Citalopram oral solution for treatment of major depressive disorder in adults

Citalopram oral solution is a selective serotonin reuptake inhibitor (SSRI) used to treat major depressive disorder (MDD) in adults. It helps relieve symptoms of depression by increasing serotonin levels in the brain. This formulation is available as an oral solution containing 2 mg/mL of citalopram base.

Citalopram oral solution, USP is approved for the treatment of major depressive disorder in adult outpatients. It is intended for patients diagnosed with a major depressive episode characterized by persistent depressed or dysphoric mood lasting nearly every day for at least 2 weeks, along with other related symptoms.

This product is not approved for pediatric use and its safety and efficacy in hospitalized depressed patients have not been established. Long-term maintenance use up to 24 weeks has demonstrated efficacy in preventing relapse in adults following acute treatment.

Citalopram hydrobromide

Citalopram works by selectively inhibiting the reuptake of serotonin (5-HT) in the central nervous system, thereby increasing serotonin availability in the brain. Serotonin is a neurotransmitter involved in mood regulation. Citalopram’s antidepressant effects are mainly attributed to its (S)-enantiomer. It has minimal effects on other neurotransmitters such as norepinephrine and dopamine.

Citalopram oral solution contains 2 mg/mL of citalopram base. Dosage and administration should follow prescribing guidance specific to patient factors, with attention to maximum dose limits:

• Adults: Up to 40 mg/day; doses above 40 mg/day are not recommended due to risk of QT prolongation.
• Patients over 60 years, with hepatic impairment, or CYP2C19 poor metabolizers: Maximum recommended dose is 20 mg/day due to increased drug exposure and risk of cardiac effects.
• Steady state plasma concentrations are generally reached within one week with once-daily dosing.

Healthcare providers should individualize dosing and monitor for adverse effects.

• Use with MAO inhibitors intended to treat psychiatric disorders or within 14 days of stopping citalopram.
• Starting citalopram within 14 days of stopping an MAOI.
• Concurrent treatment with MAOIs such as linezolid or intravenous methylene blue.
• Concomitant use with pimozide.
• Hypersensitivity to citalopram or any inactive ingredients in the oral solution.

Suicidality and Clinical Worsening

Antidepressants, including citalopram, increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (up to age 24) during short-term treatment. The risk is not increased in adults over 24 and may be reduced in adults aged 65 and older. Patients should be closely monitored for worsening depression, suicidality, or unusual behavior, especially during initial treatment and dose changes. Families and caregivers should be advised to observe patients closely.

QT Prolongation and Cardiac Risks

Citalopram causes dose-dependent prolongation of the QT interval, which has been associated with serious heart arrhythmias like Torsade de Pointes and sudden death. Doses above 40 mg/day increase this risk. Use is contraindicated in patients with congenital long QT syndrome, bradycardia, hypokalemia, hypomagnesemia, recent myocardial infarction, uncompensated heart failure, or those on other QT-prolonging drugs.

Baseline and periodic electrolyte and ECG monitoring is recommended for at-risk patients. Discontinue citalopram if QTc exceeds 500 ms.

Serotonin Syndrome

Potentially life-threatening serotonin syndrome can occur with citalopram alone or especially when combined with other serotonergic drugs or MAO inhibitors. Symptoms include mental status changes, autonomic instability, neuromuscular abnormalities, seizures, and gastrointestinal symptoms. Avoid concomitant use with MAOIs, linezolid, or intravenous methylene blue. Discontinue citalopram prior to starting MAOI therapy.

Bipolar Disorder Screening

Screen patients for bipolar disorder prior to starting citalopram, as antidepressants may trigger manic episodes in susceptible individuals.

Other

Citalopram should not be used in conjunction with pimozide. Pupillary dilation may precipitate angle-closure glaucoma in susceptible patients.

Adverse reactions may include symptoms related to discontinuation such as dysphoric mood, irritability, agitation, dizziness, sensory disturbances (including electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, and hypomania. These symptoms are usually self-limiting but can be serious.

Citalopram is metabolized primarily by CYP3A4 and CYP2C19 enzymes. Potent inhibitors of these enzymes (e.g., ketoconazole, itraconazole, macrolide antibiotics, omeprazole) may decrease citalopram clearance and increase drug exposure, requiring dose adjustments (maximum 20 mg/day).

CYP2D6 inhibitors are unlikely to have significant effects. Concomitant use with other serotonergic drugs (e.g., triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, St. John's Wort) increases risk of serotonin syndrome.

Concomitant use with MAOIs, linezolid, intravenous methylene blue, or pimozide is contraindicated.