CONFIRMING A FALSE-POSITIVE DRUG SCREEN
Can levalbuterol (Xopenex) cause urine to test positive for amphetamines?
—William L. Powell, Orland, Calif.
Drug screens falsely positive for amphetamines have been associated with use of the Vicks inhaler, but a search of the literature reveals no similar association with levalbuterol. However, given the serious consequences of a false-positive drug test, any suspect screening result—especially if based on a rapid immunoassay technique—should be confirmed by mass spectroscopy and gas chromatography (admittedly more expensive and time-consuming). For more information, see Weaver MF, Jarvis MAE. Overview of the recognition and management of the drug abuser. In: Rose BD, UpToDate. ed. Wellesley, Mass.: 2008.
—Reuben W. Zimmerman, PA-C (116-1)