Citalopram: Comprehensive Guide
Drug Name
Generic Name
Citalopram
Brand Name(s)
Pakistan: Celexa, Cipram
India: Cipram, Citalopram
US: Celexa
UK: Cipramil
Pharmacological Class
Class
Antidepressant
Subclass
Selective Serotonin Reuptake Inhibitor (SSRI)
Mechanism of Action
Citalopram works by inhibiting the reuptake of serotonin (5-HT) in the brain, thereby increasing the levels of serotonin available to bind to serotonin receptors. This helps improve mood and alleviate symptoms of depression.
Indications
Primary Indications
- Major Depressive Disorder (MDD)
- Generalized Anxiety Disorder (GAD)
Off-label Uses
- Panic Disorder
- Obsessive-Compulsive Disorder (OCD)
- Premenstrual Dysphoric Disorder (PMDD)
Dosage and Administration
Standard Dosage
The initial dose for adults is typically 20 mg once daily, which may be increased to a maximum of 40 mg per day based on patient response and tolerability.
Route of Administration
Oral
Special Populations
Pediatric: Not recommended for use in children.
Geriatric: Lower doses may be required due to increased sensitivity and the risk of QT prolongation.
Pharmacokinetics
Absorption
Well absorbed, with peak plasma concentrations occurring 4 hours after administration.
Distribution
Widely distributed, with about 80% of the drug bound to plasma proteins.
Metabolism
Metabolized primarily in the liver by CYP3A4 and CYP2C19 enzymes.
Excretion
Excreted mainly in urine as metabolites.
Half-life
Approximately 35 hours in healthy adults.
Contraindications
Citalopram is contraindicated in patients with known hypersensitivity to the drug or other SSRIs. It should not be used in patients taking monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing an MAOI.
Warnings and Precautions
Citalopram carries a black box warning for increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Caution is advised in patients with a history of bipolar disorder, seizures, or liver impairment. It may also cause QT prolongation.
Side Effects
Common Side Effects
- Nausea
- Insomnia
- Dry mouth
- Fatigue
- Increased sweating
- Diarrhea
Serious Side Effects
- Severe allergic reactions
- Seizures
- QT prolongation
- Serotonin syndrome
- Hyponatremia
Drug Interactions
Major Interactions
- Monoamine oxidase inhibitors (MAOIs)
- Pimozide
- Other SSRIs or SNRIs
Moderate Interactions
- Tricyclic antidepressants
- Anticoagulants
- NSAIDs
Minor Interactions
- Alcohol
- Herbal supplements (e.g., St. John's Wort)
Pregnancy and Lactation
Pregnancy Category
Category C: Risk cannot be ruled out. Citalopram should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Breastfeeding Considerations
Citalopram is excreted in breast milk. Caution should be exercised when administered to a nursing woman, considering the benefits of breastfeeding and the potential risks to the infant.
Patient Counseling Information
Key Points for Patients
- Inform patients about the risk of suicidal thoughts and behaviors.
- Advise patients to report any unusual changes in mood or behavior.
- Discuss the importance of adherence to prescribed dosing regimen.
- Inform patients about the potential side effects and drug interactions.