What is the protocol for a PRN (as needed) order for Ativan (lorazepam)?

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From the Guidelines

A PRN order for Ativan (lorazepam) should be written as 0.5-1 mg orally four times a day as required, with a maximum dose of 4 mg in 24 hours, as recommended by the BMJ study 1. When managing anxiety or agitation, it is essential to consider the patient's ability to swallow and their overall health status.

  • The dose of lorazepam can be adjusted based on the patient's age and medical condition, with a reduced dose of 0.25-0.5 mg recommended for elderly or debilitated patients, with a maximum dose of 2 mg in 24 hours 1.
  • Oral tablets can be used sublingually, which is an off-label use, but may be necessary in certain situations 1.
  • It is crucial to monitor the patient's vital signs, including respiratory rate and blood pressure, after administration of lorazepam, as it can cause respiratory depression and hypotension.
  • The medication should be prescribed for the shortest duration necessary, and patients should be regularly reassessed for continued need, due to its potential for dependence and tolerance.
  • The specific indications for use, such as "for moderate to severe anxiety" or "for agitation," should be included in the PRN order, along with the medication name, dose, route, frequency, and maximum daily dose.

From the Research

PRN Order for Ativan

  • A PRN (pro re nata) order for Ativan (lorazepam) is typically used to manage anxiety, agitation, or insomnia on an as-needed basis.
  • The dosage of lorazepam can vary depending on the individual's response and medical condition, with typical doses ranging from 0.5 to 2 mg orally, as seen in studies 2.
  • In elderly individuals, long-term use of lorazepam can lead to adverse cognitive effects, such as impaired memory and psychomotor performance, as reported in a study 3.
  • The effects of lorazepam on cognitive performance can also vary depending on age, with older individuals showing significant impairments in dual-task performance, as found in a study 4.
  • Lorazepam has been shown to be effective in managing acute agitation, with improvements in outcomes related to agitation, although the combination of lorazepam and haloperidol may be superior to either agent alone, as seen in a systematic review 5.
  • The safety profile of lorazepam is well-characterized, with common adverse events including dizziness, sedation, and somnolence, as reported in multiple studies 6, 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Acute lorazepam effects on neurocognitive performance.

Epilepsy & behavior : E&B, 2012

Research

Neurochemical and behavioral effects of lorazepam: A dose related study.

Pakistan journal of pharmaceutical sciences, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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