It may need time for the medicine to help. Turn to your doctor or pharmacist for more details. This medication belongs to a class of medications called tricyclic antidepressants. Take the drug only as prescribed because dosage and schedule may vary depending on your condition and other factors. QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away. It is important to continue taking this medication even if you feel well. To prevent constipation, maintain a diet adequate in fiber, drink plenty of water, and exercise. Mix only what you need for each dose. Do not prepare a supply for future use.