Supplementary Material for: The Impact of Drug Interactions on the results of DAT-SPECT Imaging in a Specialty Movement Disorders Practice: A Retrospective Analysis of Outcomes

Introduction: DAT-SPECT imaging is approved as a diagnostic tool for the evaluation of suspected Parkinsonian syndromes, but the FDA approved package insert lists 16 potential drugs that may interfere with the image obtained. The clinical impact of these drugs upon imaging results has not been established. This study aims to determine the accuracy of DAT-SPECT imaging in assessing presynaptic dopaminergic denervation in the setting of these drugs. Methods: This is a retrospective chart review of patients at a single center who underwent DAT-SPECT imaging while taking “contraindicated” drugs between December 2012 to December 2022. Results: A total of 1224 charts were screened, and 153 (12.5%) charts met the inclusion criteria. Bupropion (32%, n=49) and sertraline (26%, n=40) were the most common contraindicated drugs. The false positive rate was 9.2%. Conclusion: This retrospective analysis supports the concern that certain drugs may interfere with DAT-SPECT imaging results, leading to potential false positives. This has implications for how clinicians interpret DAT-SPECT imaging in patients taking these medications and whether they should advise patients to stop these medications before a scan is performed.