From the Guidelines
No, Lexapro (escitalopram) is not an acceptable adjunct to fluoxetine 40 mg. Both medications are selective serotonin reuptake inhibitors (SSRIs), and combining them significantly increases the risk of serotonin syndrome, a potentially life-threatening condition characterized by agitation, confusion, rapid heart rate, high blood pressure, dilated pupils, muscle rigidity, and hyperthermia 1.
Key Considerations
- Using two SSRIs simultaneously provides minimal additional therapeutic benefit while substantially increasing side effects and risks.
- The concomitant administration of any of the SSRIs with any of the monoamine oxidase inhibitors (MAOIs) is contraindicated because of increased risk of serotonin syndrome, and although Lexapro is not an MAOI, the principle of caution with serotonergic drugs applies 1.
- If a patient is not responding adequately to fluoxetine 40 mg, better options would include either switching to a different antidepressant class (such as an SNRI like venlafaxine or duloxetine), or augmenting with medications from different classes such as bupropion, mirtazapine, or certain atypical antipsychotics.
Clinical Approach
- Any medication changes should be done gradually under medical supervision, with careful monitoring for withdrawal symptoms or adverse effects during the transition period.
- Medical education, training, and experience are necessary to safely and effectively prescribe antidepressant medications, especially when considering combinations or switches 1.
- A conservative medication trial for mild to moderate anxiety presentations may entail increasing the dose as tolerated within the therapeutic dosage range in the smallest available increments at approximately 1- to 2-week intervals when prescribing shorter half-life SSRIs, to approximately 3- to 4-week intervals when prescribing longer half-life SSRIs like fluoxetine until the benefit-to-harm ratio is optimized and remission is achieved 1.
From the Research
Acceptability of Lexapro as an Adjunct to Fluoxetine
- Lexapro, also known as escitalopram, is a selective serotonin reuptake inhibitor (SSRI) that has been shown to be effective in the management of major depressive disorder (MDD) in adults 2.
- There is no direct evidence in the provided studies to suggest that Lexapro is an acceptable adjunct to fluoxetine 40 mg.
- However, it is known that combining two SSRIs is not a common practice and may increase the risk of adverse effects such as serotonin syndrome 3, 4.
- Fluoxetine has been shown to be effective in the treatment of MDD, but it may not be effective for all patients, and augmentation strategies may be considered in cases of treatment-resistant depression 5.
- The use of atypical antipsychotics, such as olanzapine, in combination with fluoxetine has been shown to be effective in reducing symptoms of depression in patients with treatment-resistant depression 5.
- Escitalopram has been shown to be at least as effective as other SSRIs, including fluoxetine, in the treatment of MDD, and it has a predictable tolerability profile with generally mild to moderate and transient adverse events 2.
Potential Risks and Benefits
- The potential benefits of using Lexapro as an adjunct to fluoxetine 40 mg are unclear and would need to be weighed against the potential risks of adverse effects such as serotonin syndrome 3, 4.
- The decision to use Lexapro as an adjunct to fluoxetine 40 mg should be made on a case-by-case basis, taking into account the individual patient's response to treatment and medical history 5, 2.
- Further research would be needed to determine the safety and efficacy of using Lexapro as an adjunct to fluoxetine 40 mg.