u have been prescribed feliz 10 mg and epitril 0.5 mg for your nucturnal panic attacks.. feliz is a brand of escitalopram which is a very safe antidepressant SSRI medication.. as a rule every medication has its side effects and so with feiz.. common side effects upon starting it may be some gastrointestinal disturbances like feeling of nausea, epigastric burning, acidity, dizziness, sleep disturbancies, yawning, dry mouth etc.. but these side effects disappeares with regular use of the drug.. according to my understanding u r interested in knowing the long term n serious side effects of escitalopram.. there are chances that u may have decrease sexual desire, delayed ejaculation of semen during sex, very stiff rigid muscles, high fever, difficulty walking, tremors, drowsiness. it can cause hyponatremia due to SIADH [syndrome of inappropriate antidiuretic hormone secretion] symptoms of which are muscle cramps, rigidity, confusion, delirium ,disorientation. it also increase the bleeding risk when taken with drugs like aspirin n N-SAIDS it can cause harmful syndrome known as serotonin syndrome when taken with other serotonergic drugs like SNRIs, MAO inhibitors. so these r the serious side effects but they are not very common so u shudnt bothering about these.. take medications they are more beneficial then harmful.