From the Research
For optimal sedation with 2 mg sublingual Ativan (lorazepam) prior to an MRI, administer the medication approximately 60-90 minutes before the scheduled scan time. This timing allows the medication to reach peak effect when needed, as sublingual lorazepam typically begins working within 15-30 minutes, but maximum anxiolytic and sedative effects develop around 1-2 hours after administration 1. The most recent and highest quality study available does not directly address the optimal timing for administering sublingual lorazepam prior to MRI, but based on the pharmacokinetics of the drug, administering it 60-90 minutes before the scan is likely to provide the best sedative effects.
Key Considerations
- Patients should be monitored after receiving the medication and should not drive themselves home following the procedure.
- It's essential to inform the MRI staff that sedation has been administered.
- The effectiveness of lorazepam for MRI sedation stems from its action on GABA receptors in the brain, enhancing inhibitory neurotransmission to reduce anxiety and produce sedation.
- Some patients may require dose adjustments based on their age, weight, medical conditions, or previous response to benzodiazepines, such as elderly patients or those with liver impairment who may need reduced dosing to prevent excessive sedation 2.
Sedation Protocol
- A standard sedation protocol in MRI centers is associated with a more appropriate drug choice, as well as optimized monitoring and post-procedure care 1.
- The use of midazolam, another benzodiazepine, has been studied in the context of MRI sedation, but the focus here remains on lorazepam due to the question's specificity 3.
- Other methods of sedation, such as oral glucose administration in newborns, have shown effectiveness in certain contexts but are not directly relevant to the administration of sublingual lorazepam in adults or children outside of the newborn period 4.