You may have some side effects when you start taking medicines. This does not mean you should stop taking them. Instead, talk with your doctor. Tell them about any side effects, such as nausea, vomiting, lightheadedness, loss of appetite, or sleep problems. Also tell your doctor if any medicine causes confusion, hallucinations, or involuntary movements. Some people have an unusual desire to gamble or engage in other obsessive behaviors. Your doctor may adjust the amount of medicine you take. Or, you may be given another type.