Lorazepam (Ativan) is an IV, IM, and oral benzodiazepine medication which potentiates the GABA(A) receptor resulting in anxiolysis, sedation, amnesia, and muscle relaxation. Since lorazepam has limited lipid solubility but is highly protein-bound, it tends to remain in the intravascular space resulting in sustained peak effects. Its metabolites are also largely inactive.
As a cardiothoracic anesthesiologist, I administer midazolam (a different benzodiazepine) for perioperative anxiolysis and sedation. As an intensivist, I will order lorazepam as an emergent initial anticonvulsant therapy for patients in clinical status epilepticus. One must be cautious due to benzo-induced respiratory depression, especially in patients with obstructive sleep apnea.
In general, I dislike benzodiazepine infusions for sedation in patients on mechanical ventilation due to unfavorable context-sensitive half-times and deliriogenic potential. In particular, lorazepam drips can cause hyperosmolality and anion gap metabolic acidosis from the propylene glycol solvent intoxication. Instead, I opt for analgosedation options like dexmedetomidine, ketamine, propofol, etc.