Sublingual Zolpidem for MRI in Claustrophobic Patients: A Prospective, Non-Randomized Noninferiority Study

Claustrophobia during MRI may lead to examination interruption, motion artifacts, prolonged acquisition time, and reduced diagnostic quality, frequently requiring intravenous sedation to ensure successful examination completion and adequate image acquisition. A pharmacological alternative that could maintain examination completion while reducing procedural complexity would be beneficial.

To determine whether sublingual zolpidem is noninferior to conventional intravenous sedation for successful MRI completion in claustrophobic adults and to evaluate safety outcomes and procedural costs.

Prospective, open-label, non-randomized noninferiority clinical trial.

282 claustrophobic adults undergoing clinical MRI, 229 of whom received sublingual zolpidem while 53 underwent conventional intravenous sedation.

1.5-T; institutional imaging protocols.

Claustrophobia severity was assessed using a Claustrophobia Questionnaire. Successful MRI completion without interruption due to claustrophobia was the primary endpoint. Physiological parameters (heart rate, blood pressure, peripheral oxygen saturation, blood glucose) were evaluated before and after MRI examination. A structured post-examination questionnaire was used to assess adverse events and direct procedural costs were evaluated from institutional administration records.

Continuous variables were analyzed using Student's t-tests, while categorical variables were analyzed using chi-square or Fisher's exact tests. Noninferiority was assessed using a predefined margin of -10%. Statistical significance was defined as p < 0.05.

There was no significant difference in the claustrophobia severity score between groups (p = 0.235). MRI completion was achieved in 96.9% (222/229) of patients receiving zolpidem and 100% (53/53) of patients receiving conventional sedation. The absolute difference between groups was -3.06% (95% confidence interval: -5.29% to -0.83%), remaining within the predefined noninferiority margin. No respiratory compromise occurred in either group. Mild adverse events occurred in 20.7% of zolpidem-treated patients, mainly dizziness (8.5%). Mean procedural cost was significantly and substantially lower with zolpidem (USD 0.16) than with conventional sedation (USD 114.27).

Sublingual zolpidem was noninferior to conventional intravenous sedation for MRI completion in selected claustrophobic adults, demonstrating favorable safety and substantially lower procedural cost.

2.

Stage 5.

The trial was registered at the (ReBEC) under registration number RBR-23pfcg5.