From the Research
For MRI anxiety, Ativan (lorazepam) is typically administered orally at a dose of 0.5 to 2 mg, given 30-60 minutes before the procedure, as supported by the study 1 which found that lorazepam was the most commonly used anxiolytic for adult outpatient MRI examinations.
Key Considerations
- The exact dose depends on the patient's age, weight, and anxiety level, with lower doses (0.5-1 mg) often sufficient for mild anxiety and higher doses (1-2 mg) for more severe cases, as noted in the example answer.
- Elderly patients or those with liver impairment should receive lower doses, usually starting at 0.5 mg, due to the potential for increased sensitivity to the medication.
- Oral administration is preferred for outpatient MRI procedures due to its convenience and adequate absorption, as mentioned in the example answer.
- Ativan works by enhancing the effect of GABA, an inhibitory neurotransmitter in the brain, which reduces anxiety and produces a calming effect.
Important Precautions
- Patients should arrange for someone to drive them home after the procedure as Ativan causes drowsiness and impairs coordination.
- They should also inform their healthcare provider about any medications they're taking and any history of substance abuse, as Ativan can interact with other drugs and has potential for dependence.
Additional Evidence
- A study from 2021 2 found that the use of a wide-bore magnet increased the odds of successfully completing an MRI brain examination in mild, moderately, and severely claustrophobic patients, and the administration of pre-examination low-dose oral benzodiazepine increased the odds of successfully completing the examination in severely claustrophobic patients.
- However, the most recent and highest quality study 3 compared the clinical outcomes of midazolam and dexmedetomidine combined with ropivacaine-induced thoracic paravertebral nerve block in radical lung cancer surgery, and found that dexmedetomidine was superior to midazolam for sedation, anti-inflammation, and anti-stress in elderly lung cancer patients, but this study is not directly related to the use of Ativan for MRI anxiety.