MSACL 2023 Abstract

Introduction:
Solriamfetol is used to treat excessive daytime sleepiness (EDS) caused by narcolepsy and residual EDS caused by obstructive sleep apnea/hypopnea syndrome (OSA) despite other treatment. As a schedule class IV-controlled substance, care is taken when prescribing solriamfetol due to the potential for abuse. As such, urinary toxicology screens are monitored during treatment to assess for other illicit substance use. Our providers became concerned when a patient prescribed solriamfetol had a urinary toxicology screen that was positive for amphetamines despite patient denial of illicit drug use. This raised a question regarding a false positive amphetamine screen.

Objectives:
Herein, we tested the effect of Solriamfetol drug (150mg/ml) on the amphetamine assay on the Beckman AU 480 and Citrine™ Triple Quad™ MS/MS Systems.

Methods:
We performed spiking studies with Solriamfetol drug on negative urine. The stock solution of Solriamfetol drug (150mg/ml) was prepared in Phosphate-Buffered Saline. The different concentrations of Solriamfetol drug ranged between (2mg/mL, 200ug/mL, 2ug/mL, 200ng/mL respectively). We then tested each concentration for amphetamine immunoassay on the Beckman AU 480 and the LC/MS-MS. The amphetamine immunoassay on the Beckman AU480 is the Emit® II Plus and the amphetamine assay on the LC/MS-MS was performed on SCIEX Citrine™ Triple Quad™ MS/MS Systems is a laboratory developed test.

Results:
Our data suggests that the amphetamine immunoassay on the Beckman yielded positive results for Solriamfetol at concentrations of 2mg/ml and 200ug/ml and negative results at 2ug/ml and 200ng/ml. However, the Citrine™ Triple Quad™ MS/MS Systems was negative at all concentrations.

Conclusion:
The Beckman AU480 Emit® II Plus amphetamine immunoassay gave false positive results for amphetamines due to Solriamfetol drug usage.