Lorazepam produces a calming effect on the brain and nerves, which helps to reduce anxiety symptoms and treat seizures. How is lorazepam supplied (dosage forms)? Brands and other names Ativan. Ativan (lorazepam) belongs to a class of medications called benzodiazepines. It is thought that benzodiazepines work by enhancing the activity of certain neurotransmitters in the brain. Ativan is used in adults and children at least 12 years old to treat anxiety disorders. Lorazepam belongs to a class of medications called benzodiazepines. It is thought that benzodiazepines work by enhancing the activity of certain neurotransmitters in the brain. Lorazepam is used in adults and children at least 12 years old to treat anxiety disorders. How long does it take for lorazepam to work? When starting lorazepam, anxiety or insomnia may improve rapidly or over a period of days or within hours of the first dose of medication. Lorazepam is a benzodiazepine that slows down nervous system activity to reduce anxiety, promote calm, and help with sleep. It works within about 30 to 60 minutes when taken by mouth, and its effects typically last six to eight hours. Lorazepam is a benzodiazepine medication primarily approved to treat anxiety disorders. Its calming effect on the brain also makes it useful in several other medical situations, from stopping prolonged seizures to easing alcohol withdrawal and reducing nausea during chemotherapy. Lorazepam is a medicine used to treat severe anxiety. It's only available with a prescription. Lorazepam can be used: Lorazepam is a type of medicine called a benzodiazepine. It works by increasing the effect of a calming chemical in your brain. This can help you feel more relaxed or sleepy. Lorazepam is used in the short-term management of severe anxiety. In the US, the Food and Drug Administration (FDA) advises against use of benzodiazepines such as lorazepam for longer than four weeks. [25][31] It is fast-acting, and useful in treating fast-onset anxiety and panic attacks. [32] Lorazepam is a prescription anti-anxiety drug used to treat anxiety disorders and anxiety associated with depression; insomnia, panic attacks, and seizures. Common side effects are weakness, dizziness, unsteadiness, and headache. Lorazepam is a benzodiazepine that works in the brain to relieve symptoms of anxiety. Benzodiazepines are central nervous system (CNS) depressants, which are medicines that slow down the nervous system. This medicine is available only with your doctor's prescription.