Citalopram

Antidepressant Drug

Drug class: Selective Serotonin Reuptake Inhibitor

Citalopram (CIPRAM)（中文：西酞普蘭）

Pronunciation

Citalopram 20mg

Common Strengths of Citalopram Tablet

Citalopram are available in the following strengths:

• Tablets: 10 mg, 20 mg, 40 mg
• Oral solution: 10 mg/5 mL

Drug Trade Names of Citalopram Tablet

CIPRAM

Drug Usage

• Major depressive disorder (MDD) in adults
• Off-label uses: Generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), panic disorder, social anxiety disorder, premenstrual dysphoric disorder (PMDD)

Mechanism of Action

It works by increasing serotonin levels in the brain by inhibiting its reuptake into presynaptic neurons, thereby enhancing serotonergic activity.

Route of Administration

Oral (tablets and solution)

Dosages

• Initial dose: 20 mg once daily
• Maintenance dose: 20 - 40 mg once daily
• Maximum dose: 40 mg/day
• Elderly: Recommended dose is 20 mg/day

Side Effects

Frequency	Adverse reactions
Common	Nausea
	Dry mouth
	Increased sweating
	Drowsiness
	Insomnia
	Dizziness
	Fatigue
	Weakness
	Tremor (shaking)
	Sexual dysfunction (e.g. decreased libido, difficulty achieving orgasm, erectile dysfunction)
	Diarrhea or constipation
	Loss of appetite
Serious	Allergic reactions: Symptoms such as hives, difficulty breathing, and swelling of the face, lips, tongue, or throat
	Serotonin syndrome: Symptoms include agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea
	QT prolongation: A dangerous heart rhythm condition that can lead to torsades de pointes. Symptoms may include fainting, dizziness, or irregular heartbeat
	Suicidal thoughts or behaviors: Particularly in young adults, teenagers, and children, especially when starting the medication or adjusting the dose
	Manic episodes: Symptoms include racing thoughts, increased energy, decreased need for sleep, risk-taking behavior, and being unusually talkative or agitated
	Severe nervous system reactions: Symptoms include very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, and tremors
	Unusual bleeding: Including nosebleeds, bleeding gums, abnormal vaginal bleeding, or any bleeding that does not stop
	Low blood sodium (hyponatremia): Symptoms include headache, confusion, problems with thinking or memory, weakness, and feeling unsteady
	Seizures

Pharmacokinetics

• Peak plasma level is approximately 4 hours after oral dosing
• Metabolism: Citalopram is primarily metabolized in the liver by CYP3A4 and CYP2C19.
• Elimination: Half-life is about 35 hours. Approximately 12-23% of an oral dose is excreted unchanged in urine and about 10% is excreted in feces.

These pharmacokinetic properties contribute to citalopram's once-daily dosing regimen.

Onset Time and Duration of drug action

• Onset: Therapeutic effects typically observed within 1-4 weeks.
• Duration: Steady-state achieved within 1 week.

Drug Precautions

Pregnancy

May cause complications such as persistent pulmonary hypertension of the newborn (PPHN) and poor neonatal adaptation if used in the third trimester.

Breastfeeding

Use with caution; citalopram is excreted in human milk.

Children and Elderly

• Children: Safety and effectiveness not established in pediatric patients
• Elderly: Recommended dose is 20 mg/day due to increased sensitivity

Renal Impairment

No dosage adjustment necessary for mild-to-moderate impairment; use with caution in severe impairment

Monitoring Requirements

Citalopram, a selective serotonin reuptake inhibitor (SSRI), requires careful monitoring and management to ensure patient safety and therapeutic efficacy. Here are the key aspects of moritoring and management:

Before Treatment

• Electrolytes:
  • Monitor and evaluate baseline levels of potassium and sodium
  • Correct any hypokalemia or hypomagnesemia before starting treatment
  • Periodically re-evaluate electrolytes, especially in patients at riks for electrolyte disturbances
• ECG Monitoring:
  • Perform an ECG to check for QT prolongation in patients with congenital long QT syndrome, bradycardia, hypokalemia, hypomagnesemia, recent acute myocardial infarction, or uncompensated heart failure.
  • Avoid citalopram or use with caution in patients taking other QT-prolonging drugs

Drug Treatment

• Mental Health Monitoring:
  • Assess and monitor for worsening depression, suicidality, or unusual changes in behavior, particularly during the initial few months of therapy or when adjusting doses
  • Weekly face-to-face contact is recommended during the first month, followed by bi-weekly visits for the next month, and then at 3-month intervals
• Weight and Growth:
  • Regularly monitor weight and growth in children and adolescents undergoing treatment
• Psychiatric Assessment:
  • Use standardized scales to screen for anxiety and depression and to monitor response to therapy, such as:
  • Patient Health Questionnaire (PHQ-9)
  • Generalized Anxiety Disorder 7 score (GAD-7)
  • Hamilton Anxiety Scale (HAM-A)
• Toxicity and Overdose Management
  • Serotonin Syndrome
    • Be vigilant for signs of serotonin syndrome, especially if the patient is on other serotonergic medications.
    • Symptoms include agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea
  • Patient Education
    • Educate patients about the risks of combining citalopram with alcohol, sedatives, and other antidepressants
• Special Considerations:
  • Elderly Patients:
    • The maximum recommended dose for patients older than 60 years is 20 mg per day due to increased risk of QT prolongation
    • Monitor for persistent QTc measurements greater than 500 ms and discontinue citalopram if necessary
  • Monitor for abnormal bleeding