in the heart’s rhythm, so people with congenital long QT syndrome should avoid taking Celexa. People with other heart problems, such as congestive heart failure, may take Celexa at normal doses, but frequent electrocardiograms (ECGs) may be needed. Because of the risk to the heart, people with low potassium (hypokalemia) or low magnesium (hypomagnesemia) due to a concomitant medical condition will need these conditions resolved before taking Celexa.

Citalopram and other SSRIs do not raise blood pressure as other antidepressants do, so no dose adjustments are required for people with high blood pressure. People with kidney disease (renal impairment) or who are on dialysis can also take the standard dosage. 

However, the maximum dosage will be decreased to 20 mg a day in people older than 60. People with liver disease (hepatic impairment) or who are CYP2C19 poor metabolizers—that is, their bodies break down citalopram more slowly than others—will also be given lower maximum doses of 20 mg a day.

How to take Celexa

Celexa tablets are taken once daily with or without food. Continue taking Celexa even if it does not seem to help at first. Celexa may need to be taken a month or more before having an effect. 

• Take this medicine as directed. The dose may sometimes need to be changed.

• Read the medication guide that comes with a Celexa prescription. Ask the pharmacist for a copy if it’s missing.

• Store the medicine in a tightly closed container at room temperature (59°F–86°F), away from heat, moisture, and direct light.

Celexa dosage FAQs

How long does it take Celexa to work?

Celexa will start improving depression symptoms in one to four weeks. A full response may take longer—up to eight or 12 weeks. As a general rule, major depressive episodes often require several months of daily medical therapy to fully resolve. If the drug is discontinued too early, there is a risk that depression will recur.

How long does Celexa stay in your system?

With a half-life of 24–48 hours (35 hours on average), a single dose of Celexa falls to undetectable levels in the body in about one week. This may take longer if Celexa has been taken for a prolonged period or if a person breaks down citalopram slowly. 

What happens if I miss a dose of Celexa?

Take a missed dose as soon as it’s remembered. If it is almost time for the next dose, skip the missed dose and take the next dose on schedule. Do not take extra medicine to make up for a missed dose.

How long can you take Celexa?

As a general rule, it takes six months of antidepressant therapy to fully resolve a major depressive episode, but treatment could go on for as long as nine months to ensure depression symptoms do not return. After that, Celexa is usually discontinued. However, people with recurrent depression may need longer or indefinite drug treatment. Fortunately, there is no evidence that Celexa is harmful in the long term.  

How do I stop taking Celexa?

When Celexa or other antidepressants are taken continuously for a month or more, stopping the medication can cause withdrawal symptoms. Called discontinuation syndrome, withdrawal affects anywhere from 27% to 86% of people taking antidepressants. Almost half experience severe symptoms. The most common antidepressant withdrawal symptoms include: 

• Nausea 

• Headaches 

• Lightheadedness 

• Unusual sensations

• Sleeplessness

• Chills

• Muscle aches

• Dizziness

• Restlessness

• Tremors

• Depressed mood

• Anxiety

• Impaired coordination

• Irritability

• Impulsivity  

For Celexa, withdrawal symptoms typically begin three to five days after stopping the drug and persist for one to two weeks, though symptoms may last for several weeks. Some people have experienced antidepressant withdrawal for more than a year. To prevent discontinuation syndrome, the dosage of Celexa is gradually tapered, or decreased, over several weeks. Even then, nearly 60% of people will experience withdrawal symptoms after discontinuing an antidepressant. 

For several reasons, Celexa may need to be discontinued early. If Celexa can no longer be taken, another SSRI may be prescribed. If that’s not ideal, alternative antidepressant medications include tricyclic antidepressants, SNRIs (serotonin and norepinephrine reuptake inhibitors), monoamine oxidase inhibitors (MAO inhibitors), or atypical antidepressants.

What is the maximum dosage for Celexa?

The maximum dose for Celexa is 40 mg per day. However, doctors may prescribe as much as 60 mg daily off-label to treat obsessive-compulsive disorder. Still, the FDA warns of a risk of heart rhythm problems when doses greater than 40 mg per day are taken. 

Can you overdose on Celexa?

A Celexa overdose is rarely fatal, but anyone who has taken an overdose should receive emergency medical care. Celexa can interrupt the heartbeat and, in rare cases, could damage the kidneys. The symptoms of citalopram overdose include nausea, vomiting, dizziness, tremor, sleepiness, sweating, and a fast heartbeat (tachycardia). Extreme overdoses can significantly change the heart’s rhythm, damage muscles (rhabdomyolysis), and cause hyperventilation, confusion, seizures, and coma. 

What interacts with Celexa?

Celexa has some drug interactions that may require monitoring, treatment modification, or avoiding certain combinations altogether. Do not take Celexa until you talk to your doctor about whether you take the following medications:

• Monoamine oxidase inhibitors (MAOIs) 

• Other antidepressants 

• Migraine medications

• Antipsychotic medications

• Bipolar disorder medications

• Anxiety drugs

• Amphetamines

• Opioid pain relievers

• Seizure medications

• Cough medicines

• Anti-nausea drugs 

• Parkinson’s disease medications

• Certain supplements or over-the-counter medications

Other drugs that may interact with Celexa include sedatives, benzodiazepines, certain anti-diarrheal medications, certain antibiotics, certain antifungals, arrhythmia drugs, NSAIDs, and blood thinners.

What happens when you mix Celexa and alcohol?

Celexa can cause drowsiness and motor impairment, so combining Celexa and alcohol can worsen these adverse effects. People taking antidepressants are strongly urged not to drink alcohol. Drinking often worsens the symptoms of depression, so alcohol will interfere with the therapeutic effects of taking Celexa.

Is it safe to take Celexa during pregnancy?

Celexa and any other SSRI antidepressants are risky when taken during pregnancy, particularly in the third trimester. Fetuses exposed to SSRIs are at an increased risk for lung problems (persistent pulmonary hypertension of the newborn) that could prove fatal to the baby. 

On the other hand, pregnant women who discontinue antidepressant treatment are vulnerable to a relapse of the condition. Prospective mothers should discuss the risks and benefits of taking Celexa while pregnant with a healthcare professional. Celexa doses will probably not be modified for pregnant women.

Nursing mothers should consider discontinuing Celexa or finding an alternative to breastfeeding. Citalopram does pass into breast milk and can cause sleepiness, decreased feeding, and weight loss in a nursing infant. Again, the best option is to seek medical advice from a doctor or healthcare professional.

Related resources:

• Antidepressant discontinuation syndrome

• A review of the management of antidepressant discontinuation syndrome

• A systematic review into the incidence, severity, and duration of antidepressant withdrawal effects: Are guidelines evidence-based?

• Celexa

• Celexa medication guide

• Celexa prescribing information

• Citalopram

• Citalopram (Celexa)

• Citalopram compound information

• FDA drug safety communication: Abnormal heart rhythms associated with high doses of Celexa (citalopram)

• Practical guideline for the treatment of patients with major depressive disorder

• Protracted withdrawal syndrome after stopping antidepressants: a descriptive quantitative analysis of consumer narratives from a large internet forum

• Selective serotonin reuptake inhibitor discontinuation syndrome: Understanding, recognition, and management for psychologists

• Steps following attainment of remission: Discontinuation of antidepressant therapy