What is Morcet (escitalopram), its mechanism of action, therapeutic effects, adverse effects, and does it cause weight gain?

Morcet (Escitalopram): Overview and Clinical Profile

Morcet is escitalopram, a highly selective SSRI antidepressant that works by blocking serotonin reuptake in the brain, and while it can cause weight changes, it is generally considered weight-neutral compared to other antidepressants. 1, 2

Mechanism of Action

Escitalopram potentiates serotonergic activity in the central nervous system by inhibiting neuronal reuptake of serotonin (5-HT) at the serotonin transporter (SERT). 3 This is the most selective SSRI available, demonstrating at least 100-fold greater potency than its R-enantiomer in blocking serotonin reuptake. 3, 4

Unique Pharmacological Properties

• Escitalopram has minimal effects on norepinephrine and dopamine reuptake, making it highly selective for serotonin. 3
• It has no or very low affinity for other receptor systems including alpha- and beta-adrenergic, dopamine, histamine, muscarinic, and benzodiazepine receptors. 3
• This selective binding profile explains why escitalopram avoids many anticholinergic, sedative, and cardiovascular side effects seen with other psychotropic medications. 3

Therapeutic Effects

Escitalopram demonstrates robust efficacy in treating major depressive disorder and anxiety disorders, with a relatively rapid onset of antidepressant action. 5, 6

Clinical Efficacy

• In controlled trials, escitalopram was more effective than placebo and at least as effective as other SSRIs (fluoxetine, paroxetine, sertraline) and SNRIs (venlafaxine, duloxetine) for major depression. 5
• Peak blood levels occur approximately 5 hours after oral administration, with steady-state concentrations achieved within one week of daily dosing. 3
• The mean terminal half-life is 27-32 hours, supporting once-daily dosing. 3, 7

Adverse Effects

The most common adverse effects include nausea (15%), insomnia (9%), ejaculation disorder (9% in males), diarrhea (8%), dizziness (5%), and fatigue (5%). 3

Common Side Effects (≥5% and twice placebo rate)

• Gastrointestinal: Nausea, diarrhea, constipation, indigestion 3
• Sexual dysfunction: Ejaculatory delay (primary complaint), decreased libido, anorgasmia 3
• Sleep disturbances: Insomnia, somnolence 3
• General: Fatigue, increased sweating 3
• Neurological: Dizziness 3

Discontinuation Rates

• In adult depression trials, 6% discontinued due to adverse events versus 2% on placebo. 3
• Nausea (2%) and ejaculation disorder (2%) were the most common reasons for discontinuation. 3

Important Safety Considerations

• Serotonin syndrome risk: Avoid combining with triptans, MAOIs, other serotonergic drugs, tramadol, tryptophan, or St. John's Wort. 3
• Bleeding risk: Monitor patients with bleeding disorders or those on anticoagulants. 3
• Seizure precautions: Use caution in patients with seizure history. 3
• Pregnancy considerations: Late pregnancy use may increase risk of neonatal complications. 3

Weight Gain Profile

Escitalopram is generally considered weight-neutral, making it a preferred choice when weight concerns are present, though it is not as favorable as bupropion which consistently promotes weight loss. 1, 2

Comparative Weight Effects Among Antidepressants

When weight is a significant concern, the clinical algorithm prioritizes:

1. First-line: Bupropion (the only antidepressant consistently associated with weight loss, with 23% of patients losing ≥5 lbs versus 11% on placebo) 1, 8

2. Second-line (if bupropion contraindicated): Escitalopram, fluoxetine, or sertraline—all demonstrate initial weight loss transitioning to weight neutrality with long-term use 1, 2, 8

3. Avoid: Paroxetine (highest SSRI weight gain risk), mirtazapine, amitriptyline, and MAOIs (all associated with significant weight gain) 1, 2, 8

Clinical Caveats on Weight

• Not all SSRIs behave identically regarding metabolic effects—escitalopram differs significantly from paroxetine despite being in the same drug class. 8
• Monitor weight at baseline, then at 3 months to assess early response. 2
• If ≥5% weight gain occurs, consider switching agents rather than dose reduction. 2
• Escitalopram has less effect on metabolism of other medications compared to other SSRIs, making it preferable when polypharmacy is necessary. 2, 8

Pediatric Considerations

• Monitor height and weight during treatment in children and adolescents, as possible slowed growth rate and weight changes have been reported. 3