Hello Dear. Doxylamine is an antihistamine, used to relieve symptoms of allergy, hay fever, and the common cold. The most common side effect of this drug is drowsiness. But it is not a drug which is commonly given to treat insomnia. I advice your brother not to experiment with different kinds of medicine on his own. He needs to consult a doctor who will assess the reason for his insomnia. If he is having depression or any other thing which is bothering him, he may need counselling and appropriate medication. But let him not experiment on his own. Lorazepam is a sedative which is given for insomnia and to treat anxiety and depression. Xarelto is used to prevent or treat a type of blood clot called deep vein thrombosis (DVT), which can lead to blood clots in the lungs (pulmonary embolism). Lisinopril and metoprolol is used to treat hypertension. Kindly suggest your brother to meet a physician at the earliest. Hope i have answered your question. Feel free to contact me if you have any more questions. I ll be glad to help you. All the best With warm regards Dr Sanjay Kini