Citalopam

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Citalopam

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Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Citalopam

Quick Facts

  • Drug Class: Selective Serotonin Reuptake Inhibitor (SSRI)
  • Primary Indication (FDA-Approved): Treatment of major depressive disorder (MDD) in adults
  • Administration: Oral tablet or solution, typically once daily

What is Citalopram?

Citalopram, marketed under brand names such as Celexa, is a prescription antidepressant medication indicated for the treatment of major depressive disorder (MDD) in adults. It belongs to a group of drugs known as Selective Serotonin Reuptake Inhibitors (SSRIs).

Mechanism of Action

Citalopram is considered a highly selective SSRI. Its primary function is to increase the concentration of the neurotransmitter serotonin in the brain's central nervous system (CNS). Serotonin plays a vital role in regulating mood, anxiety, and behavior.

Normally, serotonin is released by a nerve cell (neuron) into the space between neurons (the synaptic cleft) and is then reabsorbed by the releasing cell via the serotonin transporter (SERT). Citalopram works by blocking the reuptake of serotonin into the presynaptic neuron, a process called inhibition of serotonin reuptake. This action leads to higher levels of serotonin remaining in the synaptic cleft, thereby enhancing serotonergic activity and communication between brain cells to help alleviate depressive symptoms.

It is important to note that while the biochemical effect occurs quickly, the full therapeutic benefit of citalopram may take several weeks—typically one to four weeks—to become apparent. Citalopram is also listed on the World Health Organization's model list of essential medicines for treating depressive disorders.

Regulatory References

  1. Citalopram - StatPearls (NIH)
  2. WHO Model List of Essential Medicines

What side effects are possible with Citalopam?

Possible Side Effects and Safety Information

This section summarizes the officially documented adverse reactions and safety information for citalopam, based on authoritative government regulatory sources. It is not a guide for use or dosage.

Serious and Clinically Significant Adverse Reactions

Official labeling highlights several serious risks. These include the potential for QT interval prolongation, a dose-dependent effect that can lead to a fatal heart rhythm called Torsade de Pointes. This risk is the basis for mandated maximum daily dose restrictions. Patients with pre-existing heart rhythm issues are contraindicated from use.

Other serious documented risks include the potential for Serotonin Syndrome, a potentially life-threatening condition, and the emergence or worsening of suicidal thinking and behavior, particularly in children, adolescents, and young adults. The drug is also associated with a documented risk of Hyponatremia (low sodium levels in the blood) and increased risk of bleeding or hemorrhage.

Frequency-Classified Adverse Reactions

Adverse reactions are classified by frequency as reported in regulatory documents:

  • Very Common (Affecting 1 in 10 or more people): Headache, Nausea, Dry mouth, Increased sweating (hyperhidrosis), Somnolence (drowsiness), Insomnia.
  • Common (Affecting less than 1 in 10 people): Decreased appetite, Agitation, Tremor, Dizziness, Diarrhoea, Vomiting, Constipation, Weight decrease.

Population-Specific Safety Considerations

Lower maximum daily doses are mandated for geriatric patients (the elderly) and those with hepatic impairment (liver issues) due to reduced drug clearance and increased risk of adverse effects, including QT prolongation.

Upon stopping the medicine, patients may experience discontinuation reactions (withdrawal-like symptoms), which are officially documented and require gradual dosage reduction to minimize.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose of Citalopram is primarily defined by the risk of serious cardiac events and neurological symptoms. The most significant life-threatening presentation is a dose-dependent prolongation of the heart’s electrical activity (QT interval prolongation), which can lead to an abnormal heart rhythm called Torsade de Pointes and potentially sudden death, as observed in postmarketing reports.

Documented Overdose Symptoms

The documented clinical manifestations of overdose include seizures and the aforementioned cardiac abnormalities. Individuals at higher risk for severe cardiac toxicity include those with pre-existing heart conditions, low blood levels of potassium (hypokalemia) or magnesium (hypomagnesemia), or those over 60 years of age.

Emergency Action

Urgent medical attention is required immediately if you experience any signs or symptoms of an abnormal heart rate or rhythm while taking Citalopram, such as: irregular heartbeat, shortness of breath, dizziness, or fainting. You must also seek immediate care for the onset of seizures.

Electrolyte imbalances, such as low potassium or magnesium, should be corrected before starting Citalopram, as these increase the risk of QTc prolongation and arrhythmia. Regulatory bodies advise against prescribing doses greater than 40 mg per day for most patients due to the increased cardiac risk.

Therapeutic Uses of Citalopam

What Citalopram Treats: Main Uses and Benefits

Citalopram is an antidepressant primarily used to manage symptoms associated with Major Depressive Disorder (MDD). It is also applied across domains where additional symptomatic support is needed, including conditions characterized by heightened anxiety such as Panic Disorder, Obsessive-Compulsive Disorder (OCD), and significant Social Anxiety.

The medication helps address symptom clusters that may become intense or disruptive, focusing on manifestations like persistent depressed mood, loss of interest (anhedonia), and recurrent panic episodes. Applied in clinical settings that involve acute or disruptive symptom patterns, it may assist with maintaining functional stability during difficult episodes.

Quick Fact: Support for Symptomatic Discomfort

Citalopram is often used to address the combined physical and cognitive manifestations—such as chronic fatigue, sleep disturbances, and impaired concentration—that may accompany core mood and anxiety disorders. This may contribute to improved comfort during periods of heightened symptoms.

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Citalopram eligibility is defined by official regulatory bodies through specific constraints on patient populations. The medicine is contraindicated and must not be used in individuals with known hypersensitivity to the drug or any of its components. Absolute prohibitions also apply to patients taking, or recently having discontinued (within 14 days), a Monoamine Oxidase Inhibitor (MAOI), including linezolid. Co-administration with the drug pimozide is also strictly contraindicated.

Regulatory labeling establishes eligibility restrictions for several groups:

  • Pediatric Use: Citalopram is not approved for use in pediatric patients under 18 years of age, as safety and efficacy have not been established.
  • Restricted Dose: For older adults (over 60 years) and patients with hepatic impairment, the maximum recommended daily dose is restricted to 20 mg.
  • Comorbidity Restrictions: Use is not recommended in patients with specific cardiac conditions like congenital long QT syndrome or uncompensated heart failure, or for those with uncorrected hypokalemia or hypomagnesemia.
  • Pregnancy and Lactation: Caution is advised for use during pregnancy and while lactating.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documents define the interaction profile of citalopam based primarily on two major risks: the additive effect on serotonin and the risk of QTc prolongation (an electrical change in the heart's rhythm).

Contraindicated Combinations

Citalopram is contraindicated (must not be combined) with Monoamine Oxidase Inhibitors (MAOIs), including linezolid and intravenous methylene blue, due to the high risk of developing serotonin syndrome. A washout period of at least 14 days is required when switching between citalopram and an MAOI. Co-administration with the antipsychotic Pimozide is also contraindicated because of the compounded risk of QTc prolongation.

Pharmacodynamic and Pharmacokinetic Interactions

Interaction Type Interacting Product Categories Regulatory Requirement
Serotonin Increase Other serotonergic drugs (e.g., triptans, some opioids, other SSRIs, St. John’s wort) Requires close patient observation due to the risk of serotonin syndrome.
QTc Prolongation Drugs known to prolong the QTc interval (e.g., certain antiarrhythmics, antipsychotics, antibiotics) Avoid combination; use only if benefits outweigh risks, with monitoring.
Increased Bleeding Anticoagulants (e.g., warfarin) and antiplatelet agents (e.g., aspirin, NSAIDs) Requires caution and monitoring for bleeding risk.
Drug Exposure Increase CYP2C19 Inhibitors (e.g., cimetidine, omeprazole) Dose of citalopram must not exceed 20 mg/day.

This dose restriction of 20 mg/day also applies to patients who are known poor CYP2C19 metabolizers, or are over 60 years of age, or have reduced liver function, as these factors also lead to increased citalopram exposure.

Mechanism of Action

Selective Inhibition of Serotonin Transport

Citalopram acts as a highly specific inhibitor of the Serotonin Transporter (SERT), the protein responsible for reabsorbing serotonin ( 5-HT) from the synaptic space. This blockade immediately increases the concentration and duration of 5-HT available to activate postsynaptic receptors in the Central Nervous System, fundamentally altering neurotransmission dynamics.


Neuroplasticity Cascade and Delayed Mechanistic Consequence

The sustained potentiation of 5-HT signaling initiates a long-term molecular cascade that is necessary for the drug’s final mechanistic consequence. This process involves the downregulation of pre-synaptic autoreceptors and the elevation of Brain-Derived Neurotrophic Factor (BDNF) expression, which drives the structural and functional re-organization of neuronal circuits. This molecular change is a consequence which dictates the temporal sequence required for the physiological change.


Accessory Ion Channel Modulation

In addition to its primary mechanism, Citalopram also engages in the accessory blockade of specific potassium ( K^+) ion channels, including the hERG channel in the heart and Kv2.2 channels in cortical neurons. This off-target interaction alters the electrical timing of cellular repolarization, resulting in the modulation of neuronal excitability.

Dosage and Administration Information

How to Use Citalopram: Administration Guidelines

Citalopram is administered via the oral route, available as both tablets and an oral solution. The medicine is taken once daily and may be administered at any time of day, with or without food. Tablets should be swallowed whole, and the oral solution requires careful measurement using a calibrated device to ensure proper dosage.

Standard Adult Dosing and Limits

The typical regimen begins with a starting dose of 20 mg once daily. The standard maintenance dose range for adults generally falls between 20 mg and 40 mg. The maximum recommended dose for the general adult population is 40 mg per day.

Population Group Maximum Daily Dose Clinical Specification
Older Adults (over 60/65 years) 20 mg Dose reduction is specified
Hepatic Impairment 20 mg Dose reduction is specified

Course and Procedural Use

Prescribing guidelines dictate that dosage increases, if required, should only be implemented after the previous dose has been maintained for at least one week. For acute treatment, therapy is often continued for 6 months or longer to help prevent the recurrence of symptoms. The protocol for concluding treatment mandates a gradual dose reduction (tapering) over a period of at least 1 to 2 weeks to adhere to procedural standards for discontinuation.

Recent Clinical Evidence

Evidence for Use in Major Depressive Disorder (MDD)

Research examining Citalopam for Major Depressive Disorder was evaluated in extensive study types, including numerous short-term, randomized controlled trials (RCTs) and large-scale effectiveness studies. These studies primarily focused on measuring changes in depressive symptom scores using standardized scales and evaluating the rates of treatment response or remission. Studies conducted during periods of increased symptom activity report patterns of symptom score reduction when compared to placebo in controlled settings.

What remains unclear is that findings were mixed across studies regarding the specific rate at which participants achieved full remission. Consistency in this specific outcome has been noted as a research gap across some meta-analyses. Furthermore, the generalizability of data from highly controlled trials to routine clinical practice remains an area of research limitation.


Evidence for Use in Anxiety and Related Disorders

This area outlines the research structure for the secondary conditions where Citalopam was evaluated in trials: Panic Disorder, Obsessive-Compulsive Disorder (OCD), and Social Anxiety Disorder (SAD).

Research Structure for Panic Disorder

Research for Panic Disorder includes controlled trials and longer-term continuation studies. Research examined the change in the frequency of panic attacks and the measurement of overall panic symptoms and severity over defined time intervals. Long-term studies monitored participant status and outcomes over follow-up periods extending up to one year.

Research Structure for OCD and Social Anxiety

Research exploring Citalopam for OCD included placebo-controlled studies and open-label trials which monitored outcomes related to obsessive-compulsive symptoms. Findings describe patterns observed over trial periods of up to four months, with some evidence derived from open-label designs in patients who had not responded to prior treatments. Research for Social Anxiety Disorder (SAD) primarily utilized smaller, open-label pilot studies and systematic reviews. The evidence base for this condition is limited by its reliance on pilot designs and is less developed compared to the evidence base for MDD.


Long-Term Studies and Special Populations

Studies have explored Citalopam in maintenance protocols that track participant status over extended periods and assessed recurrence/relapse prevention over periods that may extend up to one year or more. Data for long-term outcomes are not fully established for all indications. Research has also explored outcomes for older adults and patient cohorts defined by comorbid conditions, but evidence for groups like children and adolescents may be limited compared to adults.


What Is Still Uncertain About Citalopam Research

One area of uncertainty relates to the consistency of remission rates reported across different studies for MDD. Furthermore, the generalizability of results from strictly controlled research settings to patients in routine clinical care remains a research limitation. The overall body of research provides context but not individual predictions. Findings describe group patterns, and research does not determine whether an individual will respond similarly. Comparative evidence against all other available treatment options is lacking in some areas.

Key Studies & References

  1. Citalopram - NIH StatPearls
  2. Citalopram Oral (MedlinePlus Drug Information)
  3. Citalopram - DrugBank Online (DB00420)

Frequently Asked Questions (FAQ)

Common questions about Citalopam (FAQ)

Q: How long does it typically take for Citalopam to start working?

A: The chemical effect on neurotransmitters happens quickly after treatment begins. However, official information indicates that the full therapeutic benefit for major depressive disorder is often delayed and may take several weeks—typically between one and four weeks—to fully appear in clinical settings.

Q: How long will I need to take Citalopam?

A: The duration of use is subject to clinical evaluation. Regulatory documents describe that for the acute treatment of major depressive disorder, therapy is often continued for six months or longer to help prevent symptoms from returning. The total length of treatment is subject to clinical evaluation based on the individual's needs.

Q: Is Citalopam used during pregnancy?

A: Regulatory documents describe the need for caution when the drug is considered for use during pregnancy. Official information indicates that the potential benefits must be carefully evaluated against any potential risks to the fetus. Citalopam is also known to be excreted into breast milk.

Q: Can Citalopam affect my heart rhythm?

A: Yes, Citalopam is officially associated with a dose-dependent risk of QT interval prolongation, which is a change in the electrical timing of the heart's rhythm. This risk is the reason regulatory agencies mandate restrictions on the maximum daily dose that can be administered.

Q: What is the purpose of the black box warning associated with Citalopam?

A: The black box warning is the most serious advisory from the FDA. It highlights the documented risk of the emergence or worsening of suicidal thinking and behavior, especially in children, adolescents, and young adults during the initial treatment or when the dose is adjusted.

Q: Does Citalopam cause weight gain?

A: Changes in weight or appetite can occur. Official adverse event listings include weight decrease and decreased appetite as common side effects. However, some clinical studies have also noted minimal weight gain patterns in long-term use.

Q: Is Citalopam a controlled substance?

A: No, Citalopam is a prescription medication but is not classified as a controlled substance by the U.S. Drug Enforcement Administration (DEA) schedule.

Q: What happens if I stop taking Citalopam suddenly?

A: Regulatory protocol describes the need for a gradual dose reduction (tapering) over at least one to two weeks to adhere to procedural standards for discontinuation. Abrupt cessation can lead to officially documented discontinuation symptoms, which are withdrawal-like effects that may be serious.

Q: Are there any specific foods or drinks I should avoid while on Citalopam?

A: Official regulatory labeling states that Citalopam may be taken with or without food, and no specific foods are restricted. Interactions with other drugs, supplements, and alcohol are addressed in regulatory labeling.

Q: Does Citalopam affect sex drive?

A: Yes, Citalopam is officially associated with sexual dysfunction. Documented effects in regulatory information include a decreased sex drive (libido), and issues related to delayed or absent orgasm or ejaculation.

Q: Can Citalopam cause mood swings?

A: While the term 'mood swings' is not explicitly listed, the medication is officially associated with the risk of activating mania or hypomania. These conditions involve periods of abnormally elevated or irritable mood, and this risk is listed in regulatory documents.

Q: Is it common to feel worse when first starting Citalopam?

A: Official documentation notes that improvement may not occur immediately, often not for the first few weeks of treatment. Regulatory documents note that close observation for clinical worsening or unusual changes in behavior, such as agitation or intensified anxiety, is part of the initial treatment protocol.

Q: Can Citalopam make anxiety worse initially?

A: Regulatory documents describe a risk of experiencing paradoxical anxiety or an initial intensification of anxiety symptoms, especially at the start of treatment for panic disorder. This reaction typically subsides within the first two weeks.

Q: Can Citalopam affect memory or concentration?

A: Official labeling states that Citalopam may interfere with cognitive and motor performance. Additionally, difficulty concentrating or memory impairment can be a symptom of a serious, though uncommon, side effect called Hyponatremia (low sodium levels in the blood).

Q: Is there a link between Citalopam and changes in appetite?

A: Yes, changes in appetite are a documented side effect. Official documents list a decreased appetite as a common adverse reaction, which is a factor contributing to reported changes in body weight.

Q: Are there any long-term side effects of Citalopam that I should know about?

A: All known adverse reactions, including those observed in clinical trials lasting up to a year, are described in regulatory documents. Furthermore, official labeling indicates that data on the effectiveness and safety of extended use is not fully established from controlled clinical trials.

Q: Does Citalopam require any special monitoring or blood tests?

A: Patients should be monitored for specific serious risks, including signs of bleeding and symptoms of low blood sodium (hyponatremia). Patients with pre-existing heart conditions may require closer monitoring, such as an ECG, due to the documented risk of heart rhythm changes.

Q: What are the signs of a serious reaction to Citalopam?

A: Official documents describe signs of serious reactions, which include symptoms of Serotonin Syndrome (confusion, fever, fast heartbeat, sweating) and signs of Hyponatremia (significant headache, difficulty concentrating, or confusion). Abnormal bleeding or bruising is also a documented risk.

Q: Is it possible to take Citalopam and still drive?

A: Citalopam may interfere with a person's ability to think clearly and perform motor tasks, and it can cause dizziness or drowsiness. Regulatory documents state that caution is needed when operating hazardous machinery, including driving, until a person is reasonably certain the drug does not impair their ability to do so.

Q: Does Citalopam affect blood pressure?

A: While changes in blood pressure are not listed as a common side effect, regulatory documents recommend close monitoring of blood pressure when Citalopam is combined with certain other medications, such as MAOIs, due to the potential for compounding risks.

Q: How is Citalopam different from older types of antidepressants?

A: Citalopam belongs to the class of Selective Serotonin Reuptake Inhibitors (SSRIs). Unlike older classes of antidepressants (such as MAOIs or TCAs), its primary and most significant function is described as to selectively target and block the reuptake of only the neurotransmitter serotonin.

Q: Is there any research on Citalopam's use for conditions other than depression?

A: Yes, regulatory documents describe that research has explored Citalopam in controlled trials for several conditions beyond its primary indication. This includes the structures of studies for Panic Disorder, Obsessive-Compulsive Disorder (OCD), and Social Anxiety Disorder (SAD).

Q: Do older adults typically use Citalopam?

A: Citalopam is used by older adults, but regulatory information specifies a restricted maximum daily dose for patients over 60 years of age. This restriction is mandated due to documented changes in how the body processes the drug in this age group, which can increase the risk of side effects.

Q: What is the risk of having an allergic reaction to Citalopam?

A: Citalopam is contraindicated (must not be used) in individuals who have a known hypersensitivity or allergic reaction to the drug or any of its components. Symptoms of an allergic reaction can range from a mild skin rash to severe reactions like difficulty breathing.

Q: How long does Citalopam stay in your system after stopping it?

A: Citalopam is cleared from the body slowly. Pharmacokinetic data show that the drug has a mean terminal half-life of approximately 35 hours. This means it takes about a day and a half for half of the drug to be eliminated from the system.

Q: Are there different ways Citalopam is supplied, like tablets or liquid?

A: Yes, Citalopam is supplied for oral administration in two forms. Regulatory information confirms it is available as both a tablet and an oral solution.

How should Citalopam be stored and disposed of?

How to Store and Dispose of Citalopam?

Citalopram tablets must be stored according to official regulatory requirements to ensure chemical stability.

Storage Conditions

  • Temperature: Store at controlled room temperature, specifically between 20 C and 25 C (68 F to 77 F). Brief excursions outside this range are permitted, but freezing and excessive heat must be avoided.
  • Container: Keep the medication in its original container, which must be tightly closed and stored away from moisture and direct light.
  • Safety: As a mandatory requirement, Citalopram must be kept out of the sight and reach of children.

Disposal Instructions

Proper disposal of unused or expired Citalopram is necessary to prevent environmental contamination. The medication must not be flushed down the toilet or poured into a drain. The recommended disposal method is to use a secure drug take-back program. If a program is unavailable, follow specific government guidelines for safe household disposal.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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