What intravenous (IV) medications can be used to manage claustrophobia during Magnetic Resonance Imaging (MRI) when lorazepam (Ativan) is not an option?

From the Guidelines

Midazolam is the most appropriate alternative to lorazepam for managing claustrophobia during MRI, given its rapid onset of action and shorter recovery time compared to other options. Several intravenous medications can effectively manage claustrophobia during MRI when lorazepam is not an option.

Key Medications for Claustrophobia Management

• Midazolam (Versed) is often the first alternative, typically administered at 1-2 mg IV initially, with additional 0.5-1 mg doses as needed (maximum 5 mg) 1.
• Diazepam (Valium) can be given at 2-10 mg IV, though it has a longer duration of action.
• For patients with contraindications to benzodiazepines, propofol can be used at 10-20 mg IV boluses titrated to effect, but requires anesthesia supervision due to potential respiratory depression.
• Dexmedetomidine is another option, administered as a loading dose of 1 mcg/kg over 10 minutes followed by 0.2-0.7 mcg/kg/hr infusion, providing sedation without significant respiratory depression.
• Diphenhydramine (25-50 mg IV) may help with mild anxiety but is less effective for severe claustrophobia. These medications work by enhancing inhibitory GABA neurotransmission (benzodiazepines), modulating multiple neurotransmitter systems (propofol), or activating alpha-2 adrenergic receptors (dexmedetomidine) to reduce anxiety and induce sedation.

Considerations for Sedation

• The choice of medication should be based on the patient's medical history, current condition, and the potential risks and benefits associated with each medication.
• Monitoring of vital signs and oxygen saturation is crucial during sedation, especially when using medications like propofol that can cause respiratory depression.
• Anesthesia supervision is required when using propofol due to its potential for significant respiratory depression. Given the most recent and highest quality evidence available, midazolam stands out as a preferred option due to its efficacy, rapid onset, and relatively shorter recovery time 1.

From the FDA Drug Label

5 mg should be given over a period of no less than 2 minutes. Wait an additional 2 or more minutes to fully evaluate the sedative effect. If additional titration is necessary, it should be given at a rate of no more than 1 mg over a period of 2 minutes, waiting an additional 2 or more minutes each time to fully evaluate the sedative effect. For continuous infusion, midazolam 5 mg/mL formulation is recommended diluted to a concentration of 0.5 mg/mL with 0.9% sodium chloride or 5% dextrose in water. Usual Adult Dose: If a loading dose is necessary to rapidly initiate sedation, 0.01 to 0.05 mg/kg (approximately 0.5 to 4 mg for a typical adult) may be given slowly or infused over several minutes.

Midazolam can be used as an IV medication to manage claustrophobia during MRI when lorazepam is not an option. The dosage should be titrated to the desired effect, with a usual adult dose of 0.01 to 0.05 mg/kg for a loading dose, and a maintenance infusion rate of 0.02 to 0.10 mg/kg/hr 2.

• The initial dose should be given over a period of no less than 2 minutes, with additional titration as needed.
• The infusion rate should be adjusted to the desired level of sedation, taking into account the patient’s age, clinical status, and current medications.
• Close monitoring is necessary, especially in pediatric patients and those with severe systemic disease or debilitation.

From the Research

IV Medications for Claustrophobia during MRI

• Besides lorazepam, other IV medications can be used to manage claustrophobia during MRI, including:
  • Diazepam, as studied in 3, which was found to be a safe, predictable, and highly effective method of obtaining a successful result in patients with claustrophobia
  • Propofol, as compared to dexmedetomidine in 4, which was found to effectively reduce anxiety levels in claustrophobic adults undergoing MRI
  • Dexmedetomidine, also studied in 4, which was found to be effective in reducing anxiety levels, but may have an effect on image quality and has a higher risk of adverse effects such as hypotension and bradycardia

Non-Pharmacological Interventions

• Non-pharmacological interventions, such as cognitive-behavioral therapy, as reported in 5, can also be effective in managing claustrophobia during MRI
• Other interventions, such as patient education, relaxation techniques, and audiovisual systems, as studied in 6 and 7, can also be effective in reducing anxiety and claustrophobia in patients undergoing MRI

Considerations for Radiographers

• Radiographers play a crucial role in managing patients with claustrophobia during MRI, and their confidence and experience can impact patient outcomes, as found in 6
• Patient education and supportive discussion prior to the MRI examination can be an effective technique for facilitating scan completion, as identified in 6