Lorazepam and the Dexamethasone Suppression Test
Lorazepam (a benzodiazepine) can affect results of the dexamethasone suppression test (DST). [2]
In a DST sensitivity study, DST suppression status changed after a short lorazepam course followed by abrupt lorazepam discontinuation, indicating that lorazepam exposure around DST testing can alter DST interpretation. [2]
Evidence of Lorazepam-Related DST Change
A pharmacologic provocation study reported that after 3 days of lorazepam, repeating the standard DST after abrupt lorazepam discontinuation led to additional patients changing from suppression to nonsuppression. [2]
That study also found DST sensitivity improvement (reported as an increase in sensitivity) after modifying test timing around lorazepam, supporting an effect of lorazepam on DST performance. [2]
Clinical Implications for DST Interpretation
Because benzodiazepines can influence hypothalamic-pituitary-adrenocortical (HPA) activity, DST results obtained in close temporal proximity to lorazepam treatment can be unreliable for distinguishing adrenal suppression versus true DST non-suppression. [1]
Practical Considerations for Ordering and Timing
When the DST is clinically important, benzodiazepine use (including lorazepam) should be treated as a potential interfering medication and DST timing should be coordinated with prescribing clinicians to minimize drug-related DST misclassification. [1], [2]