Hi & Welcome. Taken together they may cause a harmful interaction. Incomplete data like age, purpose of taking the medications??? Lexapro (Escitalopram) is a selective serotonin reuptake inhibitor (SSRI) commonly prescribed in the treatment of depression, generalized anxiety disorder, obsessive compulsive disorder and other conditions. Cymbalta (Duloxetine) is a selective serotonin and norepinephrine reuptake inhibitor antidepressant (SSNRI) commonly prescribed to treat depression, general anxiety disorder, fibromyalgia, diabetic neuropathy and other conditions. Taking Lexapro along with Cymbalta can increase the risk of serious condition called the serotonin syndrome which is characterized by confusion, hallucination, seizures, high BP, increased heart rate, fever, excessive sweating, shivering, blurred vision, muscle rigidity, tremor, incoordination, stomach cramp, nausea, vomiting, and diarrhea. In severe cases result coma and even death may occur. You should seek immediate medical attention if you experience these symptoms while taking the medications. Her treating doctor was already aware of the risks, so consult him/her again for proper clinical evaluation and use of a safer medication to control your daughter s problem. Hope this will solve her problem. A feed back is appreciated.