Common side effects of Ativan include drowsiness, dizziness, confusion, and muscle weakness. In higher doses or prolonged use, it can lead to memory impairment, sedation, and dependence. Mixing Ativan with alcohol or other depressants increases the risk of overdose, which can cause respiratory depression or even coma. Patients should avoid activities requiring full alertness, such as driving, while taking Ativan to prevent accidents or impaired coordination.