While most people tolerate Ativan^® (lorazepam) well, side effects can still occur during treatment with the medicine. A few common side effects of Ativan include dizziness, weakness, and unsteadiness. Some side effects of this drug are more serious and require immediate medical attention; be sure to report side effects such as seizures or suicidal thoughts to your healthcare provider right away. You should also let your heathcare provider know if you experience anything that "just does not seem right" during treatment with Ativan.