Citalopram belongs to a group of medications called selective serotonin reuptake inhibitors (SSRIs). It is used to treat depression. SSRIs improve depression by increasing the amount of serotonin (a neurotransmitter) in certain areas of the brain, which in turn improves the ability of the brain to transmit messages from one nerve cell to another. Increased serotonin levels can help improve mood.

Although you may start feeling better within a few weeks of treatment, the full effects of the medication may not be evident until several weeks of treatment have passed.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual recommended starting dose is 20 mg daily. Your doctor may increase the dose as appropriate, based on how well it is working for you and whether you are experiencing side effects. The maximum recommended dose is 40 mg daily. Continue to take the medication regularly, even if you don’t feel as though the medication is working. It may take several weeks to see a noticeable improvement in your mood.

Citalopram should be taken once daily either in the morning or evening, but at the same time every day. It should be swallowed whole with water and may be taken with food or on an empty stomach.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Citalopram can cause withdrawal effects such as agitation, anxiety, difficulty concentrating, nausea, and vomiting, if it is stopped suddenly. If it becomes necessary for you to stop taking citalopram, ask your doctor to advise you how best to gradually reduce the dose to avoid withdrawal effects.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from moisture, and keep it out of the reach of children.

Do not take citalopram if you:  

• are allergic to citalopram or any ingredients of the medication
• are taking pimozide (an antipsychotic medication)
• have taken a type of medication known as an MAO inhibitor (e.g., phenelzine, tranylcypromine, moclobemide) within the past 2 weeks - do not start treatment with an MAO inhibitor until at least 2 weeks after discontinuing citalopram treatment
• have a heart rhythm condition known as "long QT syndrome"

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• diarrhea
• dry mouth
• fatigue
• increased sweating
• nausea
• sexual dysfunction including:
• decreased libido (sex drive)
• erectile dysfunction (difficulty getting or keeping an erection)
• inability to have an orgasm
• shakiness
• sleepiness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• feeling restless or unable to sit still
• heavy vaginal bleeding after giving birth
• new or worsened emotional or behavioural problems
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don’t stop bleeding)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• symptoms of glaucoma (e.g., blurred vision, seeing halos of bright colours around lights, red eyes, increased pressure in your eyes, eye pain or discomfort)
• symptoms of heart rhythm changes (e.g., pounding heartbeat, dizziness, fainting, seizures)
• symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heartbeat, weakness)
• symptoms of low sodium in the blood (e.g., tiredness; weakness; confusion; or achy, stiff, or uncoordinated muscles)
• symptoms of mania (e.g., decreased need for sleep, elevated or irritable mood, racing thoughts)
• symptoms of suddenly stopping the medication (e.g., dizziness, abnormal dreams, numbness, electric shock feelings, agitation, anxiety, difficulty concentrating, headache, tremor, nausea, vomiting, and sweating)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizure or convulsions
• serotonin or neuroleptic malignant syndrome (signs include agitation, confusion, diarrhea, fever, overactive reflexes, poor coordination, restlessness, shivering, sweating, talking or acting with excitement you cannot control, trembling or shaking, twitching)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools; spitting up of blood; vomiting blood or material that looks like coffee grounds)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
• thoughts of suicide or hurting yourself

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Abnormal heart rhythm: Citalopram may cause an abnormal heart rhythm, especially at higher doses. Your doctor may occasionally monitor your heart rate and rhythm with a test called an electrocardiogram. People with a history of a heart rhythm disturbance called QT prolongation should not take this medication. If you have congestive heart failure, slow heart rhythm, are at risk of low potassium or magnesium levels because of certain illnesses or medications, or you are taking certain medications that can affect the heart rhythm (e.g., amiodarone, sotalol), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Bleeding disorders: Citalopram may increase bruising and cuts may take longer to stop bleeding. If you have a bleeding disorder or a history of bleeding problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Diabetes: Citalopram may affect blood sugar levels (hyperglycemia and hypoglycemia). If you have diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Drowsiness/reduced alertness: Citalopram may cause drowsiness for some who take it. Avoid activities that require mental alertness, judgment, and physical coordination (such as driving a car or performing hazardous tasks) until you establish how citalopram affects you.

Fractures: There is some evidence that people taking citalopram or other medications in the same class may be at an increased risk of fractures (broken bones) when they first start to take this medication and after long term use. If you are a senior, have osteoporosis, or have other risk factors for bone fractures, take extra care to avoid falling by sitting or lying down if you feel dizzy or lightheaded. Contact your doctor if you experience dizziness or lightheadedness frequently.

Glaucoma: This medication may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking this medication.

Heart disease: Citalopram may cause decreased heart rate for some people, which may make symptoms of heart disease worse. If you have heart disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: The effect of citalopram when taken by people with severely decreased kidney function has not been well studied. If you have poor kidney function or severe kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Mania or hypomania: Citalopram may cause activation of mania or hypomania. If you have a history of mania or bipolar disorder, you should be closely monitored by your doctor while taking this medication.

Seizures: Citalopram may increase the risk of developing seizures, particularly if you have a history of seizures. If you have a seizure disorder or have had seizures in the past, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you develop seizures, contact your doctor or seek medical attention immediately.

Serotonin syndrome: Severe reactions are possible when citalopram is combined with other medications that act on serotonin, such as tricyclic antidepressants and serotonin reuptake inhibitors (medications used to treat depression). These combinations must be avoided. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, and changes in mental state including delirium and agitation. Coma and death are possible.

Stopping the medication: Citalopram should not be stopped abruptly due to the risk of discontinuation symptoms. A gradual decrease in the dose over a period of time is recommended. If you are thinking of stopping the medication, talk to your doctor or pharmacist about how to do this safely.

Suicidal or agitated behaviour: People taking this medication may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves) or they may want to hurt themselves or others. These symptoms may occur within several weeks after people start taking this medication. You should be closely monitored by your doctor for emotional and behavioural changes. If you experience any of these symptoms or notice them in a family member who is taking this medication, contact your doctor immediately.

Pregnancy: The safe use of citalopram during pregnancy has not been established. This medication should not be used during pregnancy unless the benefits outweigh the risks. Newborn babies may experience serious adverse effects including withdrawal symptoms and other complications resulting in prolonged hospitalization if the mother is taking citalopram during the 3 months before the baby is born.

Women who take citalopram during the last month of pregnancy have an increased risk of bleeding after the baby is born. Doctors and pregnant women should carefully consider the benefits and the risks of all treatment options. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking citalopram, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children and is not indicated for use in children under the age of 18. There have been reports that using this and similar medications in children under 18 years old may cause behavioural and emotional changes such as suicidal thoughts and behaviour.

Seniors: Because this medication is removed from the body by the kidney and liver, seniors may be at increased risk of side effects if they use this medication. Your doctor may decide to start with a lower dose. If you are over 65, discuss with your doctor whether any special monitoring is required.

There may be an interaction between citalopram and any of the following:             

• alcohol
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• anagrelide
• antiarrhythmic medications (e.g., amiodarone, disopyramide, dronedarone, flecainide, mexiletine, procainamide, propafenone, quinidine, sotalol)
• anticoagulants (e.g., apixaban, dabigatran, edoxaban, rivaroxaban, warfarin)
• antihistamines (e.g., cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
• antiplatelets (e.g., acetylsalicylic acid [ASA], clopidogrel, ticagrelor)
• antipsychotics (e.g., aripiprazole, chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• antiseizure medications (e.g., carbamazepine, clobazam, levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide)
• apalutamide
• "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole)
• barbiturates (e.g., butalbital, pentobarbital, phenobarbital)
• benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
• bromocriptine
• bupropion
• buspirone
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• celecoxib
• chloral hydrate
• chloroquine
• cimetidine
• cobicistat
• conivaptan
• desmopressin
• dexmethylphenidate
• dextromethorphan
• diabetes medications (e.g., acarbose, canagliflozin,  glyburide, insulin, liraglutide, lixisenatide, metformin, rosiglitazone)
• domperidone
• enzalutamide
• ergot alkaloids (e.g., ergotamine, dihydroergotamine)
• formoterol
• glucosamine
• grapefruit juice
• heparin
• herbs with anti-platelet properties (e.g., gingko biloba, garlic, ginger)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• hydroxychloroquine
• linezolid
• lithium
• lumacaftor and ivacaftor
• macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
• methadone
• methylene blue
• methylphenidate
• metyrosine
• mifepristone
• mirabegron
• mirtazapine
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• multivitamins with minerals
• muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine)
• narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone, tapentadol, tramadol)
• nonsteroidal anti-inflammatory medications (e.g., diclofenac, ibuprofen, ketoprofen, naproxen)
• obinutuzumab
• omega-3 fatty acids
• omeprazole
• ozanimod
• pentamidine
• pentoxifylline
• prasugrel
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, moxifloxacin, ofloxacin)
• St. John's wort
• salmeterol
• scopolamine
• other selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• serotonin antagonists (anti-emetic medications; e.g., granisetron, ondansetron)
• serotonin-norepinephrine reuptake inhibitor (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
• somatostatin-like medications (e.g., lanreotide, octreotide, pasireotide)
  
• stiripentol
• sulfamethoxazole
• thiazide diuretics (water pills; e.g., hydrochlorothiazide, indapamide, metolazone)
• thyroid replacements (e.g., dessicated thyroid, levothyroxine)
• trazodone
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• "triptan" migraine medications (e.g., almotriptan, eletriptan, sumatriptan)
• tryptophan
• tyrosine kinase inhibitors (e.g., dasatinib, imatinib, nilotinib, sunitinib)
• vitamin E
• zolpidem
• zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.