Efavirenz treatment and false-positive results in benzodiazepine screening tests.
We investigated the effect of efavirenz treatment on the results of drug screening tests of urine samples obtained from 100 patients infected with human immunodeficiency virus. Of 50 patients who received efavirenz, 49 tested positive for benzodiazepines in > or =1 drug screening test, whereas of 50 patients who did not receive efavirenz, only 1 tested positive for benzodiazepines in > or =1 drug screening test. The major metabolite 8-hydroxy-efavirenz is responsible for this cross-reactivity.
Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg 69120, Germany.
Antje
A
Blank
Victoria
V
Hellstern
Dieter
D
Schuster
Martin
M
Hartmann
Anne K
AK
Matthée
Jürgen
J
Burhenne
Walter E
WE
Haefeli
Gerd
G
Mikus
D000480:Alkynes; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000032:analysis*; D048588:Benzoxazines / Q000627:therapeutic use*; D003521:Cyclopropanes; D005189:False Positive Reactions; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000175:diagnosis*; D014556:Urine / Q000737:chemistry*
D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D001569:Benzodiazepines; C098320:efavirenz