Yes, both Lexapro (escitalopram) and olanzapine can cause night sweats, but the evidence is much stronger for Lexapro.
Lexapro (Escitalopram) and Night Sweats
Lexapro definitively causes increased sweating, including night sweats, as a well-documented adverse effect. The FDA drug label explicitly lists "sweating increased" as one of the most common side effects, occurring in approximately 5% of patients taking Lexapro—more than twice the rate seen with placebo 1. This sweating can manifest as both daytime hyperhidrosis and night sweats.
Evidence Strength for Lexapro:
- Guideline-level evidence confirms that SSRIs as a class commonly cause sweating, tremors, and other autonomic symptoms 2
- FDA labeling documents 5% incidence of increased sweating with escitalopram versus 2% with placebo 1
- Research evidence from a primary care study of 413 older adults found SSRIs were significantly associated with night sweats (OR 3.01; 95% CI 1.26-7.19) 3
- Multiple case reports document escitalopram-induced excessive sweating that resolved with drug discontinuation 4, 5
The mechanism appears related to serotonergic effects on central thermoregulatory centers and autonomic nervous system function 6.
Olanzapine and Night Sweats
Olanzapine does not have well-documented evidence linking it to night sweats or increased sweating. While olanzapine causes numerous side effects including drowsiness, orthostatic hypotension, weight gain, and metabolic effects 7, sweating is not listed among its common adverse effects in clinical guidelines or research literature.
What Olanzapine Actually Causes:
- Drowsiness and sedation
- Orthostatic hypotension
- Metabolic effects (weight gain, hyperglycemia, dyslipidemia) with long-term use
- Anticholinergic effects (which would theoretically reduce sweating)
- Rare cases of edema 8
The anticholinergic properties of olanzapine would theoretically make sweating less likely, as acetylcholine is the primary neurotransmitter mediating eccrine sweat gland function 6.
Clinical Management Approach
If a patient on Lexapro reports night sweats:
- Confirm the temporal relationship (sweating typically begins within weeks of starting or increasing the dose)
- Rule out other causes: infection, malignancy, hyperthyroidism, menopause, other medications
- Consider dose reduction if clinically appropriate
- If dose reduction is ineffective or inappropriate, consider switching to a different antidepressant (bupropion or mirtazapine may have lower sweating rates) 9, 5
- If the antidepressant must be continued, adjunctive treatments include:
If a patient on olanzapine reports night sweats:
- Look for alternative explanations first, as this is not a recognized side effect of olanzapine
- Consider other medications, underlying medical conditions, or environmental factors
Important Caveat:
The 2015 guideline notes that about 63% of patients on second-generation antidepressants experience at least one adverse effect, with sweating being commonly reported alongside diarrhea, dizziness, dry mouth, fatigue, headache, and sexual dysfunction 9. This underscores that sweating with SSRIs like Lexapro is an expected and frequent occurrence, not a rare idiosyncratic reaction.