Diphenhydramine (Benadryl)
Drug Testing
SUMMARY #
U.S. DRUG TESTING SUMMARY | |
Diphenhydramine | |
Tested for in Standard Drug Tests? | NO |
Tested for in Extended Drug Tests? | NO |
Possible to Test for? | YES |
Will Trigger Tests for Other Substances? | Yes : Benzodiazepines, PCP, Tricyclic Antidepressants |
Detection Period in Urine | 2-4 days (single use) |
FALSE POSITIVES #
Possible False Positives Triggered
Diphenhydramine, especially at high doses, has been reported to cause false positives for Benzodiazepines (such things as Xanax or Valium) 1. The false positives occur using the screening-type tests (sticks, cups, etc) but confirmatory tests using GC/MS and other more rigorous techniques should clear any false positive. Other sources list Diphenhydramine as a possible source for false positives for PCP2 and tricyclic anti-depressants3.
CAUTION & DISCLAIMER #
Erowid's drug testing information is a summary of data gathered from site visitors, journal articles, websites, and other resources. Detection periods depend on amount and frequency of use, metabolic rate, body mass, age, overall health, drug tolerance, and urine pH of each individual. Many substances that are not tested for in basic or extended urinalysis tests CAN be tested for by a laboratory willing to go to the trouble, although that is uncommon.
RELATED RESOURCES #
RELATED LINKS #
References #
- NHB. "False Positive Urine Screen". Erowid Experience Report 77774. March 2009. [ Full Text ]
- Sena SF, Kazimi S, Wu AH. "False-positive phencyclidine immunoassay results caused by venlafaxine and O-desmethylvenlafaxine." Clin Chem. 2002;48(4):676-7.
- Sorisky A, Watson DC. "Positive diphenhydramine interference in the EMIT-st assay for tricyclic antidepressants in serum [letter]". Clin Chem. 1986;32(4):715. [ Full Text ]