Hi & Welcome. Taken together these antidepressant drugs may cause a serious side effect called Serotonin syndrome. Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI). It works by restoring the balance of serotonin and norepinephrine in the brain and hence used in the treatment of depression. Escitalopram is a selective serotonin reuptake inhibitors (SSRI) which works by increasing the levels of serotonin in the brain and it is also used in the treatment of depression and anxiety disorders. If taken together they can cause high levels of serotonin to accumulate in your body causing a serious adverse effect called Serotonin syndrome which is characterized by agitation, sweating, confusion, tremors, restlessness, convulsions, severe muscle rigidity, raised body temperature and motor incoordination, extremely high BP, increased heart beats, etc. Severe cases may result in coma and even death. So, avoid taking these medications at the same time and consult your treating doctor for dose adjustment or use of other alternate effective but safer medications to treat depression. Hope this answers your query.