It takes approximately 18–36 hours for the benzodiazepine to remove itself from the body.

After its introduction in 1977, lorazepam's principal use was in treating anxiety. Lorazepam-glucuronide is more water-soluble than its precursor and, therefore, gets more widely distributed in the body, leading to a longer half-life than lorazepam. Intravenous injections should be given slowly and patients closely monitored for side effects, such as respiratory depression, hypotension, or loss of airway control. Lorazepam given to pregnant women antenatally may cause floppy infant syndrome in the neonate, or respiratory depression necessitating ventilation. Important information about AtivanDo not use Ativan if you are allergic to lorazepam or to other benzodiazepines, such as alprazolam (Xanax), chlordiazepoxide (Librium), clorazepate (Tranxene), diazepam (Valium), or oxazepam (Serax). Lorazepam is sometimes used as an alternative to haloperidol when there is the need for rapid sedation of violent or agitated individuals, but haloperidol plus promethazine is preferred due to better effectiveness and due to lorazepam's adverse effects on respiratory function. Patients are ideally nursed in a kind, non-frustrating environment, since, when given or taken in high doses, benzodiazepines are more likely to cause paradoxical reactions. What are the possible side effects of Ativan?Get emergency medical help if you have any of these signs of an allergic reaction to Ativan: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Adverse effects can include sedation and hypotension; the effects of lorazepam are increased in combination with other CNS depressant drugs. Five participants in a sleep study were prescribed lorazepam 4 mg at night, and the next evening three subjects unexpectedly volunteered memory gaps for parts of that day, an effect that subsided completely after 2–3 days' use.