Ativan is an antianxiety medication for managing and treating anxiety and panic disorders. Buy Ativan Online. It belongs to the group of drugs known as benzodiazepine, which effectively manages the GABA levels in the brain and helps alleviate anxiety symptoms. In the market, it is available under different brand names; still, Ativan is one of the widely prescribed prescriptions in the USA. The effect of this drug begins in 50 to 60 minutes, and its impact lasts in the system for up to 12 to 24 hours or approximately one day.