Lexapro Does Not Interfere with Copeptin Testing
There is no evidence that escitalopram (Lexapro) affects copeptin test accuracy, and copeptin is not recommended for routine use in acute myocardial infarction diagnosis when high-sensitivity troponin assays are available.
Current Guidelines on Copeptin Testing
The 2020 ESC Guidelines explicitly state that copeptin should NOT be routinely measured for initial diagnostic purposes in addition to high-sensitivity cardiac troponin (hs-cTn) 1. This represents a Class III recommendation (not recommended) with Level B evidence 1.
- Copeptin may only be considered as an additional biomarker for early rule-out of MI in settings where hs-cTn assays are unavailable (Class IIa recommendation) 1
- The dual-marker approach with copeptin provides minimal incremental value when used with sensitive or high-sensitivity troponin assays 2
Understanding Copeptin as a Biomarker
Copeptin functions as a stress hormone marker that reflects endogenous stress levels 3, 2:
- It is released in equimolar amounts with vasopressin (AVP) and mirrors AVP production 3
- Copeptin rises rapidly in multiple acute disorders including acute myocardial infarction 2
- It serves as a quantitative marker of the body's stress response to acute illness 3
No Known Drug Interactions with SSRIs
There is no documented evidence in the medical literature that SSRIs, including escitalopram, interfere with copeptin measurements 3, 2, 4:
- Copeptin is a stable glycosylated peptide derived from the AVP precursor that remains stable for several days at room temperature 4
- The physiological release of copeptin is triggered by stressors that activate the hypothalamo-pituitary-adrenal axis 3
- SSRIs work through serotonin reuptake inhibition and do not directly affect vasopressin or copeptin release mechanisms 5
Clinical Context Matters
While copeptin levels must always be interpreted within the clinical setting 3, this refers to the patient's acute illness severity rather than medication effects:
- Copeptin accurately mirrors disease severity and discriminates patients with unfavorable outcomes 3
- Different acute conditions (sepsis, pneumonia, stroke, syncope) show elevated copeptin levels 3, 6
- The stress response measured by copeptin is independent of chronic SSRI therapy 3
Practical Recommendation
If copeptin testing is being considered (which is generally not recommended per current guidelines), there is no need to discontinue or adjust escitalopram therapy 1. The focus should instead be on using validated high-sensitivity troponin algorithms (0h/1h or 0h/2h protocols) for acute coronary syndrome diagnosis 1.