What dose of Ativan (lorazepam) is recommended for a 71-year-old female with claustrophobia prior to a cardiac Magnetic Resonance Imaging (MRI)?

Lorazepam Dosing for Claustrophobia in a 71-Year-Old Female Prior to Cardiac MRI

For a 71-year-old female with claustrophobia undergoing cardiac MRI, administer 0.5-1 mg oral lorazepam 30-60 minutes before the procedure. 1

Rationale for Dosing

The FDA-approved dosing for lorazepam in elderly patients specifically recommends:

• Initial dosage of 1-2 mg/day in divided doses for elderly or debilitated patients 1
• For situational anxiety (such as MRI-related claustrophobia), a single dose is appropriate
• Lower doses are recommended in the elderly due to:
  • Increased sensitivity to benzodiazepines
  • Higher risk of adverse effects
  • Altered pharmacokinetics in older adults

Timing of Administration

• Administer 30-60 minutes before the scheduled MRI to allow for peak effect
• Peak anxiolytic effect occurs within 1-2 hours of oral administration
• This timing allows for optimal anxiolysis during the procedure while minimizing post-procedure sedation

Special Considerations for Elderly Patients

• Start with the lower end of the dosing range (0.5 mg) for patients:
  • Over 70 years old
  • With hepatic or renal impairment
  • Taking other CNS depressants
  • With respiratory conditions
• Consider 1 mg for patients with more severe claustrophobia or prior failed MRI attempts

Monitoring Requirements

• Assess vital signs before administration
• Monitor for excessive sedation, respiratory depression, and hypotension
• Ensure patient has transportation home after the procedure
• Do not allow the patient to drive for 24 hours after receiving lorazepam

Alternative Approaches

The European Society of Cardiology recognizes that approximately 5% of patients experience significant claustrophobia during MRI procedures 2. If oral lorazepam is contraindicated or ineffective, consider:

• Intranasal midazolam (1-2 mg) has shown 97-98% success rates in facilitating MRI in claustrophobic patients 3, 4
• Non-pharmacological approaches including:
  • Pre-procedure familiarization with the MRI environment
  • Positioning the patient feet-first into the scanner
  • Use of prism glasses to see outside the scanner
  • Having a companion present during the procedure

Contraindications and Cautions

• Avoid lorazepam in patients with:

  • Severe respiratory insufficiency
  • Sleep apnea
  • Myasthenia gravis
  • Severe hepatic impairment
  • History of substance abuse
  • Concurrent use of strong CYP3A4 inhibitors

• Use caution with concomitant medications that may potentiate sedative effects

Common Pitfalls to Avoid

1. Overdosing elderly patients: Starting with standard adult doses can lead to excessive sedation, respiratory depression, and increased fall risk

2. Inadequate timing: Administering lorazepam too close to the procedure time may result in insufficient anxiolysis

3. Failure to arrange transportation: Patients should not drive after receiving lorazepam

4. Neglecting non-pharmacological approaches: Combining medication with reassurance, explanation of the procedure, and environmental modifications improves success rates

5. Inadequate monitoring: Elderly patients require close observation for adverse effects

By following these guidelines, the cardiac MRI can be successfully completed while minimizing both claustrophobia-related distress and medication-related adverse effects in this 71-year-old female patient.